Dash lights dont work

I’m loosing my mind with this one so any help is welcome:
Car is ’71 xr7. It came to me as a total wreck. Lights were almost ok, but dash lights didn’t work. I took whole dash out restored it and installed new cirquit board. Old one was burned and partly melted.
Then I took head light switch tore it apart and it was badly corroded from inside, but I did see connections from inside. I replaced that with the new one that was litlle different, but new. I cleaned fuse box from rust and new fuses went in.
After week playing with the electric schematics and hard thinking I finaly made it and all lights worked! I had to take that (don’t know the english word) plastic piece from cars side of the switch and did just straight connections to headlight switch.

Well week ago I was starting to brake in the engine and headlights just vanished! Damn. This time I took that damage to my bank account and ordered new switch. Tonight I opened schematics again and made clear drawing about what wire goes where. I even translated it to finnish to get it right. (Doing that I found that reason for headlight going of were propably bad long beam switch!) Anyway I rewired that cars side plastic thing (connector maybe?) and the results were exactly where I started from! No lights in the cluster, but courtesy lights work and dimmer works with them wery well. Brakinglight might have some issues too, but I wasn’t interested anymoore to find those out.

Does anyone have ideas? I think I’ve read the whole internet already. How many wires and what colours goes in what plug? Do I even have right pics or has some previous owner mad his own connections that I don’t know about. There were some with two wires going in the same plug. Pic would be nice :slight_smile:

My 67’s dash lights also have an issue of not illuminating. Do all the other lights work that work off the switch for the headlights, parking lights, tail lights, courtesy lights work? If so, you are getting potential to the switch. The issue I found in my case was corrosion of the rheostat spring, and subsequent connecting terminals that make up the dash light circuit. A continuity test with a simple probe can help determine if this is the case by checking each point of contact starting from the fuse box to switch connection and then working through the circuit. I disassembled the rheostat portion of the switch, let the plastic components to soak in a 1:4 solution of Simple Green and hot water for 30 minutes while having the spring in jelled phosphoric acid for around 5 minutes. The connection terminals also were coated with phosphoric acid for the same duration before being rinsed off with hot water being careful not to get any water inside the switch housing. After cleaned and dry the rheostat was assembled and again tested with a continuity light. At first no outcome was had. Through minor adjustments I was able to get the rheostat functioning properly. Tomorrow the light switch is going back in to see if that effort paid off. While there is 4 years difference in our models, I’m willing to guess that this may be the causal issue for you as well.

Only gauge cIuster lights are dark. It is not the switch or the electric connectors. Switch is brand new and connectors I cleaned earlier. Actually I didn’t check the fuse last night😅 On the other hand I dont think there is separate fuse only for gauges?

No fuse for gauges. Gauge cluster lights are also used for heater, ignition lamps, wiper switch lamps. If those work, then the problem is in the dash cluster connector or circuit card.

I just spent few hours working with that. I did get lights on with the jump wire. I only kept it on few seconds for not burn anything. I also asked my electrician friend to come by and check my connections. He agreed with me that switch is good, all the wires goes where they suppose to go in the switch and connector for the switch.

So connections are good, cirquit board is good, switch is good. There are right number of wires. So it’s like where it is supposed to be two brown, there are. It just dont work!! What am I missing?

When I have time I try to get wires straight from battery to see what it does. I’m really starting to be out of ideas.

Where was the jump wire connected on both ends to make dash lights work?

Sorry, I forgot the main point! Hard week behind I guess…
It was between brown and yellow. I’ll check again tomorrow. Almost 9.30pm here. Yellow I’m sure off. I think the yellow is main power wire, so my idea was that I ”by pass” the switch (hard to explain) and take direct route to cauges.

Did you bypass the fuse box? Did I read you correctly that all other dash lamp circuit lamps work but not the dash cluster one?

I’ve found that some multiwire OEM splices are flakey. One wire is incoming signal, then gets split off into multiple wires and directions. By pulling on the flakey wire from the OEM splice, I can get continuity down to below an ohm. This is very hard to do in the car, when you don’t know where the OEM splice is and what direction to yank the wire. If you bypassed the OEM splice, then that splice may be the issue. When all else fails, you can cut the wire going to the dash cluster connector and splice it into another blue/red dash lamp wire that works. Protect the open end, of course. This is a final solution when all else fails. When I have a harness on my bench that has a bad OEM splice, I cut all the wires at the splice and manually reconnect them with butt splices: 2 wires into each end. It’s a mess, but sometimes it is what you have to do to get things to work.

Ok, I had bit more time with the dash. I actually did jumper wire with the switch that was not right one! Then jumper was definetly from yellow to brown at the switch connector, and cauge lights did work! We touched fuse box only to sand of the rust. So it was after the fuse box. I misunderstood what he did under the dash… sorry guys😟 (I’m embareased) so cauge lights worked only with the wrong switch, with jumper from yellow to brown, after the fuse box.

With the right switch cauge lights never worked. With or without jumper. Now there is right switch attached and situation is this:
Cauge cluster has high beam marker working, right hand indicator light works. Oilpressure and amp lights works, so I guess those are neares working lights to get electricity to cauge cluster if it comes to that. I’ve never seen cauge cluster lights completely working so I’m not sure how those are supposed to work.

Tachometer itself works. Speedometer I don’t know it has new wire so it should work. Fuel cauge has faulty sender unit…

Has anyone took of the cirquit board and rewire whole thing? I’m really not so keen to do it, but if anything else don’t work…

That’s the old cirquit board that I replaced with the new one. The new (was old too) had also couple of those coppers that had come of the plastic.

Yes, I manufacture a hard-wired harness that replaces the circuit card and the dash cluster connector with a quick-disconnect molex connector.

If some of the lamps work (e.g. amp light, oil pressure light), then you’re getting signal to some of the dash. I’d examine the circuit card carefully for any cuts. I’m presuming you’re not using LED’s, as those are usually polarized and need to be properly oriented.

It’s been some time after last message. Having trouble with Clevos ignition now, but getting closer :sweat_smile:
No LED in my car. I tried that other switch that is from some other car and got lights again! Jumper wire from yellow to brown. Just measuring electrics whats happenig in each position and connected that way. Not good enough for me. I really want those to be right. Forgot to take pick from those connections though. What a pain in the b*t!