When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello I have a 76 corvette and I’m having issues with the dash lights. They stopped working a while back and I just now have had time to look at everything to see what could be the issue. I checked the fuses and none of them seem to have been blown besides the tiny 4A fuse marked LPS which I just replaced and that only seemed to have fixed the light next the the shifter. I read that it could be the headlight switch to which I rotated each way to see if maybe anything would come back to life but the only difference was that the light near the shifter would turn off or on depending on the way I moved it. (The only lights that work are the parking brake light, high beam light and the lights that turn on when the door is opened) does anyone have any idea on what it could be? Thanks in advance
Last edited by Joshua Ruiz; Dec 17, 2021 at 08:58 PM.
Hello I have a 76 corvette and I’m having issues with the dash lights. They stopped working a while back and I just now have had time to look at everything to see what could be the issue. I checked the fuses and none of them seem to have been blown besides the tiny 4A fuse marked LPS which I just replaced and that only seemed to have fixed the light next the the shifter. I read that it could be the headlight switch to which I rotated each way to see if maybe anything would come back to life but the only difference was that the light near the shifter would turn off or on depending on the way I moved it. (The only lights that work are the parking brake light, high beam light and the lights that turn on when the door is opened) does anyone have any idea on what it could be? Thanks in advance
To start, verify that the dash is grounded.
Easy to test; simply grab a length of wire, attach one end to the negative side of the battery and touch the other end to a bare metal part of the dash/center cluster and see if the lights come on.
If that works at least you know you're looking for a bad ground.
The Grounds to both the Speedometer & Tachometer are a common chassis ground.
There is a ground lug on both the Speedo & Tach.
Each of these ground lugs ground their respective cases.
So "if" you have a Hi-Beam light I would suspect at least your Speedo case is grounded properly and the back lighting should work GRAY sockets.
Do the R & L Turn signal light indicator bulbs light up? If so, this also tells you that the case grounds are good.
The LPS fuse powers ALL your gauge lighting including your Speedo/Tach & Center Instrument Cluster lighting.
Your LPS fuse powers all the bulbs in the sockets labeled GRAY on the Speedo/Tach & Center Cluster including your shift selector light.
Check your LPS fuse again then try repeating rotating the headlight switch **** several more time, I believe your problem is in the LPS circuit not a ground issue.
Your Courtesy lighting (Doors & Under Dash) is on a completely different circuit.
Last edited by bmotojoe; Dec 18, 2021 at 10:37 AM.
Reason: Do the R & L Turn signal light indicator bulbs light up?
Here is a drawing showing the LPS circuit.
This drawing is for a 77, your 76 center gauges cluster will have several GRAY wires going to it where the 77 uses a printed circuit board and only requires 1 GRAY wire.
You also don't I believe have a HVAC overhead light so I X it out of the circuit.
The Grounds to both the Speedometer & Tachometer are a common chassis ground.
There is a ground lug on both the Speedo & Tach.
Each of these ground lugs ground their respective cases.
So "if" you have a Hi-Beam light I would suspect at least your Speedo case is grounded properly and the back lighting should work GRAY sockets.
Do the R & L Turn signal light indicator bulbs light up? If so, this also tells you that the case grounds are good.
The LPS fuse powers ALL your gauge lighting including your Speedo/Tach & Center Instrument Cluster lighting.
Your LPS fuse powers all the bulbs in the sockets labeled GRAY on the Speedo/Tach & Center Cluster including your shift selector light.
Check your LPS fuse again then try repeating rotating the headlight switch **** several more time, I believe your problem is in the LPS circuit not a ground issue.
Your Courtesy lighting (Doors & Under Dash) is on a completely different circuit.
Thanks you for the response. the turn signals work, I’ll double check the Lps fuse again to make sure I get power from both sides and see if anything is visually wrong with it as it is a new fuze. I pulled the the cluster out and checked the some of the bulbs and noticed that a few of them did not have the metal crowns on the socket like how the rest of them had. Are those the things that ground the socket or bulb? If I need to get new ones would you know where I could get those little crown looking things or do you happen to know the name of them? Thank you.
To start, verify that the dash is grounded.
Easy to test; simply grab a length of wire, attach one end to the negative side of the battery and touch the other end to a bare metal part of the dash/center cluster and see if the lights come on.
If that works at least you know you're looking for a bad ground.
Alright, I’ll try that out when I get that chance thank you.
Here is a drawing showing the LPS circuit.
This drawing is for a 77, your 76 center gauges cluster will have several GRAY wires going to it where the 77 uses a printed circuit board and only requires 1 GRAY wire.
You also don't I believe have a HVAC overhead light so I X it out of the circuit.
thank you I’ll have my brother look at this since he’s more knowledgeable in wiring and electrical and see if he can help as well.
Thanks you for the response. the turn signals work, I’ll double check the Lps fuse again to make sure I get power from both sides and see if anything is visually wrong with it as it is a new fuze. I pulled the the cluster out and checked the some of the bulbs 1. and noticed that a few of them did not have the metal crowns on the socket like how the rest of them had. 2. Are those the things that ground the socket or bulb? If I need to get new ones would you know where I could get those little crown looking things or 3. do you happen to know the name of them? Thank you.
1. On the Speedo/Tach cluster the only one I know of that doesn't require the ground ring is the Brake Light Bulb. All others including turn signal should have them.
2. Yes
3. Zip Corvette sells the Gray wire with bulb socket as a assembly. https://www.corvettecentral.com/c3-6...ht-bulb-661073
If you don't care about the wire colors being correct Napa sell this one that you might try, I think it is for a 5/8" hole and should work. https://www.napaonline.com/en/p/ECHLS6225
1. On the Speedo/Tach cluster the only one I know of that doesn't require the ground ring is the Brake Light Bulb. All others including turn signal should have them.
2. Yes
3. Zip Corvette sells the Gray wire with bulb socket as a assembly. https://www.corvettecentral.com/c3-6...ht-bulb-661073
If you don't care about the wire colors being correct Napa sell this one that you might try, I think it is for a 5/8" hole and should work. https://www.napaonline.com/en/p/ECHLS6225
Alright I’ll replaced the ones with the missing rings which will probably make them work now. I also got to checking the fuse and it was only getting power one one side I checked it and realized I put in the old blown one in by mistake 😅. I’ll get to replacing it soon. Thank you for your help!
Dash light problem
