snesic

I am new to this forum, just joined. Last week I got a 78 Corvette in decent shape. However, none of the gauges on the central console seem to work (fuel, temp., oil, etc.). Since none of them are working I am inclined to think they are not getting power, so I tried to look if something was disconnected or if a fuse was blown, without any success. Can anyone suggest how to go about fixing this problem?

TimAT

If the gauges fuse in the panel is good, (I'd check with a test light) I'd start to suspect the ground.
Willcox has a great set of instructions on testing and troubleshooting those small gauges. The following link will get you to Willcox' site, it's on you to find what you need and follow the directions.

http://repairs.willcoxcorvette.com/c...erature-gauge/

ronarndt

Welcome to the forum and also to the electrical problems with older cars. I'll let someone with a 1978 Vette give the advice, but on my 1968 convert, the center console gauges all rely on getting a ground from somewhere, since the car is fiberglass and the center console has to be grounded by a wire or strap connected to metal and to the engine or car frame.

Easy Mike

Sounds like the harness plug may be loose.

snesic

I checked the "GAUGES" fuse in the panel and it works (assuming it isthe same fuse as used for the other two main gauges - speedometer and tachometer), and will check the ground connections when I get a chance

snesic

I will check the harness plug, I assume it is tucked somewhere behind the central console, did not spot it when I looked the first time

Easy Mike

Directly behind the center gauge cluster. Everything plugs into the integrated circuit board on the back of the cluster.

SwampeastMike

All of the gauges in your '78 share a single ground. If the connector is secure there's a good chance that the printed circuit that powers everything is shot. Those printed circuits are two layers of plastic with copper traces between. They tend to delaminate over time causing the traces to break or short out. All of the vendors sell replacements. The one I got (from Willcox) is of excellent quality but is significantly thinner than the original. This caused the low fuel module to work loose. Solution: cut a piece of pasteboard (like from the back of a notepad) to fit between the housing and the circuit.

snesic

Thanks, I will see if I am game to take this apart myself or will have to take it to a PRO.

snesic

Thanks. How hard is it to get to the ground wire and to the printed circuit. Is this doable by an amateur like me or does it take a professional?

SwampeastMike

The ground for the gauges (and its lighting) leads to a splice in main cabin wiring harness which in turn leads to the single grounding bolt installed in the driver side "A" pillar. If other things in the cabin work then a grounding problem is way down the list of suspected problems.

The gauge pack (what Chevrolet calls the bezel that holds the gauges) isn't particularly difficult to remove but in my opinion it is best (particularly if you have a factory radio) to also take off the parking brake cover and slightly relocate the shifter bezel. Once the gauge pack is removed the printed circuit is easy to both examine for problems and remove/replace.

Do you have basic tools? All you really need are #2 Phillips (including a "stubby") and nut drivers or a socket set.

You may have to remove the seats of a '78 if it's not a Pace Car (with the "clamshell" seats) to remove the carpeted trim on both sides of the center console. I have a '79 with those seats and while it's more convenient to remove the seats (you MUST have about a foot of extension for the socket to access the rear bolts) it's not utterly necessary.