MGB GT splash panel replacement; fitting a motorised automatic aerial

My splash panels have rusted through at the bottom. This is a real shame as the rest of the panels are in first class condition. A little more preventative attention here would have seen them last in tip top condition and mean that I wouldnt need to do this job. As its a small problem I could repair with GRP matting, but the splash panels themselves are cheap enough and as I have to remove one at least to swap the radio aerial, I may as well replace them at the same time.

The splash panels are a bolt-in fit on their inside edge with a silicone rubber seal down the external sides to bridge against the wing. In my case the panel was held on by 3 hex headed bolts up the side and a large cross-head screw at the base. This is a daft system; if anywhere is guaranteed to corrode its the bottom bolt and this proved to be the case. I bought a new fitting kit for each side and note that this now supplies 4 hex headed bolts!

The three side bolts unscrewed easily with a 7/16Ww socket, the bottom screw head wouldn't shift and as expected stripped the head. The usual approach here would be to use an impact hammer but obviously body components are far too delicate for this. I tried cutting a new groove with a Dremell but that stripped out too and so in the end I had to drill the head off and remove the shaft of the bolt as best I could- this turned out to be not very well!

Bottom cross headed bolt RHS splash panel tight up against wing edge, rust damage to panel visible above

One of the panel mounting bolts (hex headed) RHS splash panel. Clean it off and it came out easily enough

 I found I couldn't remove the bottom bolt, but when the top three were removed the top of the panel came away anyway! This left the rusty stump of the panel still attached to the mounting flange by the bolt. In the end I had to drill this out- not a pretty job!

Remnants of RHS splash panel still bolted to body flange.

Base of  other side panel (LHS), bolt no 1 visible, cross headed bolt is tucked in under, rust holing visible this side also.

End of Castle rail LHS seen from below the car- bottom cross headed bolt visible in recess of front wing on centre left.

 The RHS  splash panel came off easily with its body seal. Note bottom section has detached through rust.




Looking inside the RHS wing there was a lot of dirt and debris that will need raking out before the area can be cleaned and stabilized before fitting the new panel. The aerial is visible inside the wing. The mast clamp has failed and it just drops through the mounting now. I want to replace this and will fit a new automatic aerial. These require an under hang of around 28cms but there seems to be plenty of room here so I will go ahead and order the new aerial.

Old aerial in place- the black tube (top) is the original container for the telescopic aerial but this has now lost its grip and the aerial now drops right through- chrome mast visible beneath. Note the narrow channel gap at the bottom formed by the outer wing and the forward projection of the sill.

Fitting an automatic aerial

I bought the Autoleads RMA 1001 compact automatic aerial- it was a good price at around £30 and came with a variety of grommets to suit virtually any shape of panel. If it has a problem, its that it comes fitted with the thinnest wires imaginable- I guess this is the minimum amount of wire for the current- but its so thin it doesn't really work in the even the red sized crimp connectors unless  doubled-up. Even then its not the most secure connection so I had  to make soldered connections to a thicker wire if I wanted to fit a bullet say to preserve options for disconnection.

Removing the old aerial was simple enough

Unscrew top bolt

Aerial drops into wing beneath

The old aerial was cut out leaving the coaxial lead in place to act as a guide for the cable routing.

I traced the route of the old coax from the console

 around the back

 across and above the steering column and then taped to a cross beam

 before finally diving beneath the footwell side trim right at the top. The cable exits to the wing cavity through a grommet hidden below the trim. It was necessary to loosen the trim to allow the cable to move. I unscrewed the three self tapping screws down the door pillar edge. There is a fourth right up next to the windscreen wiper motor that's virtually impossible to get to but needs to come out to provide leeway to move the cables. My thumb and finger here are pointing at two of the screws.

In an ideal world I would probably have preferred the blue switching lead to follow the coax into the cabin, whilst the red and black power and earth leads went into the bonnet space to connect at the fusebox. However it wasn't possible to get a drill into the wing space to drill through and so I had to route all cables through the grommet and into the cab.

