86 camaro. when I turn the lights on the Tach, battery and temp guages go down like the enigne is off. when the lights are off it all works just fine. Anyone have anyideas.

Try the dimmer switch, there should be either be a **** or a dial that will change the brightness of the gauges.

What you should do, is check the fuses for the instrument panel and lights. If they're only going out when the lights are on, then it's prolly just a bad fuse. That's about the best advice I can give on that.

I had a similar problem.

When my lights went on, my dash lights would go out (about 75% of the time). It ended up being a bad headlight switch.

Pull your cluster out and check for broken PC traces on the back of the cluster. Sometimes they break around the light bulb sockets. The easiest way to fix them is to solder a new section of wire onto a couple of bare spots to 'jump' the broken line. You can use the soldering iron to 'scrape' away some of the plastic covering to expose the trace if no bare spots are handy.

Pete

You know what, this is hilarious. I was just about to start this topic myself! Oddly enough, this is an 86 too. I have however gone into this problem more deeply. I bought a brand new headlight switch today and installed it. That, sadly enough, was not the solution. Now, i did some troubleshooting, in this fridgid weather. I find that when i drop the dimmer switch till the dash lights are out, all returns to normal, all the fuses are good, and the blinkers, lights and brake lights are working perfect. Now i have to trace out a diagram to find out why, but when i pull the fuse for Tail (tailights????) everything returns to normal. Any wiring genuses with input, i'll give you my 1st born, if i ever have one.

This is exactly whats wrong with my car. Its not that the lights go out on the dash, its that the gagues stop working. and when i turn the dimmer to off where the dash lights go out the gagues come back on. anyone know or have a ideas as to why this happens?

Also I have another problem with the rear right turn blinker. When I turn on the blinker only the front light comes on contuious and the back one doesnt do anything. I have changed the bulbs and the plug in the back only has 2 wires one in the bottem and one in the side. should this be like that??, and when i went to the store for a new plug they all had 3 wire connectors. I woulnt know how to make it work.

Guess no one knows.

Guys I had this very same question answered for me a while back, hang in there and I'll find the thread for you guys when I get home from work. The comment about the broken connection on the guage board is correct.

I did a lot of poring over diagrams before I found the problem. All worked fine when the dash lights were off....turn them on, even the slightest bit, and my right-hand blinker indicator lit up, the tach just hovered and would move up and down by varying the brightness, and I *think* the oil pressure guage went to zero (been so long I forget if was affected or not). Just happened on it one day when I had the cluster out to change some bulbs.

Pete

I had the same exact problem on my 84 Z-28.
It is the printed circuit board behind the gauge cluster.
Usually the circuit gets corroded and breaks right near that left
turn signal light on the cluster.
Like it was said befor if you carefully solder a piece of wire in there
that will fox it, or you can just replace the cluster if you find one in good shape.
If you don't have a 145MPH speedo, it's not a bad time to start looking for a cluster with one in it.

Also when the search becomes available again, search for
tach jumps with turn signal
by canadian beast.

I don't know how to attach a thread, but I know thats the thread I had my big disscusion about this problem in.

Also whats wrong with my right rear turn signal??? when i turn it on the front one just stays on and the light in the dash doesnt blink just stays on too like a bulb is out. i checked the connector in the rear and it has 2 wires one on the bottom and one in the side. anyone who has this same connector please look and tell me if thats right about 2 wires. Because all the other connectors in the car have 3 2 on bottom and 1 on side. But there is no extra wire just hanging around and i tried to trace back the wire loom to see if it had broken off far in there and still cant find anything. so im not sure how to fix this right blinker problem... ???

AFAIK, there are just two wires to the TS socket...on the righthand side they will be black and dark green. Sounds to me like a blown bulb.

Pete

i put new bulbs in and tested them and the old ones and new ones work just fine. Im still not sure how to make the right turn signal work. Does anyone know what could be wrong with this thing. Also the Tach doesnt work.

I havent pulled the dash apart because I think it has something to do with the 2 wire 3 wire thing.
On the bottom of the bulb there is 2 things that connect power, BUT if only one of those and the brass side of the bulb can make it work than maybe the 2 wire isnt a problem but since there is one connector conected im not sure

does anyone think that the right rear turn singnal could be because of the wrong bulb? what is in there now is a 2057 but i head thats for bright and dim and what should be there is a bulb for only bright??? could this be it?

hit the turn signal switch, now go to the bulb and twist it a little or slightly push it w/in the socket. This happened to me on a 91. I thought it was the bulb first also. turns out bad connection w/in socket.

thats not it ... there is no voltge on the wire period. the right front one works and the left side blinks just fine but the right rear doesnt work.

Ok, im at a loss with your blinker question, but, I took the whole guage cluster out and tested every bulb, and copper pathway that should have continuity. Everything was fine. Now, i pulled the fuse that says TAIL, (Tailights) and it all went away. I had no rear tights, but the problem is in that circuit. I just need to take the time and sit down to trace out the circuit for that fuse. Anyone with more info on this, jump on in.

im getting no power at the back right light at all and sometimes this dead gauge-lights on problem works just fine and the blinker still doesnt work. and then most of the time when the lights are on the gauges dont work. i just pulled the face plate off the gauges and just got to find out whats still holding it in. I havent pulled the panel out from underneeth yet because i wasnt thinking that anything under there is holding the gauges in ??

How do you pull the Gauge cluster out???

Now it sounds like you may have a bad power or most likely the ground wire to the light socket. I had the same problem with my Monte SS it was a ground wire borken. Check all the grounds for the rear lights, and see what you come up with.

there are 2 wires on the right rear turn signal and all the other ones have 3 and the wires are in good shape and one has ground but the other has no positive. still not sure how much i have to do to pull this dash out.

Somewhere those ground wires will meet up with a body panel or something, to ground them to the body. Follow the wires a bit under all the plastic to make sure they are grounded properly. I had to look around a fair bit to find my problem too.

to pull the dash, take off the trim plate, the cluster has 2 7mm (???) nuts that hold it in, they are near the SES and brake warning lites. after that you need to reach under the dash, near the speedometer, you will feel the small tab near the center of the speedo to release the cable. to get the cluster out you need to remove the two nuts holding up the column to drop it. the cluster comes right out

allright fixed the dash lights problem and blinker problem. Thanks., But got another problem with the tach. its not working. well the coil had fallen down by the exaust and melted and shorted out. went and bought a new one and engine runs again. but tach stopped working. if i hook up a wire to the coil and ground with a tach, volts , ohoms meter it tells me the RPM. but i still have no clue why the tach inside isnt working.??/

Curious here, What was the problem with the lights?? What was causing the problem I should ask??

the problem with the dash was the printed board on the back had burned a place out. I just soldered a jumper in place and that works. The problem with the blinker was a wire under the dash was not connected right. all i did was push that back into the place. the RPM stoped before i stared messing with any of this stuff. it stopped when the coil shorted out. have no clue what to look for . any ideas?

anyone?