Dash lights still out

[Bill 77]

Well its me again more problems.Put dash back together.Put used head light swicth in still no dash lights.Does any one have any ideas.I dont have owners manual to find which fuse it is .They all look good.Ihave neck and back pains from being down there so long.Any advice would add another year to my life.Thanks Bill

 

[Alan76]

Used electical parts are not the way to go as hard as it is to deal with the left side of the dash. The best way to go is new parts, I replaced my speedometer and while I was there, I replaced the headlamp switch so the odds of having to go back in will be reduced. While I am there I will also change all the bulbs. Nothing is 100% but while your there you might as well use new parts
Alan

 

[lucky76]

no dash lights

Well its me again more problems.Put dash back together.Put used head light swicth in still no dash lights.Does any one have any ideas.I dont have owners manual to find which fuse it is .They all look good.Ihave neck and back pains from being down there so long.Any advice would add another year to my life.Thanks Bill

I have the HAYES CHEVROLET CORVETTE 1968 THRU 1982 AUTOMOTIVE REPAIR MANUAL #274 from O'Reillys Auto I think (previous owner bought it). It shows a 4 amp fuse marked "INST LPS" on the fuse block for the instrument lights. Also I see that pin 1 on the head light switch is battery and pin 2 is PNL LP FUSED (panel lamp) which should be the fuse above. This is the output to the lamps when you twist the light switch rheostat to make the dash lights brighter. Pin 3 is not used, pin 4 TL LP, pin 5 is TL LP FUSED and pin 6 is HD LP.
There is also a ground INSTR CLSTR GND for the lights somewhere on the body which could be broken or loose. All grounds for these lights are bunched together and grounded somewhere. Maybe someone else knows where it is connected. Hope this helps some.

 

[Bill 77]

Thanks again guys.My headlight switch was cracked porcelin part thought my have been the reason.Bought used headlight switch said it was tested and worked.Lucky thanks that might help me alot.Fuses look good ,though bought car a year ago
been working on ever since ,still have radiator support, and rear caliper leaking,Need front bumper,spring is here snow is melted . But every time I try to work on car . Wife has other jobs need to be done.Has anyone else felt this pain.Well thanks again you guys are great.Bill 77

 

[80convertible]

I feel your pain. I've owned my vette for 6 years, and it's been a lot of time, money and sweat. I'm rebuilding the entire rear suspension right now including trailing arms. I'm already over budget and have not even finished buying replacement parts yet.

Electrical diagnosis is sometimes the most frustrating task. I often find that walking away from the car for a few days and coming back with a fresh perspective helps. Two things you have to have are a detailed wiring schematic and a multimeter. You may already have them. I always begin by double and triple checking my wiring. If an entire circuit is dead and it's not the fuse, typically it's the ground wire. When my tach quite working, it was due to corrossion on the connections. I've even found a ground wire that was connected with an old rusty screw that was preventing a solid connection.
Make sure all the connectors in the circuit are clean. You can use a pencil eraser to clean the connectors or 200+ grit sandpaper (very lightly). Also I only buy used parts when they are expensive. A replacement light switch is cheap, so you may want to invest in a new one.

 

[Bob Chadwick]

See if these pages from the 77 Electrical Troubleshooting Manual help. This manual is on EBay all the time ofr under $10. If you are having electrical problems you might want to consider purchasing one.

Download the pictures and you can use an graphics viewer editor to take a look at them. They were scanned at fairly high resolution so you should have what you need to get them to a decent size.

Page 1
Page 2
Page 3

I'm not the best at reading wiring schematics but it appears that power comes to the switch from an orange wire from the taillights and out of the switch with a green wire through the 5 amp fuse in the fusebox, where the wire becomes gray and goes to the lights.

With the switch on, I would check the orange and green wire for power using a test light at the switch. If power at the orange and not at the green then you have a bad switch.

I would then check the green wire at the fuse box to see if power was making it that far. I would then check for power coming out of the fuse box at the gray wire.

If power to these points, I would then check the ground at the pillar. If all of these are good, at least you know your problem is between two points and you can start tracing wires and checking them.

 

[Bill 77]

Dash lights fixed . Wasbad ground wire located on drivers side pillar. Thanks everyone.Bill