It wasn't as bad as it sounds but its tricky to refit the grommet with so many leads passing through it.

The antenna will be held by the chrome nut at the mast base above the wing and also by a metal strap inside the wing cavity. This latter wasn't going to fit in a useful position so I had to grind the edges down until it would fit over the mounting stud and hang vertically.

I could then offer up the antenna and hold it loosely in place with the chrome nut.

Holding the antenna in place and adjusting the angled lower mounting for the best match with the body profile

Fit the rubber cushion, and lugged profile before adding the chrome cover plate. Make sure that the cover plat covers as much of the hole as possible and then tighten the nut- but not fully at this stage

Once the antenna was held I could fit the metal strap below.

|Loose fitting- antenna dangling from mast base nut above wing.

I bent the strap into a "Z" shape and them drilled a small hole through the strap and end bulkhead allowing me to fit the strapping with a self tapping screw.

Metal strap bent to Z" profile and screwed to bulkhead.

...before I neatened up the wiring as best I could. Its very easy to get this tangled! I pulled most of the excess above into the car and connected the blue antenna signal lead to that I had already prepared from the ISO connector.

The bottom of the antenna has a drain hole- it comes with a short length of tubing but this would serve no useful purpose in this position. I attached a longer tube using superglue to keep it in place. This will be routed out of the cavity and below the splash panel.

Wires neatened up and pulled through. I also found that a single screw in the strapping wasn't enough to prevent sideways movement so I fitted a second.

 All the wires were now routed into the cab. There was a convenient earth connection in the pedal box below the wiper motor where a hole was already present. I inserted a bolt and fixed an eye connector to the aerial earth to make the connection.

For the live connection I required a permanently live feed.  There was a permanent live available under the dash (pink wire entering both multi-plugs) but I was unsure whether inserting a join here would be a problem as there wasn't much spare wire length to play with. To be safer I routed the wire through the loom grommet and into the engine bay. Using a curtain wire to feed through the grommet gave me a lead first time even though its cramped just here behind the servo! I was then able to route the wire alongside and secured to the existing loom towards the fuse box.  Here I found the same pink wires were supplying fuse no 4. In order to avoid any potential overloads  on this fuse I connected the antenna live wire to the supply side of the fusebox using a piggyback spade connector and fitted its own a 3.5a in-line fuse into the feed.

Antenna feed wire routed alongside loom and fitted with it sown in-line fuse (3.5a). Fitted here the fuse holder lines up with the existing in line fuses  fitted to the car.

Piggyback spade on supply side of fuse no 4.(lowest left in this pictire)

Although my radio isn't yet properly installed I connected it temporarily to verify that the antenna extended and retracted when the unit was turned on and off. It did so - so very satisfactory!

Fitting the new Splash panel

Having already removed the bulk of the splash panel, I was left with the rusty fragment and corroded mounting bolt. I drilled out the bolt head releasing the stump of the splash panel. It was tricky but with care I managed to drill through the remnants of the stub and the weld nut on the other side.

Stud of bolt drilled out- not very pretty

I enlarged the hole with a 17/64 drill and then tapped it to 5/8 NC18

At this stage I was obliged to call a temporary halt and  as I want to be able to use the car (storms are forecast) I didn't want to have the inside of the wing completely exposed. I refitted the old splash guard temporarily, and fitted a bolt into my newly tapped hole to keep the muck out.

When I got a chance it was easy- if very mucky to clean out the cavity and wire brush the metal edges to remove any loose rust. I treated all the lower areas-especially the lower mounting flange and the ends of the castle rail where the underseal has come off, with rust converter and then applied a coat of  Hammerite to the metal. As an aside I will add that this is virtually the last of my original hammered enamel from Finnigan's Speciality Paints in Prudhoe Northumberland- and bought BEFORE the company was bought out. Modern Hammerite is similar in name only in my view and I am really sorry to have run out of the original. The aerosols of the modern stuff are the worst- they seem to have virtually no pigment and little if anything in the way of rust-inhibiting properties.
My view anyway-rant over!

