[79 Phoenix]

I have a 79 Phoenix and having an electrical problem. Headlighhts and all external lights work including the right turn signal (but not the left).

Symptoms are: 1) Gen (alt) light works 2) Windshield wiper switch light works (and dims with headlight switch rehostat) 3) right turn signal indicator light works 4) But none of the other instrument panel lights work.

I have changed all the bulbs. I have cleaned all the contacts and tightened the brass sockets the bulbs press into. I have replaced a few of the sockets with new ones. I have changed the fuse. (even though it didn't look blown)

I do notice that a few of the copper printed circuit contacts around the light sockets are loose but they tighten down when I screw socket into place. Other than that I don't see any obvious problem with the printed circuit.

Still it doesn't work. Does anyone have any suggestions as to what the problem may be?

[nkowi]

If you haven't already, consider posting this in the Electrical section. Lots of help there.

I know you said all the external lights work, but I gotta ask anyway; do the taillights work? Not just the brake lights and not just the blinkers or hazards, but when the only activated switch is the one for the headlights, do the taillights come on?

[goatwgn]

If the taillights are out then likely a blown fuse. If not it possibly could be the rheostst (dimmer) in the headlight switch.

[Cameano]

I recently had to repair my printed circuit on my dash. It started with changing the right turn signal bulb, and ripping the printed circuit next to it when I put it back in. When I went to remove the harness plug, a bunch of the circuits pulled away from the board, and got screwed up. I ended up cutting pieces of .020" copper sheet to the shapes needed, and silver soldering the board back together, rather than wait 2 weeks for a new pc board. Works great now, everything working like it should.

[newtoponcho]

This sounds to me like you are missing or have a bad ground from the cluster to the dash or steering column support or near the drivers side kick panel area (all models are different). Do you have a wiring shematic for your car? A manual may show you a location for this ground. It could be as simple as a loose or corroded ground (bolt or screw and wire with an eyelet or more than 1 wire). My lemans had a similar condition, but it uses a metal strap from the cluster to the dash for grounding. HTH.
Nick

[79 Phoenix]

I didn't disconect a ground...Maybe that explains why it doesn't work. I wonder if I could put my own ground on ...If it already has a ground it wouldn't hurt anything. But if it's not grounded it could solve the problem. Do you know where I should attach a ground? I don't have a Phoenix manual but do have a Chilton's for Novas. I wonder where I could get a wiring diagram for the Phoenix?

[newtoponcho]

I'm not sure where you to get a shematic for your car,(may have to buy a factory manual). I would investigate the area's that I suggest for a possible ground connection. Follow the cluster harness down and see where the breakout points are, looking for black wires coming out.These will be your grounds.Running your own ground would work, you just need to know where it is on the connector (again wiring schematic) and how many there are.
Good luck with your search.Let us know what you find.
Nick

[Cameano]

The problem I had with mine initially was the ground circuit on the printed circuit. It follows around to every bulb on the board at some point. If the pc is loose, it might be broken.

I looked at some examples on various sites of the new pc board, and repaired mine with the info.

[79 Phoenix]

Thanks--I will look into everybod's advice. I really appreciate it!

[79 Phoenix]

So far I have found two ground wires --one black and one dark brown. They both attach to the printed circuit and broke out of the harness under the dash.I thoroughly sanded the screws, eyelets and dash to make sure there was good contact and then tightened really well. I also switched the fuse again. Still no lights.

Also, I double checked and do have tail lights, parking lights, headlights, brake lights, four ways and right turn signal only.

2 or 3 of the copper circuits that encircle the light socket holes on the printed circuit are loose but tighten down when socket is screwed in.

I'll update when I've had time to look further.

[74Grandville]

Originally Posted by goatwgn

If the taillights are out then likely a blown fuse. If not it possibly could be the rheostst (dimmer) in the headlight switch.

X2

replace your Headlight/dimmer switch.

[79 Phoenix]

Some more observations: Headlight dimmer switch works and the indicater light for high beams also works.

Also, the left turn signal indicator light does come on but does not blink. Flasher unit is new. Could this indicate a ground problem with the parking light or tailight socket?

[derekdag1]

Kim

That's odd about that turn signal. If the light comes on, then the circuit is obviously complete (meaning not a ground issue with it). Does your '79 have a seperate flash module for the left blinker by chance? I know my '74 uses one module for the blinkers, and one for the emergency flashers. I just don't know if something changed between the '68-'74 and '75-'79 body styles.... I schematic would be VERY helpful there.

