'70 Vette Guages/Elec Problem?

[Papa]

I'm a newbie here...been shopping for a C3. Found one at a pretty good deal but none of guages, radio or wipers work (Except Speedo and Oil Pressure) according to seller (Dealer). Dealer is wholesaler that sells a few retail to maintain license. Curious about this being a possible quick fix or nightmare? Any thoughts or specific areas to investigate (I figure fuses is always a good place to start ...supposedly car sat for a while) but nay other thoughts or ideas are very welcome.
Thanks

 

[jdp6000]

None of those things are hard to fix. If the car runs fine and is priced right it may be worth going for.

It could be a fuse. Wiper switch is cheap. The center cluster guages are not working because of the harness or circuit board most likely.

Be more concerned with the mechanical and frame (rust).

Jim

 

[Papa]

Thanks Jim. Once I pass the fuses and obvious checks with voltmeter I get a bit lost, but suspect there is more than enough reference material available to sort it out. I am going to try to see the car up close and personal this weekend. Intended a good once over of undercarriage, under hood and the obvious stuff. Dealer claims carb needs work (running rich) but believes it is original QJ and I want to try to verify its truly a matching numbers (350/300HP). Im looking for a driver not a trailer queen, that can be tinkered with and enjoyed (Is that an oxymoron?)

 

[Vettehead Mikey]

Some of the gauges you mention are mechanical, and none of them AFAIK go through a fuse or at least a common fuse.

You might be looking at several unrelated problems

 

[Jack]

Seem to recall there've been some pretty bad floods in TX past few years. First thing I'd suggest is for you to investigate if this car may've been victim of Texas flooding or similar waterborne illness.
JACK:gap

 

[Papa]

Which ones are which?

Some are mechanical?? I know the tach should be mechanical and the issue could be that someone switched distributors or tach drive could be faulty? What else is mechanical? ..Oil pressure is driven by a sending unit I believe but it works ...fuel guage is electrical(Sending unit in tank?)? Voltage is Electrical (from Alternator/voltage regulator)? Temp is electrical(Sending unit in block?) ? I admit to working on some really old recollections/assumptions as I haven't been constructively under a hood in about 30 years other than oil/filter/aIr & fuel filter and battery changes.

 

[Papa]

Flooding...

There have indeed but those were in the Texas Hill Country. This car supposedly came from East Central Texas area which hasnt seen those kinds of problems...also pics show a car that appears to have been pretty well cared for and the guy selling it (bought for resale) doesnt seem to have spent much time on anything but replacing brake calipers/tires and very minimal cosmetic cleanup...closer personal inspection should tell more but it is another thing to look for?

 

[Bob Chadwick]

I think the oil guage for this year is mechanical as well.

Get your hands on a diagram of the electrical circuit and see, what if anything, these items have in common. All of the gauges on my 77 work off one fuse. Also on that fuse was the relay for the power windows. I blew the fuse and the gauges quit working, the alt light came on and the windows quit working. No idea of what the problem was. Took a look at the circuit diagram and almost immediately knew what the problem was.

 

[jdp6000]

I don't know if yours is the same. but my guage didn't work either when I got the car. I had a break in the circuit board where the plug goes into it. I repaired the break and they started to work. Are you getting lights on the center guage cluster?

With the one you are looking at...could be the board, could be wiring, could be fuses, could be the sending units, could be the guages.

check all the fuses. wipers have one, radio needs two, cluster needs one.

Is there a tach drive cable at the base of your distributor??? I don't think the 70 was electrical.

have you checked the car out yet???

Jim

 

[jdp6000]

Forgot to mention. The mere fact that your volt guage doesn't work suggests minor electical problem.

Jim

 

[Papa]

Good stuff..

Thanks Bob and Jim
I havent been able to arrange to see it yet...probably Saturday...
Have only seen pictures and asked seller (wholesale dealer) a load of questions...he said only Speedo and Oil Pressure were working...didnt ask about dash lights. He also said radio and wipers didnt work.

If I buy it an elec diagram will be one of first things...along with shop manual.
Since its a "bumper car" and the price is excellent based on my searching it's a strong candidate for a purchase...but needs an inspection of body, mechanicals, undercarriage etc to decide. Texas does require state inspections for general safety and "pollution" and he said it did have a current inspection tag which doesnt speak volumes but is mildly encouraging (or misleading :eyerole )

Dumb Question....what circuit board and where is it? (Fusebox area or ?)

 

[jdp6000]

fuse box should be just above and to the left of the brake pedal. the guages (volts, gas, temp, etc) are on a panel in the center of the dash above the radio. The guages attach to a printed plastic circuit board. The harness plugs into the circuit board. Just below this harness is another that feeds the radio among other things. The tach should have a cable that runs from it to the distributor (once again i don't think the tach in a 70 is electrical but rather mechanical.)

How much are they asking for this car???

Jim

 

[Bob Chadwick]

There is a circuit board behind the instruments. If it is the same as the 77, a plug plugs into the circuit board and distributes the electrical signal accordingly.

 

[Vettehead Mikey]

Guys,

I'm assuming this is an early 70's car based on the the 350/300HP and bumper car statements, so the gauge drivers and set up is quite different from late 70's and 80's cars.

The Speedo and Tach are mechanical
Fuel is electrical
Oil pressure is mechanical
Water temp is electrical
Battery Charge (not voltage) is electrical
Clock is electromechanical

If the gauge lights also don't work, it may be a simple grounding problem.

 

[Papa]

What I know ?

Guys,

I'm assuming this is an early 70's car based on the the 350/300HP and bumper car statements, so the gauge drivers and set up is quite different from late 70's and 80's cars.

Car is a 70 coupe w/auto trans supposed to be matching number which woudl make it 350/300HP

The Speedo and Tach are mechanical Speedo works tach doesnt...suspect tach drive or swapped distrib)
Fuel is electrical - Doesnt work
Oil pressure is mechanical - Works
Water temp is electrical - Doesnt Work
Battery Charge (not voltage) is electrical - Doesnt work
Clock is electromechanical - Doesnt work

If the gauge lights also don't work, it may be a simple grounding problem - Not sure

 

[Papa]

Final after look see

The 70 was a great canddiate for a totla restore but didnt live up to the pictures by a long shot...good new is the guys buddy has a very nice 72 although not matching numbers but very nice...so could be the one ? Stay tuned