I also painted both sides of the new splash panels in the same paint. The tops of these don't really rust so I clamped them upside down to make sure I got a good coating on the bottom and edges. Turn them round after 24hrs and paint the other ends.

I sprayed inside the wing with Waxoyl from a warmed and well shaken aerosol can

 The sill projects forwards into the bottom of this space and this creates a narrow gap with the outer wing towards the bottom. This area is a notorious rust trap. I feel it needs protection, but its important not to clog it with wax as it also needs to drain. I sprayed it and worked the wax down into the gap with a long plastic tie strip, raking the wax forwards so I could tell that it isn't blocking the channel.

Checking that the gap between wing and sill is clear, whilst still protected with waxoyl.

 The new splash guards are ready- they will fit either side, but it seems that its best to fit them such that the reinforcing mouldings bulge outwards (ie convex side) towards the wheel so that they don't collect road muck.

The edges are always the most vulnerable because paint tends to be thinner here. I lined the edge of the panel with a bead of grease that will stay inside the sealing strip and hopefully protect.

... and then fitted the sealing strip. I overlapped it at the top

... and only cut it when it was fitted so that the cut edge can follow the line of the panel


I put some corrosion block grease into all the bolt holes and spread it up the mating edge so that it will be between the panel and the wing.

 Then I offered up the panel, fitting the top bolt first and working downwards.

Its necessary to bend the bottom of the splash-guard so that it follows the contours of the body and lines up with the bottom bolt hole. I cut the bottom of the sealing strip to fold neatly around the bottom of the guard when its folded, but still permitting some drainage.



Finally I bent the bottom edge into place and fixed the larger bolt I had selected into my re-tapped mounting. Note anti rust treatment on the end of the castle rail.

Splash-guard installed.

I should add that predictably the passenger side lower mount screw was also rusted and degraded. I tried to remove it as before but this time the drill bit broke off inside the bolt and could not be removed. Since the drilling was probably not concentric and straight its likely that the stub of drill is now wedged across the thread, partially in the stud and partially in the weld nut. In this position it would stop me unscrewing the stud (even if I could grab it) and its far too hard to let me drill it out. I'm therefore completely stymied on this and I'm proposing to leave it as it is and fit a rivnut for a new fastening.

New rivnut installed- remains of former stud below it

Passenger side splashguard installed

New allen cap screw (stainless) inserted in Rivnut

Centre and radio consoles seatbelt warning light and radio installation/removal.

The immediate problem I have is that the seat belt warning light doesn't illuminate following my repair of the map/courtesy light. Clearly something is disconnected so I have to dive in again to sort it. This is also a voyage of discovery and I found a few things that I will add to the list for a future fix!

 This is the problem, the radio console has warning lights at the base. The handbrake light (rhs) works fine and the seatbelt light (lhs) doesnt!

 To remove the radio console you need to remove the centre console first. Open the armrest and remove the single screw towards the back

 Then remove the 4 chromed screws holding the gear gaiter retaining ring. Note the shortest screw fits towards the front. The ring  can then be wriggled out leaving the flexible gaiter which will fold and pass through the console allowing the console to be lifted away.

This gave me my first surprise- there is the best part of half an old cushion down here! I'm guessing this is either to take up slack or to stop noise/vibration- maybe all three. It shouldn't be here and presumably implies something is wrong. I'm suspecting that the nylon bush at the base of the gear lever may be worn- or possibly some problem with the anti-rattle spring/plunger. I don't (yet) understand these as the antirattle spring and plunger isn't always shown on the parts diagrams so I'm not really sure whether I am supposed to have one in this car and where it should go if I do. As I don't want to end up with a car I can't drive home this will have to wait.

Similarly the state of the wiring to the overdrive switch is shocking- I have already repaired breaks at the top end under the overdrive switch itself but it seems there are several more splicings down here all bound up in bulky and sticky insulating tape. The whole lot needs to be renewed- probably with more flexible silicone covered wiring. Its another job I will earmark for later.

 To remove the two heater control knobs press the small button (indicated below) on their sides inwards with a blunt probe of some sort.

