No main headlights

ok so first of all the grey/yellow wire you found is the power for the fog light switch, its in M plug if you font have front fogs. if you do have front fogs you connect it with the male spade wire of the same colour, and fit a 53 relay to slot 7 on the fusebox. you can do this even if you dont have front fogs but no real need.

if your main beam works fine then there is nothing wrong with headlight switch or wiring to it, as both dip and main beam are fed by the same pin '56' with the white/black wire. This wire goes off to the flasher/beam select switch in the wiper stalk and the indicator stalk has a little hook in the base of it which clips onto it.

first thing is make sure the hook is clipped on properly, you should feel the flasher switch make a nice click when you try to switch between beams. also if you hold the stalk back both dip and main beam should come on together.

on the flasher switch you have 4 wires:
yellow - dip beam power
white - main beam power
red/yellow - permanent live
white/black - power from headlight switch

unplug this and check you have 12v at the red/yellow. if you do loop a wire between the red/yellow and yellow the dipped beam should come on. if not, you have a problem with the yellow wire somewhere in the dash loom, bad fuses, bad fusebox, or wiring fault in the headlight loom for both sides. or a mixture of all of them in the worst case

last of all the headlights are not powered by the load reduction relay, the black/yellow wire 'X' on the headlight switch is powered directly by the ignition switch. the relay powers the blower motor, wipers and various other high load electrics so if any of those things works the relay is ok

rubjonny said

ok so first of all the grey/yellow wire you found is the power for the fog light switch, its in M plug if you font have front fogs. if you do have front fogs you connect it with the male spade wire of the same colour, and fit a 53 relay to slot 7 on the fusebox. you can do this even if you dont have front fogs but no real need.

if your main beam works fine then there is nothing wrong with headlight switch or wiring to it, as both dip and main beam are fed by the same pin '56' with the white/black wire. This wire goes off to the flasher/beam select switch in the wiper stalk and the indicator stalk has a little hook in the base of it which clips onto it.

first thing is make sure the hook is clipped on properly, you should feel the flasher switch make a nice click when you try to switch between beams. also if you hold the stalk back both dip and main beam should come on together.

on the flasher switch you have 4 wires:
yellow - dip beam power
white - main beam power
red/yellow - permanent live
white/black - power from headlight switch

unplug this and check you have 12v at the red/yellow. if you do loop a wire between the red/yellow and yellow the dipped beam should come on. if not, you have a problem with the yellow wire somewhere in the dash loom, bad fuses, bad fusebox, or wiring fault in the headlight loom for both sides. or a mixture of all of them in the worst case last of all the headlights are not powered by the load reduction relay, the black/yellow wire 'X' on the headlight switch is powered directly by the ignition switch. the relay powers the blower motor, wipers and various other high load electrics so if any of those things works the relay is ok

Thanks Pal will report back later with my results….fingers crossed' Ive also found a new  light switch so can eliminate that.

well as you all know the electrics can be a real pain and its proving that way for me' I seem to start one job and be plagued with many others throughout the journey, I've decided to take the fascia off the steering cowel and the clocks….so I can see the cables at the rear' well its a right mess so I need to  try and make good these cables before looking at the headlights' hope you guys are ready for this      

Firstly i would like to double check the rear heater switch as these wires look like they have suffered from burnout in the past.

On the wiring diagram I have there seems to be a cable missing and what makes it difficult is the numbers on the back of the switch don't check up as to the diagram.
the cable that's missing is grey and blue  there is a grey and blue connected to the fog light switch it runs to the back of loom' take a look at the picture circled in green.

whats your thoughts ?

58b is illumination grey/blue, 31 brown illumination earth. the other 2 spades are screen heater power in and out, you can wire them either way round it makes no difference

you might find the pins on the plug itself are numbered though

the bodged wire on your headlight switch is the illumination wire off to the dash, common for it to burn out on older MK1 as its not fused. people bodge up the radio and allow the illumination wire to short to ground, poof up goes dash illumination wiring

Over here, on this side of the pond what gets folks that don't have schematics in to trouble is that they assume that the Black wires are Ground, which the "Merican" industry commonly uses.  So when they go in to re-wire or add a new head unit,  They get Smoke city…

I personally like the Brown is Ground, as it makes more logical sense, but then again in Illinois the earth is a good Black rich color..

So I suspect with that logic here in Georgia we have a nice rich red Clay, so red should be ground.

