Parking Lights w/Key Switch

[Its Just Me]

My parking lights and my dash lights all turn on when my key is in the run position. The lights are quite dim and they brighten a bit when I rev the engine. I replaced the light switch to no avail (needed to change it for other reasons though). All the lights work as they should with the key off, but I lose the ability to dim my dash (or turn off the parking & dash lights) when the key is turned on. I do not have LED lights. I have good grounds from the battery to the engine and from the battery to the front fender.

The car was restored previous to me so I have no idea if a wire is crossed or connected wrong, though based on previous issues, nothing would suprise me.

Could it be the key switch?

Where should I start looking.

Thanks

Scott

[Toppless72]

Scott,

 

Do you have an aftermarket radio in the car? If so, the problem could be at the radio hook up. If the radio power wire (20g yellow) is connected to the wire that powers the dial lamp (20g gray) it will reverse feed the whole parking light circuit.

Here is where I would start. With the key on and the headlight switch off, start pulling fuses one by one and see when the lights go off. That will be the circuit to trace down for the problem.

[Its Just Me]

Joe:

I do have an aftermarket radio, but I unhooked it completely and nothing changed.

I'll give your suggestion to pull fuses a try when I can get back to my car.

Thanks for the help.

Scott

[Toppless72]

Scott, Make sure if you disconnected the radio that the gray wire is not making contact with any other wire.

[stangeba]

When I first read this, I thought of a poor or missing ground somewhere. There is a dash (I/P) ground wire that is attached to the parking brake assembly. There is a H/L switch ground. These pictures should point you to their location. Also, didn't we conclude back several months ago that the H/L switch was special for our Monte's and many replacements were missing a strap between two lug on the switch?

Bruce

Dash ground on parking brake

H/L switch ground strap

Original 71 H/L Switch

[Its Just Me]

Toppless72:

I was able to work on the monte a bit last night and pulled fuses out of the fuse block until the parking lights went out. The fuse that killed the parking lights was the one in the "radio" slot of the fuse block. So now I know which circuit is affecting the lights, but what is the next step?

In an earlier post you made reference to a gray 20g wire and a dial lamp. Could you clarify. Is the gray wire you refer to, on the back side of the fuse block, as I don't see any gray wires on the face of the fuse block? What is a dial lamp?

Sorry, I'm not too sharp on electrical issues, but I'm trying to learn.

Bruce: I confirmed that I have both the ground wire connections you refer too, and I did replace the headlight switch, (with your previous assistance, thanks again). The switch needed to be replaced because the dimmer motion was shot and some lugs were loose. I was hoping that the switch replacement would solve this issue...wrong.

Thanks all

Scott

[monte70car]

The dial lamp is what lights up the display of the factory radio. The grey wire should only have juice on it when your lights are on. They might have tied other items to the radio fuse.

[Toppless72]

Scott,

 

As Robert has explained, the dial lamp is powered by the gray 20g. wire in the original radio. It just lights the dial so it can be seen at night. It’s controlled by the headlight switch and only receives 12 volts positive when the headlight switch is moved to the parking light mode. It remains energized when the headlight switch is moved the full headlamp mode. The issue you have is that a switched 12 volt power source is connected into your parking light circuit after your headlamp switch.

 

Behind the instrument panel all the factory lighting for the instrumentation is via the cluster printed board or, by 20g. gray wires running to the heater control unit and in the harness to the radio. Also, if your car has a console, there will be a gray wire in the harness running to it to illuminate the shift indicator when the headlamps/parking lamps are on.

 

Unless something else has been added, by your discovery of the radio fuse causing the lights to go off, it’s clear the yellow power wire in the original radio harness is making contact with the lighting circuit wiring. The yellow wire comes directly from the fuse panel to the radio. Nothing else should be connected to this yellow wire. The gray wire also comes from the fuse box and just behind the instrument panel it will split into three wires. One goes to the radio, one to the heater control unit and one to the harness that plugs into the back of the cluster.

 

Your mission is to insure these wires are not contacting anything. I still believe your power wire for the radio is contacting the gray wire for the lighting circuit somewhere.

 

Please let us know what you find out.

[Its Just Me]

Score one for the good guys!

Joe, you were dead on...I dug around in the mess of wires that was the connection to the aftermarket radio. What I found was, whoever installed the "new" radio, cut the original radio connector off, then proceeded to twist the gray and yellow wire together, and nicely wrapped it in e-tape. I un-wrapped and un-twisted the wire and waa-laa...no more lights with the key switch.

After doing the happy dance, I clipped the yellow & gray wires back to the insulation, folded the gray wire back then wrapped them all together with e-tape.

Thanks to all who have helped me with this (and other) issues. It may sound old and rehashed, but this is, by far, the best and most generous Club anyone could ever be a part of...I just wish I would have joined sooner.

Thanks again!

Scott

[Toppless72]

Scott,

 

I'm glad you found it. Searching out those electrical gremlins is my favorite part of tinkering with these old buggies.

 

Joe

[stangeba]

Thanks for letting us know what it was.