That doesn't eliminate your flash module as being the culprit. Try swapping it with the emergency flasher module and see if you get any different results with it. If so, great. If not, then.... The inside of that flash module has a piece of bifurcated (or something like that) metal in that causes the opening and closing of the circuit. It is basically two different metals that are melded together into a strip, and these two different metals react differently when heated (aka have current pushed through them). One expands more and causes the strip to curve as it has current pushed through it, therefore opening the circuit (and the light goes out). After it cools for a sec, it returns to normal and closes the circuit again (and the light comes on). to me, it sounds like that "left blink" circuit may not be pushing enough amperage to get the strip to heat up and curve for some reason (and will be very tricky to troubleshoot the cause of since it is not blowing a fuse).

The circuit is actually a fairly simple one with only the left blinker switch, the flash module, a fuse, the lights and the wiring. It sounds like you did a good job of inspecting all the lights/sockets, and tried a new flash module. The only other thing that I think may be the issue is the switch. I know what you are thinking--"Say what?" There could be enough resistance through the "left blink" part of the switch to not cause the metal strip to heat up enough to break the circuit. Try taking an ohmeter and measuring the resistance through the left contacts and then through the right contacts and compare the two. If the left contacts value is significantly higher, then the switch could be the issue.

One last idea is the plug the flash module sits in. Check it out and make sure the prongs from the flash module are making solid contact with the plug base. It could be loose one side and causing resistance in the circuit.

Outside of that I am stumped without getting to work on your car directly.... Sorry!

Hope that info helps
Derek

[rohrt]

This sounds very familar to me. I had a very similar issue with my 68 bird. I had new wireing everywhere and new printed circuit board but since I had painted everything I to chase bad grounds in the gauge cluster and had a bad flasher unit too.

I tested the flasher unit with alegator clip leads and a few 1196 bulbs right on the car battery. The current from two bulbs and both elements was not enough to trip the blinker. Only a dead short on the blinker modual would get it working.

In the end I mapped out the wires that went to the guage cluster and from the steering wheel blinker switch assembly. I had to pull my gauges out like 5 times to get it all correct. With the wires mapped out I could see if I had the correct power going to the guages and coming from the blinker switch assembly.

Good luck.

[79 Phoenix]

Derek-You were right! There are 2 flasher units. I replaced the second and both 4 ways and blinkers work fine. Thanks!

Like I said earlier, the dimmer switch for the headlights works as does the high beam indicator on the dash. But a wierd thing happens ...

When the headlights are on but high beams are not, the high beam indicator bulb glows ever so slightly ---You can barely tell it's so dim--just barely lights the top of the filaments. The bulb lights up all the way when the high beams put on. The dimmer switch is new (put in by previous owner) The plugs plug together but the plastic clips that hold the plugs together don't fit exactly right. I guess that means it's a generic GM switch or just not the right one. But it works. So I'm not sure what that means.

So as it stands it seems all the lights that should work on the dash do except the lights that illuminate the guages themselves (Gas, Oil, Gen,Temp, Speedometer and Pontiac dummy panel used if there is a clock). So there must be another ground that I haven't found yet that isn't grounding properly.

[mechanickeith]

Kim, it does sound like a bad/poor ground in the instrument panel. Sounds like the dash lamps are grounding through the high beam indicator circuit. Do you have a factory wiring diagrahm??? That would be very helpfull/give locations of grounds, etc, etc.

[ta man]

Run a temporary ground to the cluster and see what happens.

[79 Phoenix]

I FOUND THE PROBLEM! There is a small part of the wiring harness fastened to the back of the light pod and printed circuit. The wires from that connect to various sections of the printed circuit. One black wire I assume is a ground wire attaches to a clip which, in turn, attaches to the printed circuit. I began fiddling with that attachment and got the guage lights to come on although intermittently.

1) The lights came on but were quite dim (amber in color) Are they supposed to be that dim even with the rehostat turned up all the way? Or, is that because there is still a bad ground?

2) What would be the best way to make this connection right? Perhaps take it apart & clean everything but it still appears to be a little loose. Should I solder it? How risky would that be to the printed circuit?

PS-When I got the guage lights working (dimly) I noticed the left turn signal seemed to blink just a little slower.

[79 Phoenix]

As it turned out, one of the clips that fasten the wires onto the printed circuit was not making contact because the clip had indented the copper on the printed circuit too much. I cleaned all the contact points and tightened the clip so it made contact. Then all the lights worked.