 The knobs then just pull forwards

 

Each heater valve control is held on by a ring nut and two washers, one plain, one spring. Use a box spanner to remove the ring nut and then remove the fittings

You can then remove the console and to do this you need to remove the two screws each side at the rear.

The console then pulls forward. 

The clock connections can be undone to provide some movement

Clock connections, bulb holder removed, live connection to top of clock, black earth at the bottom.

There should be enough slack in the radio connections to permit the console to come forward far enough to attend to the various bulbs behind. If not then it should be a simple matter to disconnect the multiplugs to release it. Sadly in my case there was not only insufficient room but also no multiplugs! A quick investigation revealed a spaghetti nightmare of  re-jigged wiring that had been used to install the radio. Further it was only poorly mounted and the mounting sleeve pulled out as well. I had no choice but to remove it all and try to sort it out. In fact I would like to install an age-appropriate radio cassette anyway, so this is a good opportunity to sort out the wiring in preparation for that.

Nightmare wiring behind the radio

 I'm including several reference shots here to help my reconnection. The basic problem here is that this is a modern radio with a pair of standard 8 pin ISO connectors that should fit into any car... well any car made after 2003 that is, and naturally the MGB hasn't got the appropriate connection plugs. This means that the installer has simply chopped the wires  and spliced them into the loom (with a few new ones for good measure) using domestic wiring block connectors. It works; but it's not pretty and it will be a nightmare every time anyone wants to modify or swap the sound system. So the answer is to fit the car with the female ISO counterparts, connected up (as far as is possible in an old car) in the standard manner.

Wiring- note one ISO (the power connector) has been removed entirely, the other (speakers) is present but 4 of its 8 wires have been cut and rewired into the block connector. These are the front speaker wires, green/greenblack and white. The rear speaker wires are not used as this car has no rear speakers!

Block connector, LHS white wires and gn gn/blck  speaker connections to door speakers. Block connects to the white/pink duplex wires serving each speaker. At the rhs side the red (switched power in to radio) is connected  to  a green white power connection via an in line fuse and is live via the ignition switch "on" and in the accessory position.

Blue white remote control or antenna control wire is not connected.

 The yellow wire (12v constant in)  from the radio is spliced via its own block connection to the new red/white wire that picks up a live feed from the map light as I found when I fixed that.

Black wire connected via its own block to an earth lead- attached to a screw in the rear panel visible right, just below another (black) in-line fuse. This screw is I think also the rear support for a radio.

Note the black in line fuse holder  inserted in the red/white power lead (rhs) that picks up its feed from the map light splice (pink lead bullet connector to red live feed to map light). This is the always live feed.

Having removed these connections I will connect the car's wiring to female ISOs so that any future radio can be simply plugged in.


During the process of removing the console and radio I found the seat belt warning light bulb holder was simply disconnected from its socket and should be an easy fix- at least that accomplishes my original mission so I was able to reinstall the consoles (without the radio) and wait for the new connectors to wire in. In the meantime here is the standard wiring connections and colours for the ISO connectors.

Picture courtesy of james Beckett (By James Beckett - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=18437466)
Note that the connectors are different and are distinguished by the position of the lhs clip: in type A the clip is at the bottom and type B (for speakers) have it centrally located.

Picture courtesy Estimamike http://i16.photobucket.com/albums/b3/estimamike/EPC%20stuff/ISOWiringEd.jpg

1. Power Wires
2. 1. Constant 12V / Memory Keep Alive — yellow
   2. Accessory (switched) — red
   3. Dimmer/illumination — orange w/white stripe
3. Ground Wires
   1. Ground — black
4. Speakers
   1. Right front speaker(+) — gray
   2. Right front speaker(-) — gray w/black stripe
   3. Left front speaker(+) — white
   4. Left front speaker(-) — white w/black stripe
   5. Right rear speaker(+) — purple
   6. Right rear speaker(-) — purple w/black stripe
   7. Left rear speaker(+) — green
   8. Left rear speaker(-) — green w/black stripe
5. Amplifier and Antenna Wires
1. Antenna — blue
2. Amplifier remote turn on — blue w/white strip
3. 
   
