Hello all. I just picked a fairly nice 74 rag top last week and have already found some electrical issues.

For starters, what is the 3-way switch on the center console near the gas pedal? It looks stock, but it docent seem to do anything..

Now for my issues. When I picked it up, the last owner said that everything works but he did pop a couple of fuses over the past few years... On the ride home, I used my parking lights, to which my wife said were working correctly. So I went to put it in the garage and noticed that with the headlight switch pulled out, only the headlights and tail lights worked, but no parking lights. So I went into the garage and looked under the dash and noticed a lot of the wires appear to have been added to, as there is a bunch of blue wire splices. So I tried it again, and now, all I have are headlights, no parking lights or tail lights.... Blinkers and break lights do work.

Oh, and I dont have any dash lights...

I have never worked on a Vette, so any suggestion would help.

Do they make a new wiring harness for our cars..??

Thanks
Steve

 

On a coupe, the rocker switch is for the rear window defroster. Small blower unit in the rear that 'supposedly' helped clear the rear glass.

 

Sure is! That also answers the question to the noise coming from behind my head....

 

Welcome to the forum. You'll find lots of high quality advice here. I have a '73 that sounds a lot like yours. I have since installed all new wiring from bumper to bumper and now everything works Lucky for you, the front headlight wiring harness is available from several of the forum sponsors and is also one of the easiest to install. I strongly suggest that you buy the OhSoEz wiring diagrams from Dr. Rebuild for about $20 each. It's actually a pictorial wiring diagram that is very helpful. You can also get an actual wiring diagram from Lectric Limited, but it takes some time to become familiar with it. The wiring harnesses can be bought from Wilcox or Zip just to name a couple. The harnesses I installed were all built by Lectric Limited and they were a perfect fit.

On the other hand, you might replace the front headlight harness (it needs it anyway) and still have problems with some of the other lights because of a faulty headlight switch, or corroded connections where the fuse box passes thru the firewall. That's why I ended up replacing everything!

The previous owner of my car claimed he was an Electrical Engineer. I found bare wires, bare wires covered with duct tape, lots of extra little switches and resistors, and more than a few of those little crimp connectors. It's amazing this car didn't burn to the ground.

Hang in there, you have lots of support here!

John

 

You say that there are a lot of "blue wire splices", maybe one or more of these splices have a bad connection, either at the splice itself, or where the wires are connected. From what I have read on this forum, a lot of C3 owners have had problems with the headlight switch, including me. If the PO said that he/she was popping fuses, chances are you have a bad component, or an intermittent short to ground.
Be patient, you'll fix it eventually.

M2C Steve

 

Welcome and good luck with your new project. I suggest you get some manuals. Harnesses are all available from the aftermarket suppliers. I would recommend Lectric Limited wiring, you can buy direct from them or check out the other suppliers some of them sell LL as well, just find the best price. I would also recommend from Doc. Rebuild the oOSOEZ wiring diagrams for your car, they are cheap, laminated and show the actual photo of the connectors as well as the wire size and color, check them out, they are the best.

 

[QUOTE=JohnRR;1578859678]Welcome to the forum. You'll find lots of high quality advice here. I have a '73 that sounds a lot like yours. I have since installed all new wiring from bumper to bumper and now everything works Lucky for you, the front headlight wiring harness is available from several of the forum sponsors and is also one of the easiest to install. I strongly suggest that you buy the OhSoEz wiring diagrams from Dr. Rebuild for about $20 each. It's actually a pictorial wiring diagram that is very helpful. You can also get an actual wiring diagram from Lectric Limited, but it takes some time to become familiar with it. The wiring harnesses can be bought from Wilcox or Zip just to name a couple. The harnesses I installed were all built by Lectric Limited and they were a perfect fit.

On the other hand, you might replace the front headlight harness (it needs it anyway) and still have problems with some of the other lights because of a faulty headlight switch, or corroded connections where the fuse box passes thru the firewall. That's why I ended up replacing everything!


Are there any wiring harness available with the newer style spade fuses rather than the oem type?

 

I tried a few new fuses, as some said that a crusty fuse was the culprit, but no luck. I guess my next thing will be the headlight switch, but from what I hear, it's not an easy fix... I just see this being a can of worms already...

Is there any grounds I should check first?? If so, where would they be located?

 

There are numerous grounds all over your vette, best you get an AIM manual, it will show you all the pics. Or someone here might be able to post the AIM ground pics for you.

 

This is a good reccomendation. Grounds are most always the easiest thing to check right off the bat. From there, you're absolutely right, it can be a can of worms. I know firsthand how frustrating working with a clapped-out-hacked on wiring harness can be!


Worst comes to worse, remember, there are many pre-made harnesses made for your car specifically!

Wecome to the forum!

 

So, the ghosts continue.

I took the Vette out today for it's first wash. When I put it away, the interior lights now stay on...... So I have no dash lights, no running lights and the interior lights stay on... A few gentle taps on the dash around the light switch worked, and the lights went out..... But still no running lights...

I am really hoping it's just a switch..... Even though it's a little PIA, it's better than a new wiring harness....

 

Here's a schematic for your 74...
http://www.nrjvette.com/johdotukset/...tte%201974.pdf

No Parking Lights:
It looks like the RED wire brings power to the headlight switch and the BROWN sends power to the parking lights, you might see if one of the spliced wires came loose on the brown wire.
The ground for the front lights is on the radiator support on the passengers side you can check that also.

Turning the headlight switch **** full CCW turns on the interior lights make sure it's turned a little CW.

Post back your progress and someone will help.

Regards,
Pete.

 

Well, I seemed to have fixed the issue. Hopefully permanently, but I fear only temporarily. It was a blown fuse in the end. (helps when you pull the correct fuse......)

I still see a bunch of wire splices that I dont like... I also found an AMP hidden under the dash...

What I did notice is that the PO took out that reverse lights, and installed a second set of brake lights, which he spliced off of the original light socket.... Could this be putting to much draw on the circuit???

- Steve