Yep
71 Ground Problem
Thread Starter
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
71 Ground Problem
I'll try to make this as short as possible.
My '71 interior lights haven't worked since I bought it. Got new door switches and replaced them. Put a new 20a fuse in and lights work. TADA!
Then...
I'm checking the wire routing before I put the kick panels back on, and feel that the wires from the switches are getting very warm. Immediately pop the fuse back out.
Remove switches and notice that the plastic part that the wire connectors plug into for the plunger to make contact with are partially melted.
I'm thinking there has to be a bad ground, but can't quite figure out where to look after being inundated with all the stuff on the wiring diagrams in the Factory Service Manual.
Anyone else ever run into this? Until I figure this out, I have no Lighter/Clock/Interior Lamps.
Thanx in advance.
My '71 interior lights haven't worked since I bought it. Got new door switches and replaced them. Put a new 20a fuse in and lights work. TADA!
Then...
I'm checking the wire routing before I put the kick panels back on, and feel that the wires from the switches are getting very warm. Immediately pop the fuse back out.
Remove switches and notice that the plastic part that the wire connectors plug into for the plunger to make contact with are partially melted.
I'm thinking there has to be a bad ground, but can't quite figure out where to look after being inundated with all the stuff on the wiring diagrams in the Factory Service Manual.
Anyone else ever run into this? Until I figure this out, I have no Lighter/Clock/Interior Lamps.
Thanx in advance.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Its not a bad ground, the switches furnish a ground to turn on the lights. The problem os somewhere else, there is a short somewhere, maybe the light timer, the excess current is running to ground thru the switches, thats why they are heating up.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
You do only have one wire running to each switch, right? The switches ground through the frame so you shouldn't have a ground wire on them.
Bubba wasn't smart enough to scrape off a little excess paint in the door jamb on my car and ran a separate ground for the switch instead. It didn't work.
cc
Bubba wasn't smart enough to scrape off a little excess paint in the door jamb on my car and ran a separate ground for the switch instead. It didn't work.
cc
Thread Starter
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
You do only have one wire running to each switch, right? The switches ground through the frame so you shouldn't have a ground wire on them.
Bubba wasn't smart enough to scrape off a little excess paint in the door jamb on my car and ran a separate ground for the switch instead. It didn't work.
cc
Bubba wasn't smart enough to scrape off a little excess paint in the door jamb on my car and ran a separate ground for the switch instead. It didn't work.
cc
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
If that second wire touches the plunger when the door is open then you have found your problem. That would create a dead short. The threaded nut on the switch makes the ground connection to the chassis. You should only have a hot wire coming in contact with the plunger with the door open.
cc
cc
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Melting Slicks
Joined: Aug 1999
Posts: 3,123
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From: Hollywood, Florida
Thread Starter
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
Courtesy lamp switches on front jamb. Haven't messed with the door ajar switch yet since this problem presented itself.
There are 2 wires that go into the plastic piece on the switch on the driver side, and when the plunger touches them both (door open), it completes the circuit and the lights come on.
I understand that the ground should be the switch screwed into the pillar, but there are 2 wires.
???
There are 2 wires that go into the plastic piece on the switch on the driver side, and when the plunger touches them both (door open), it completes the circuit and the lights come on.
I understand that the ground should be the switch screwed into the pillar, but there are 2 wires.
???
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Courtesy lamp switches on front jamb. Haven't messed with the door ajar switch yet since this problem presented itself.
There are 2 wires that go into the plastic piece on the switch on the driver side, and when the plunger touches them both (door open), it completes the circuit and the lights come on.
I understand that the ground should be the switch screwed into the pillar, but there are 2 wires.
???
There are 2 wires that go into the plastic piece on the switch on the driver side, and when the plunger touches them both (door open), it completes the circuit and the lights come on.
I understand that the ground should be the switch screwed into the pillar, but there are 2 wires.
???
I would dig out a digital volt meter and see what kind of amperage your courtesy lights are drawing. For the wires to get noticeably hot there has to be a short to ground in that curcuit somewhere.
cc
Thread Starter
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
I'm with you. Just have to really go over the diagrams again next time I have more than 2 minutes to myself. Thanx.