Monday 7 August 2017

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
    1. Constant 12V / Memory Keep Alive — yellow
    2. Accessory (switched) — red
    3. Dimmer/illumination — orange w/white stripe
  2. Ground Wires
    1. Ground — black
  3. 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
  4. Amplifier and Antenna Wires
    1. Antenna — blue
    2. Amplifier remote turn on — blue w/white strip


  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.

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