Instrument cluster

The lights on my instrument cluster went out the other day, after having worked fine. The fues they are on goes when I switch the headlights on, I replaced it with a 30 amp fuse (should be 15 amp) for the taillights to work but the instrument cluster still does not work. I have replaced the dimmer unit with one I know works but nothing. Now what do I do?

George

'87 745 GLE Turbo Diesel Intercooler
'88 745 Turbo Intercooler

Hey George, Long time no speak...


Are you sure the Dimmer Worked before installing, and is it of the same type as the one you removed??

Mine had this problem (760 GLE) when I bought it, so I stripped it cleaned it and Guess what ... It worked!! Slider works etc So it's Just a thought to Double check the Dimmer, Failing this can you change the instrument pods over with one that's working?? That way you eliminate a possible fault on the printed circuit on the pod.

Let me Know How you get on.

Regards
Dave M

This problem is getting very complicated. The instrument cluster is not working because the fuse is blown and the fuse goes every time I switch on the headlights. The fuse for the day time running lights goes when I switch on the ignition, so clearly a fault somewhere in the light circuit. At this moment I have no brake lights, no back up lights and no instrument cluster lights. This car is going in to the electrical specialist.

George

'87 745 GLE Turbo Diesel Intercooler
'88 745 Turbo Intercooler

Hi George,

What about the "Old dry joints syndrom" on the Lighting relay?? Just a thought... Peter fixed mine with that, on the "Fog light" issue and Guss what I've Got them back again:-) !!

Though it was worth one last try:-(


Regards
Dave M

I tried a new relay, made no difference. Anyway, I was told by Volvo that the relay for the headlight does not do anything to the dashboard lights. I have now sorted everything else so I have reverse lights (switch in gearbox)and brake lights (fuse) but no dashboard lights. This is driving me nuts. I had come to the conclusion that something behind the dashboard or even in the fuse box shorted the dashboard lights so causing the fuse to blow (and it blows the second you switch the light on, this is fuse 21). Now, I do not know. It says on my ashtray that the fuse also controls rh tail lights (they work fine) and power roof hatch (this works fine too). And today came the weirdest thing ever. For a few seconds (driving over a small bumb) the dashboard ligths came on (with headlights switched off and no fuse either in day running light fuse holder or no 21). WHAT AM I TO DO!!!!!!!!!!!!

George


'87 745 GLE Turbo Diesel Intercooler
'88 745 Turbo Intercooler

[pettaw]

sounds like a dry joint either on the printed circiut board or on the connector to the dash. firstly try cleaning the connections to the dash by unplugging them and then putting Ultrasolv or other electrical solvent cleaner into it and then winkle in and out a few times.

Andy

This is possible but still, not only the instrument cluster lights go off (or on as may be!!) but all the dashboard lights for the switches and for the heater control unit. Also, how the devil can the lights come on when the headlight switch is on the off position, no fuse for the daylight running light circuit and not even a fuse for the dashboard lights?

George

'87 745 GLE Turbo Diesel Intercooler
'88 745 Turbo Intercooler

[Peter Milnes]

Apart from a short circuit occuring in the wiring (faulty insulation in the loom could be a cause) the only answer appears to be that the headlight switch has developed a short circuit inside it and needs replacing. If they are the same type try swapping over for the other car's switch.

All the best, Peter.

Nope, got a functional switch today and it did not help. I have no idea what to do now.

George

'87 745 GLE Turbo Diesel Intercooler
'88 745 Turbo Intercooler

[pettaw]

sounds like the wiring loom itself may be dodgy then if its the older type which if I remember correctly is pre 1989? The insulation crumbles away and leads to weird short circuits. Peter M will be able to give a more complete answer.

Andy