Cluster Lights Not Working

[davej]

Bought the car with non-working gauge lights. Was trying to get the horn working again (unrelated problem) and figured, screw it, let me see what's up with the dash. I got it out and checked the bulbs. They all looked ok, but thinking back to grandma's Christmas lights, thought if one was bad maybe they'd all be out, so replaced them all. No luck.


Little more detail, it only seems to be the back light for the speedometer/tach/h2o/gas that are out. Blinker/high beam indicator/etc light up when called. Dimmer works properly for the lights behind the heater sliders.

Read thru some other posts about checking dimmers, and how to get the light knob off. (Very helpful BTW) and found this behind the light knob




Clearly something bad happened in its life. That's the yellow/white stripe wire that's melted/corroded but according to the wiring diagram it goes to the hazard switch , and the hazards worked fine. I cleaned all the contacts as best I could but still no luck. On the plus side no new lights were out when I got it back together.

Any thoughts on what to try next?
Oh there are no fogs, just a dummy switch on the dash.

Thanks!

Edited August 21, 2013 by davej

[Mike Self]

From your pictures, it appears that your headlight switch is toast.  Something in its past life overloaded the switch, and it melted internally.  The dash lights (those that illuminate the instruments) are controlled by a rheostat that's part of the headlight switch.  They will go bad and either make the lights work  intermittently or not at al.  You'll need a replacement headlight switch (someone on the board most likely has a good used one), and you'll have to repair that burned/melted wire--at least the last few inches--and the insulated terminal on its end. 

 

Hopefully that'll get you back in business.  FYI, all US cars have dummy fog light switches.  They were options on Euro cars, but not on US versions.  You can install fog lights and a functioning switch there and wire 'em up to work.

 

cheers

mike

[davej]

awesome, thanks for the tip Mike! off to the classifieds. =)

[Simeon]

Did a PO run higher wattage bulbs or driving lights in parallel with the headlights?

Check you have none of these or add relays.

Can't tell if the damage is all external to the switch from the photos

[jessiejake02]

I had the same problem on my 75 02. #7 fuse kept blowing up. The right side parking lights were out and so is the instrumentation illumination. I saw the same burnt wire on the switch wire harness. At first i thought it was the Switch, but I tried 5 different good known switch, and still didn't solve the issue. I haven't had any luck tracing the short circuit.

[jgerock]

Did a PO run higher wattage bulbs or driving lights in parallel with the headlights?

Check you have none of these or add relays.

Can't tell if the damage is all external to the switch from the photos

+1 on this.  Be careful with stock headlight switches on early cars. Cheap insurance adding a set of relays for high and low beams.

 

Edit - your dash surround may indicate either you have a Square light car (relays standard) or the dash was swapped in your car. Please advise what year your car is.

Edited August 22, 2013 by jgerock

[davej]

Did a PO run higher wattage bulbs or driving lights in parallel with the headlights?

Check you have none of these or add relays.

Can't tell if the damage is all external to the switch from the photos

not sure, i'll have to check tonight. thanks!

 

 

I had the same problem on my 75 02. #7 fuse kept blowing up. The right side parking lights were out and so is the instrumentation illumination. I saw the same burnt wire on the switch wire harness. At first i thought it was the Switch, but I tried 5 different good known switch, and still didn't solve the issue. I haven't had any luck tracing the short circuit.

 

That's not good to hear =) hope you find it!

 

+1 on this.  Be careful with stock headlight switches on early cars. Cheap insurance adding a set of relays for high and low beams.

 

Edit - your dash surround may indicate either you have a Square light car (relays standard) or the dash was swapped in your car. Please advise what year your car is.

 

showing my newb side here, but what's a square light car? do you mean the rear end as opposed to the earlier models with round tail lights? I have a 76, square light rear, but if it's something different you're talking about than i might need some more direction.

thanks!

Edited August 22, 2013 by davej

[ecpreston]

yup, he's talking about the rear lights, yours is a square light car. As opposed to a round-eye.