4. 
   

1. New ISO connectors male and female are v cheap on Ebay so I bought both. I have now acquired a National radio cassette player from 1984 (new and unused) and this came with its wiring diagram and its pleasing that so many of the colours were already established in 1984. The only differences that I found were that yellow and red wires have swapped places and the striped speaker cables identifying the negative feed in later cars signify the positive in earlier models. I attached a pair of male ISO terminals (they are not interchangeable so make sure you use the one with the centre clip for the speakers) to the radio wires with soldered junctions and covered each in heat shrink.

Wires attached to ISO connectors at rear of radio.

Car wires behind consol attached to ISO female connectors- note spool of blue wire added for later connection to fully automatic aerial.

Speaker wires spliced in to new connector

Power connections/earth spliced into second connector

Whilst waiting to install the radio I did connect it loosely to check it worked... nasty moment when the lights came on but no sound!!! Resolved easily as the fade was set to full rear speakers-I dont have any! Return to full front and it worked perfectly. Removed to await final instalation.

In the meantime and whilst the radio is out is easy to get at the courtesy/map light. I took advantage of this to replace the bulb

The bulb is a mini Edison screw (MES) fitting, I ordered an LED with the same fitting. They are harder to come by as most are push fit 2 pin. LEDs are quite expensive in the UK but much cheaper ones are available from overseas if you can wait- although a word of warning, the Chinese do not understand bulb sizes and the bulbs illustrated in the ad aren't always the ones you will get!

Simple screw in

... and refit the bulb holder. The LED gives a bluer light but much brighter and I now know it wont overheat or drain the battery if left on for too long.

The antenna signal wire is intended to feed the solenoid in an automatic aerial and not the motor. As such its a low current feed and limited to 0.5a. I will be installing an automatic aerial later (see post on splash-guards) and so to guard against idiocy, installing of the wrong aerial or wiring it up wrongly, I installed an in-line 0.5a fuse. Its a shame these fuse holders come pre-wired so you can't avoid a change in flex colour!

0.5a in line fuse installed in blue antenna signal wire.

I also acquired a used Phillips radio cassette from 1985. I connected this up to ISO connectors as well so that I could see which to fit. This radio cassette was simple to connect however it required 4 x 2-pin speaker connecting plugs (one blade one pin) which were missing from the cassette. I bought replacement plugs from Maplins. Cheap enough but unsatisfactory. They are supposed to have screw-in connections but of the 8 screws fitted to the 4 plugs I bought, only 2 actually fitted the threads, the other 6 simply pushed through! I used the plugs but had to solder the connections. One point to note is that although the pin connection is central, the blade connectors are offset and must be refitted in the correct orientation or the plug won't fit the socket! The Phillips radio also powered up and functioned well.

The selection of which radio to fit was however made for me. The car had been fitted with a modern Pioneer CD radio unit which fitted into a sleeve mount. This had necessitated enlarging the opening in the console with the result that the National unit, which predates sleeve mounting, would no longer fit! The Phillips unit made a year later does use a sleeve mounting and so it was the only one that can be fitted without modifying or replacing the console.

The sleeve fitted into the modified opening of the console quite nicely and I fed the wiring connections through to the front. The instructions say to fit  the sleeve by bending the tabs with a screwdriver so that they grip the material of the console. Its not really obvious in this sleeve because the tabs can be bent in a longitudinal direction parallel to the console material not perpendicular to it as the old sleeve had been. However they are designed to fold up at the front as they bend down behind the console so that the wings can then grip the material. In the pic below the tabs have been bent down along the sleeve's long dimension but the fronts have folded upward forming wings to grip the console itself.

Make sure the raised wings are bent down out of the way of the radio before inserting it.

Finally the radio just slides in using all the new connections I have made. During this process I seem to have lost the left hand plastic trim strip but I think this will turn up somewhere in the near future.
All tested and it works perfectly (including the new aerial) although being a used unit it does have a bit of a crackle on the volume control- however its an original and contemporary with the car.