On my Cabbies (92, and 93) I used the Metra (sp) interconnect harness that you plugged in to your OEM cables, and then heat shrink and soldered to your head units take offs.  Until I am satisfied that the illumination for the display is inbuilt or needs the Blue/gray or Gray/blue . the lines are so small….. I usually leave it disconnected,,,then I either bend it back and heat shrink to avoid the dreaded short, or solder and heat shrink as needed.

rubjonny said

58b is illumination grey/blue, 31 brown illumination earth. the other 2 spades are screen heater power in and out, you can wire them either way round it makes no difference

you might find the pins on the plug itself are numbered though

the bodged wire on your headlight switch is the illumination wire off to the dash, common for it to burn out on older MK1 as its not fused. people bodge up the radio and allow the illumination wire to short to ground, poof up goes dash illumination wiring

Theres a grey/blue running to the  fog light switch can I piggy back off that so I have all connections for the heater switch ?

yep sure can, or any nearby grey/blue wire. they're usually all daisy chained off each other anyway

rubjonny said

yep sure can, or any nearby grey/blue wire. they're usually all daisy chained off each other anyway

thanks, Pal just to clarify the original grey/blue wire looked like it burned out in the past' why would this be will it be ok to re connect don't want to make things worse

as I say if someone bodges the radio the loom shorts out, as up till around 1987 the illumination feed was unfused. the illumnation wire is the dodgy solder job on your headlight switch.

if any of the wire looks damaged just strip it out and replace, and I'd put a fuse inline with the light switch wire then it'll never happen again

I'm with you the red wire should of been grey/blue' I guess I should be looking at the radio wiring to check all is correct

yep, chase all of the grey/blue wires end to end ideally as where there is some burnt bits you might have some more hidden away elsewhere. also its possible they might have taken out other wires near by as well so do your best to inspect as much as possible

rubjonny said

yep, chase all of the grey/blue wires end to end ideally as where there is some burnt bits you might have some more hidden away elsewhere. also its possible they might have taken out other wires near by as well so do your best to inspect as much as possible

where do they go back to? wheres the best place to add a fuse pal

its linked to dash switches, radio, cluster, heater panel, ciggy lighter and back to fusebox

thanks, pal I think I'm all about sorted for the demister and illumination wire' Now moving on to the fog light switch

Take a look at the picture below the blue wire has been soldered onto the brown under the steering column
what a bodge' have the right wiring diagram pal as I cant find the correct cables

ok so the yellow wire they bodged there is the dipped beam power, cut that garbage off and rip out the green wire bodged into it. fix the yellow wire properly, the connector housing takes 6.3mm latched female spades so easy to get hold of if the bit of brown wire in the plug is too far gone to use.

cut other end of the green wire off the fog switch grey/yellow, then find the grey/yellow wire back to fusebox which was cut off and re-join to switch, thats the spade you found earlier.

blue wire spliced into the black/yellow for heater switch doesnt look the best, could probably do with repair too. ideally get a proper mk1 plug housing and crimp new latched spades on all the wires to its back to oem.

rubjonny said

ok so the yellow wire they bodged there is the dipped beam power, cut that garbage off and rip out the green wire bodged into it. fix the yellow wire properly, the connector housing takes 6.3mm latched female spades so easy to get hold of if the bit of brown wire in the plug is too far gone to use.

cut other end of the green wire off the fog switch grey/yellow, then find the grey/yellow wire back to fusebox which was cut off and re-join to switch, thats the spade you found earlier.

blue wire spliced into the black/yellow for heater switch doesnt look the best, could probably do with repair too. ideally get a proper mk1 plug housing and crimp new latched spades on all the wires to its back to oem.

ok so to clarify I'm talking about the yellow-green brown under the steering wheel……….. if I cut the green off I will be trying to find the yellow and grey cable that's been cut from behind the fusebox.  where is the yellow cable connected to and why isnt it brown' sorry for being anal

The yellow and grey cable was connected to the small bulb in the ashtray ????

in the first picture, you have the yellow dipped beam wire to flasher switch. its been cut and had a brown wire spliced to the end which is going to the switch and a green wire tapped into it which looks to be tapped over to the fog light switch grey/yellow. I assume this has been done in the past because the grey/yellow wire spade you found earlier came out of plug M, and fog switch had no power. whoever bodged all this up obviously couldn't figure that out and instead spliced straight to dipped beam feed poorly.

so remove the green wire spliced into the yellow & brown, and also de-pin the brown from the plug. make a better repair if the brown is too far gone to work with

for the fog light switch cut off the green from the grey white, and try to find the other half of the grey/yellow they cut off  and re-join so its back to factory.

cheers pal think its all in order now' I decided to remove all the plugs from the steering rack and repair the terrible repairs to the  red/black ignition wire' and the earth take a look at the pictures……… Can I test these now without installing the speedo cluster

you mean the ignition switch wiring?

black is ignition live to fusebox and also cluster, red/black is starter cranking live, red is live, black/yellow is x-relief live which is on with ignition and dead while cranking, grey if there is parking lights, live ignition off

for the cluster plug if you check between the red and brown you should see permanent live, black to brown ignition live