Troubleshooting instrument lights
Thread Starter
Team Owner
Joined: May 2005
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Troubleshooting instrument lights
I would appreciate some advice on this.
The instrument lights on my 1970 all went out at once. I'm talking about the lights that illuminate the gauges. The warning lights all still work, like the parking brake light, the seat belt light, and the green directional indicators.
The 5A instrument light fuse is OK, so I'm thinking that the problem might be the instrument light dimmer in the headlight switch. What's the best way to check this out before replacing anything?
Thanks for the help!
The instrument lights on my 1970 all went out at once. I'm talking about the lights that illuminate the gauges. The warning lights all still work, like the parking brake light, the seat belt light, and the green directional indicators.
The 5A instrument light fuse is OK, so I'm thinking that the problem might be the instrument light dimmer in the headlight switch. What's the best way to check this out before replacing anything?
Thanks for the help!
Team Owner
Joined: Sep 2006
Posts: 31,274
Likes: 4,366
From: Westminster Maryland
Hi RiM,
I believe the dimmer reo-stat on the headlight switch also dims the interior courtesy lamps... are they still working.
Is the top part of your center gauge bezel cracked loose from the bottom? That can lead to no gauge lights because the ground for the bulbs is through the bezel.
Maybe?
Regards,
Alan
I believe the dimmer reo-stat on the headlight switch also dims the interior courtesy lamps... are they still working.
Is the top part of your center gauge bezel cracked loose from the bottom? That can lead to no gauge lights because the ground for the bulbs is through the bezel.
Maybe?
Regards,
Alan
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
I would appreciate some advice on this.
The instrument lights on my 1970 all went out at once. I'm talking about the lights that illuminate the gauges. The warning lights all still work, like the parking brake light, the seat belt light, and the green directional indicators.
The 5A instrument light fuse is OK, so I'm thinking that the problem might be the instrument light dimmer in the headlight switch. What's the best way to check this out before replacing anything?
Thanks for the help!
The instrument lights on my 1970 all went out at once. I'm talking about the lights that illuminate the gauges. The warning lights all still work, like the parking brake light, the seat belt light, and the green directional indicators.
The 5A instrument light fuse is OK, so I'm thinking that the problem might be the instrument light dimmer in the headlight switch. What's the best way to check this out before replacing anything?
Thanks for the help!
So if you don't have power at the fuse, just to to the switch and see if it is powering up.
The interior courtesy lamps are on the orange wire circuit and hot at all times.
Willcox
Last edited by Willcox Corvette; Jul 13, 2013 at 06:07 PM.
Thread Starter
Team Owner
Joined: May 2005
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Do you have power at the fuse? The power goes into the fuse panel from the headlamps switch on the dark green wire. It leaves the fuse panel as Gray... All dash lamps are on this same gray wire circuit.
So if you don't have power at the fuse, just to to the switch and see if it is powering up.
The interior courtesy lamps are on the orange wire circuit and hot at all times.
Willcox
So if you don't have power at the fuse, just to to the switch and see if it is powering up.
The interior courtesy lamps are on the orange wire circuit and hot at all times.
Willcox
Thread Starter
Team Owner
Joined: May 2005
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Wilcox...Sorry but I have a stupid question:
Can I just pull the fuse and then put a test light across the fuse terminals to see if there is power? Or should I leave the fuse in and go from one end of the fuse to ground through the test light? If the latter, is there a ground terminal on the fuse box?
This may be basic to some, but not to me.
Can I just pull the fuse and then put a test light across the fuse terminals to see if there is power? Or should I leave the fuse in and go from one end of the fuse to ground through the test light? If the latter, is there a ground terminal on the fuse box?
This may be basic to some, but not to me.
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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With the fuse removed you will only have power on one side (fuse holder clip).
Install a new fuse and check for 12 volts on both clips.
Tail light fuse feeds the headlight rheostat.
Jumper from "Courtest light fuse" to "instrument light fuse".
If dash bulbs light up the rheostat in the headlight switch is bad.
Install a new fuse and check for 12 volts on both clips.
Tail light fuse feeds the headlight rheostat.
Jumper from "Courtest light fuse" to "instrument light fuse".
If dash bulbs light up the rheostat in the headlight switch is bad.
Thread Starter
Team Owner
Joined: May 2005
Posts: 37,583
Likes: 5
With the fuse removed you will only have power on one side (fuse holder clip).
Install a new fuse and check for 12 volts on both clips.
Tail light fuse feeds the headlight rheostat.
Jumper from "Courtest light fuse" to "instrument light fuse".
If dash bulbs light up the rheostat in the headlight switch is bad.
Install a new fuse and check for 12 volts on both clips.
Tail light fuse feeds the headlight rheostat.
Jumper from "Courtest light fuse" to "instrument light fuse".
If dash bulbs light up the rheostat in the headlight switch is bad.
Thanks!
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Pete is on it too... and what a great idea... With the fuse out you can jumper power to the right terminal from another fuse to see if the problem is past the fuse. Of coarse if you have power to the left terminal then the problem is from the right one forward.
Willcox
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Thread Starter
Team Owner
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Use the door jamb switch.. or run one from the engine to the inside of the car.
Pete is on it too... and what a great idea... With the fuse out you can jumper power to the right terminal from another fuse to see if the problem is past the fuse. Of coarse if you have power to the left terminal then the problem is from the right one forward.
Willcox
Pete is on it too... and what a great idea... With the fuse out you can jumper power to the right terminal from another fuse to see if the problem is past the fuse. Of coarse if you have power to the left terminal then the problem is from the right one forward.
Willcox
I really appreciate the quick responses and the insights!
Will be going after this when I get back to my car later in the week.