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Discussion Starter · #1 ·
This is on my '71 malibu:

After working on it for 2 hours I had to take a break. Here's the problem - the lights that light up the insturment panel do not work.

I checked all of the bulbs. The strip that they connect to appears to be o.k. The fuse is good. I am getting electric to the headlight switch (I checked at the contact spring) I can turn the dome lamp on and off. The tail lights, and brake lights work. I am not getting power to the gray wire that goes to the light bulb socket. I also noticed today that the right turn signal light in the dash stays on when the ignition is on, and the right signal won't work, but the left does. The fuel gauge reads past full, even though it's bone dry.

Where do I go from here? I have a bad feeling I'm going to have to pull the damn dashboard out.


I'm lost - electrical sucks sometimes!

[This message has been edited by AdamLym (edited 03-01-2001).]
 

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Could that gray wire have been cut somewhere along the line, before it reaches the instrument cluster?

Maybe somebody hooked something up, that required a "light" source (i.e. maybe some kinds of radios, instruments, etc.) and either did not splice it correctly or just cut it?

Have you checked for power after the light switch? (i.e. perhaps the switch is bad?)

Good luck on that...you're right, what a PITA electrical can be...

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I work to live, but make money for fun...when am I gonna start having fun?

John's 383 Malibu

[This message has been edited by John_R (edited 03-01-2001).]
 

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I think that your gas gauge situation is not related to the panel lamps. If your tails and dome lamp work, then you have power to the same circuit that powers the panel lamps. Try a jumper from +12v to the positive side of the panel lamp strip and see if they go on and can be dimmed properly. That would tell you if the +12v is absent or if the problem is with the ground side which goes to the dimmer.One trick is to use a safety pin to puncture the wire in question (between the lamps and the rest of the car) and measure the voltage on the safety pin. This would allow you to check for voltage or ground along the length of the wire and find any breaks.
 

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Adam
JWagner has got a pretty good thought. Just a couple of things.
1, No need to tear apart the dash. The lamps can be reached by removing the top dash pad and working over the top. If I recall the gray wire is in the left most bulb in the cluster. Should be able to get at it. Maybe a bad socket at that bulb.
2, See if you can spot the original radio power plug. The gray wire also goes there. Any power at the gray wire here?
 

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I had a exactly the same problem many years ago. Turns out I had lost the ground after having the dash dropped down to replace a bulb. Just for grins, try this: Turn on your dome light by rotating the headlight switch
and then open the door. This will activate TWO switches to the dome light. On my 68 when I did this it somehow created a ground for the circuit and everything immediately went back to working normal. Shut the door and the problem was back. Sounds crazy, I know! That doesn't solve your problem, but at least it will confirm what the problem is. Hope you'll let me know if this helps.

If that's the problem, someone on this site will be able to tell you how to get "grounded".

[This message has been edited by Barista (edited 03-01-2001).]
 

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Discussion Starter · #6 ·
John, I'm glad you mentioned that grey wire at the radio (even though I don't have a radio) - I was hooking up my gauge cluster lights, where I had a ground, a yellow, and a grey. The grey (at the radio) has NO power to it - hmmm, so what would this mean?

I am going to try a 'jumper' wire tomorrow

How do you take out the headlight switch?

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1971 Chevelle Malibu - 406 sbc TH350

Pictures of my '71 before I got it home
Pics of my '71 after I got it home
Picture of my 406 c.i. small block
Pictures of the frame, firewall and interior (in progress)
NEW UPDATED PICTURES (1/04/00)
 

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Here's what we do know:
1) There is power to your light switch.
2) The dome light works.

Questions:
1) Is the output to the cluster lights, via the headlight switch dimmer, working?
2) Is there a bad ground?

Some things to try:

1) Pull out one of the cluster sockets and remove the lamp. Measure the voltage between the gray wire to body frame (not the dash). If you have power, then your problem is with the ground connection to the dash. If not, go to step 2).

2) Locate the output at the light switch that goes to the cluster lights. Check for output voltage. Depending on the position of the dimmer, you should get between 0 and 12 volts. Turn the know back and forth to check. For you ground lead, connect it to some point on the frame (not the dash). If you have power, then your problem is a break somewhere between the switch and the cluster lights. If not, the dimmer output of the switch is faulty and you'll need to replace the switch.

Good luck,

Randy


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Randy Hammett
69 SS Silver Bullet
TC #985
ACES #4252
 

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Gas gauge reading past full and lights not working tell me you have a ground missing to the metal gauge panel. Take a jumper wire and tie one end to a good ground, with the other end to the metal gauge panel (loosen a screw and insert bare wire around it, then tighten down).
Make sure they are good grounds. Meaning non-painted and clean brushed metal. These cars are 30+ years old and the metal can have invisible coatings that insulate what you think is a ground.

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Steve Strasemeier (70SS 396, Fathom Blue/White Stripes)
My 70SS
 

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Adam
The switch comes out by pulling the knob all the way out to the on position. If you reach underneath the switch body you will feel/see the shaft release. This is a button about 1/4 inch in diameter that feels like it is floating on a spring. Push this in and slowly pull and turn the shaft. The knob and shaft should come out together.
On your 71 the gray wire only goes to 2 places. If you don't have power to the radio plug, you have the right idea to chase it back. From those two places the wire heads to the fuse block. Not what I would take apart yet.
After you remove the headlight switch, the wires out of the switch are the tan and light green. These go down to the fuse block from the dimmer switch. The line that feeds the dimmer switch is the light blue one.
The other guys are right. You have more than one problem but nothing big, only work.
John
 

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Discussion Starter · #10 ·
I installed a new headlight switch tonight and it didn't make a bit of difference. I tried taking a ground from the chassis to the metal part of the dash (by the printed circuit)...didn't work I have a new occurance though, when I twist the knob of the headlamp switch the dome light goes on, but when I twist it the opposite way the tail lights, and side marker lights go on
I checked power at the headlight switch connector - I only get my voltage tester to light up on the red wire and the orange wire - none of the others work. Where do I go from here? How can I/should I trace the wires?

How can I check to make sure the light sockets are good, and the printed circuit works?

You know, a 6'5" frame sure gets cramped working under this dash!

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1971 Chevelle Malibu - 406 sbc TH350

Pictures of my '71 before I got it home
Pics of my '71 after I got it home
Picture of my 406 c.i. small block
Pictures of the frame, firewall and interior (in progress)
NEW UPDATED PICTURES (1/04/00)
 
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