Electrical / Headlamp Switch
Thread Starter
Intermediate
Joined: May 2012
Posts: 30
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From: Knoxville TN
Electrical / Headlamp Switch
Sorry guys. I'm sure some permutation has been asked before...
(1) There is a metal strap running from the face of the face of the headlamp switch to the speedometer housing. Is this a ground strap?
I've installed new wiring harnesses in my 74 and of course I'm having problems. Here are a couple of symptoms:
a) When the running lights are off, the front and front side turn signals blink simultaneously, when on they alternate blinking.
b) The courtesy lights turn on when the door opens but not when the dimmer switch is turned up full and the door is closed.
c) A short occurs with the door open and the dimmer full up. It blows the tail light fuse. Door closed, no short.
Oh and about that strap in (1) above, I can't believe it's not a ground because I can't believe GM would allow a naked metal housing that isn't grounded. When I ground it, the courtesy lights turn on when the dimmer is full up and the door closed.
I really don't want to pull the out the dash _again_.
Thanks
Mark
(1) There is a metal strap running from the face of the face of the headlamp switch to the speedometer housing. Is this a ground strap?
I've installed new wiring harnesses in my 74 and of course I'm having problems. Here are a couple of symptoms:
a) When the running lights are off, the front and front side turn signals blink simultaneously, when on they alternate blinking.
b) The courtesy lights turn on when the door opens but not when the dimmer switch is turned up full and the door is closed.
c) A short occurs with the door open and the dimmer full up. It blows the tail light fuse. Door closed, no short.
Oh and about that strap in (1) above, I can't believe it's not a ground because I can't believe GM would allow a naked metal housing that isn't grounded. When I ground it, the courtesy lights turn on when the dimmer is full up and the door closed.
I really don't want to pull the out the dash _again_.
Thanks
Mark
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
The strap is a ground for the headlamp switch to the dash. There should also be a strap between the tach and speedo.
Are you sure you have the ground hooked up to the back of the gauges? There is one on the back of the tach and one on the back of the speedometer.
Are you sure you have the ground hooked up to the back of the gauges? There is one on the back of the tach and one on the back of the speedometer.
Thread Starter
Intermediate
Joined: May 2012
Posts: 30
Likes: 0
From: Knoxville TN
I recall hooking up the hooded grounds to the spade connectors on the speedo, tach, and gauge tin pots. I tested each ground.
I couldn't get ground at the strap. I assumed paint isolated it. So I hooked a ground to it with an alligator clip. It worked fine until I opened the door to turn on the courtesy lights first then turned the dimmer full on. A bunch of amps jumped right across my alligator ground and melted its insulation.
I couldn't get ground at the strap. I assumed paint isolated it. So I hooked a ground to it with an alligator clip. It worked fine until I opened the door to turn on the courtesy lights first then turned the dimmer full on. A bunch of amps jumped right across my alligator ground and melted its insulation.
The strap is a ground for the headlamp switch to the dash. There should also be a strap between the tach and speedo.
Are you sure you have the ground hooked up to the back of the gauges? There is one on the back of the tach and one on the back of the speedometer.
Are you sure you have the ground hooked up to the back of the gauges? There is one on the back of the tach and one on the back of the speedometer.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
