Fuse Pannel Problem - HELP!
Thread Starter
Heel & Toe
Joined: Feb 2006
Posts: 15
Likes: 0
Fuse Pannel Problem - HELP!
I have a 71 Coupe that my wife and I have been doing some work on since April. We recently had the dash out and have it all back in now but the instrument lights won't work. I looked at the fuse pannel and it takes a 5 amp fuse that is about 1/2 inch long. Well someone put a 9 amp fuse in that is 3/4 inch long. One side was clipped inside the holder and the other was pushed up against the pannel and still making a connection with the connection clip.
I pulled that fuse and replaced it with the correct fuse but it still doesn't work. With the fuse OUT and using a test probe light when I make contact with the clip on one side it shows current when lights are on (like it should) while the other side shows no current. When I put the fuse in both sides show no current ???
I thought maybe when the fuse was in the clip was seperating and dropping the connection. I put the fuse in the HOT side of the clip making sure it didn't touch the cold side and checked for current at the end of the fuse. It was showing current. I put the fuse into both clips and lost connection ???
Help anyone.
I pulled that fuse and replaced it with the correct fuse but it still doesn't work. With the fuse OUT and using a test probe light when I make contact with the clip on one side it shows current when lights are on (like it should) while the other side shows no current. When I put the fuse in both sides show no current ???
I thought maybe when the fuse was in the clip was seperating and dropping the connection. I put the fuse in the HOT side of the clip making sure it didn't touch the cold side and checked for current at the end of the fuse. It was showing current. I put the fuse into both clips and lost connection ???
Help anyone.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Which instrument lights do not work? All them, including the tell-tales, or only the illumination lamps?
If all of them are out (no tell-tales and no panel lamps), check the IP wiring harness ground on the driver's door hinge post.
If you have some lights, but no illumination lamps, check the rheostat in the headlight switch.
If all of them are out (no tell-tales and no panel lamps), check the IP wiring harness ground on the driver's door hinge post.
If you have some lights, but no illumination lamps, check the rheostat in the headlight switch.
Instructor
Joined: Nov 2003
Posts: 106
Likes: 1
From: Indiana
Have you established that you have a good ground on the back of the speedo and tach housing? The tach and speedo both serve as a ground for the gray wires when plugged in to them. If you left the black wire off the cluster the lights won’t work.
Pull one of the sockets out and test to see if you have current on them using a known ground for your source. If you have current, then you have a ground issue. If you don’t have current then you have another problem.
I saw a post the other day where someone suggested checking the headlamp switch! If you have it dimmed to the lowest point, you won’t see the bulbs light.
If you don’t have current on the bulb socket then you need to go to the power feed wire from the headlamp switch to see if it has power. The dash bulbs are fed current from the resistance coil wire on the headlamp switch. I believe the gray wires all feed back on a single gray wire to the fuse panel. Once they pass through the fuse panel the wire turns to Dark Green all the way to the headlamp switch. You might double check this on a wire diagram before you dig in to it.
Pull one of the sockets out and test to see if you have current on them using a known ground for your source. If you have current, then you have a ground issue. If you don’t have current then you have another problem.
I saw a post the other day where someone suggested checking the headlamp switch! If you have it dimmed to the lowest point, you won’t see the bulbs light.
If you don’t have current on the bulb socket then you need to go to the power feed wire from the headlamp switch to see if it has power. The dash bulbs are fed current from the resistance coil wire on the headlamp switch. I believe the gray wires all feed back on a single gray wire to the fuse panel. Once they pass through the fuse panel the wire turns to Dark Green all the way to the headlamp switch. You might double check this on a wire diagram before you dig in to it.
Pro
Joined: Jul 2002
Posts: 514
Likes: 44
From: Toronto Ont
I just solved my problem and thought this might help you out.
Trace all the grey wires they are the key, at least on my 79.
http://forums.corvetteforum.com/show....php?t=1468778
good luck!
Trace all the grey wires they are the key, at least on my 79.
http://forums.corvetteforum.com/show....php?t=1468778
good luck!
Instructor
Joined: Sep 2002
Posts: 198
Likes: 0
From: VA BEACH VA
I had the same problem after working on my dash. All of the fuses looked OK, wiring seemed to be OK and it turned out that I had shorted something out while working on it and blew all of the bulbs. I replaced the old ones with new ones and haven't had a problem since.
