Electrically this 71 is "Dead"

[vetteboy86]

Hey guys,

I was helping a buddy with his manual 71 over the weekend, he had some shifter issues, and we did a tune up on the car. After said work was completed we started the car and noticed the charge guage was fully to the discharge position. I wiggled some wires and it would jump back to charge and then go dead again. I wrote it off as a loose connection that we could find another day.

As we were working on the car, We had it jacked up so I didn't want to close the doors so naturally the buzzer was going off. That got old real quick so instead of disconnecting the batter, I actually found what I thought to be the device responsible for the buzzing, figured it to be a pizo or something. It was mounted on the driver side fender well and had several wires going into it. I disconnected it and the buzzing stopped. Well after I did that I soon realized that the interior lights were on so I decided to disconnect the battery. WIth the battery disconnected I reconnected the buzzer.

Well he called me today, and said when he tried to back it out of the garage, the charge guage smoked and the car basically is now dead. Wont crank, no headlights, no tail lights, no interior lights. He blames it on what I did, which I cannot confirm. I think it may have been a matter of time. Well anyways my question is does the whole car run through this guage?? If so is there a fusible link or something or does the guage need to be replaced??

Thanks

 

[vetteboy86]

Okay I talked to him again and I guess it isn't totally dead. The horn works, and the buzzer works, however not as one would expect. The key in the lock position with the door open the buzzer works, however when you turn it to run it stops, then turn the key to start and it starts buzzing again.

I think this is the least of my problems but just thought it might be useful information.

 

[Whiplash]

Can you give a little more of a description of the piece you disconnected originally? The horn relay is right in that area of the car and connects to the alternator, engine harness, battery etc and serves as the hot electrical nerve center of the car. If you disconnected this and didn't get it put together properly that could be the problem. The amp meters in these cars are very picky about having a good ground to them and that the major sources of electricity are connected properly.

Also, there is a buzzer in the fender area there as well. I have to confess that when I pulled the car apart I could never find this silly buzzer but when I put the car back together again it worked. Go figure. (mine sounds like a dying animal when it buzzes)

I'll pull my large wiring harness diagram out later tonight and see if I can trace the wires you disconnected if you can give me a little more detail. Wire color helps as well. Pictures are better yet.

 

[vetteboy86]

The piece I was looking at looked like a relay, but I was certain it was the buzzer. I removed a terminal that held two red wires. I can take a picture of what i disconnected tomorrow if you still require more info. How many wires go this relay, I know you have coil terminals and the three contacts, but are there wires doubled up, or any other distinguishing factor where I could tell if it was the horn relay??

 

[Whiplash]

The piece I was looking at looked like a relay, but I was certain it was the buzzer. I removed a terminal that held two red wires. I can take a picture of what i disconnected tomorrow if you still require more info. How many wires go this relay, I know you have coil terminals and the three contacts, but are there wires doubled up, or any other distinguishing factor where I could tell if it was the horn relay??

OK SAFETY FIRST. These cars have been known to burn to the ground due to electric fires when there is a major short. The smoke from the gauge was more likely smoke from melting/burning wires. I'd disconnect the batter NOW and then start checking for problems. I may be a bit of an alarmist but better safe than sorry.

Ok here's a pic of my engine compartment. You'll notice a relay on the top right of the picture where several red and orange wires are connected. This is the horn relay. If this is what you disconnected we know where the problem started and can work from there.

I'd also recommend you look under the dash and behind the gauge cluster in the center for signs of burnt wires. If there are any melted wires you'll probably need to/want to buy a new dash harness. It could also be as simple as a blown fuse from the starter to the relay. You can check the inline fuse to the starter by opening the white fuse holder on the red wire to the relay to check this fuse.

I'd inspect all wiring before replacing the fuse if blown to make sure there isn't a problem.

Others may want to chime in to help here. My car is at the paint shop so my reference point is memory, pictures, and a wiring diagram.

 

[vetteboy86]

Well that is good information, and will give me a starting point. I just dont understand how disconnecting this would create the problem. I was fairly careful hooking things back up. I only removed one terminal. Well keep the info coming and thanks again for the response.

 

[Whiplash]

So was the horn relay what you disconnected? If so do you remember which wire? This is where all the power to the car is distributed from the battery. The positive wire from the battery runs to the starter then a fused wire from the starter runs to the relay. The alternator also connects here. It's the hub for wiring for the whole car.

 

[vetteboy86]

With your help the problem is solved. I just couldn't sit here any longer so I went down and opened his garage and started looking. Everything was connected but not exactly in the way it came off, meaning the connectors are 30 years old and had some grime. I checked under the dash and so no signs of burnt wires, I think the smoke thing was a figment of his imagination. I took connections off once again and scraped them and put them back on making sure the retaining plate on the screw effectively clamped the wires in. The car woke up right away. I even took a ten minute drive with the top down. What a rush especially when the temp is 21 degrees. Thanks again!!!

 

[Whiplash]

Wow, that's great news! I'm glad it fixed things for you. Keep an eye on the amp meter. If you see funny things there you might want to go through the wires again.

 

[vetteboy86]

For sure, and thanks again