I thought I might put a note out here while I continue to troubleshoot in the odd chance someone else has faced this same problem before. Lots to troubleshoot!

I have a 1980, not too long (months) ago frame off and painted, by a shop. In other words I didn't watch every nut and bolt or electrical connector get put back together. A risk...I know. It was in rough shape before going in, passed inspection, but it was tough to know if everything worked 100% as it should at that point. They didn't do anything significant with the interior, short of dropping the steering column and putting it back up during reassembly. Most of the rest of the interior was/is already out of the car other than the driver's seat, dash, and upper console. I'm going to tackle the interior redo myself. Been spending my time going over it little by little. Lots of little things to check, make sure of connections, clean and lube, etc., before I even get to the finishing touches.

I started with putting the side windows back in the doors and their reassembly. Moving right along, but started chasing around an issue with the power door locks, which has lead me to what I think might be a bigger issue. With a multimeter attached to the negative battery post, to help rule out grounding issues, I get 12V at the orange wire at the passenger side door lock connector, as it should be. However, when I go to the driver's side I get <1V, but certainly not 12V. I even pulled apart the connector going to the door in the footwell and get the same low voltage there. Also checked the cigarette lighter center post and I get the same <1V type reading. They're all on the courtesy/clock circuit. I don't have a blown fuse.

How can I be getting a lower voltage on basically the same wire? But not a blown fuse? Perhaps a corroded connector somewhere? The trouble is, by the wiring drawings I have seen, there are no connectors between the orange wire going to left door and right door other than the ones in the footwell. They look like they simply have a t-connection on the lead off the fuse box, which I'm betting is buried in a wrapped harness....somewhere, one going left the other right.

Like I said, I'm still digging, but thought I might ask in case anyone has chased this down before, or might know one of the more obvious places to look for issues at. At some point I will swap out the dash making all of those wires and vacuum lines more accessible at that time, but I was hoping to not have to do that quite so soon, assuming that'd even be where to continue looking.

I have also found some "bubba" electrical fixes already that I don't fully understand. Like someone ran a fused lead from the hot side of the A/C fuse, the wire pushed into the fuse block itself with the blade of the fuse, over to splice into the light green lead at the A/C heater switch connector in the center console. I have no idea why they would have done that. I'll add, the AC on this car doesn't currently work either, but that's a project for another day/month.

Man, these types of electrical issues are nearly impossible and can suck up entire weekends!

Thanks, Pete

 

Pete,
Looks like we're in the same boat. I also have a 1980 with electrical gremlins. Looked over my schematic but didn't see power door locks. Could that be something GM squeezed in towards the end of the 1980 production year? Sounds like there's a hot wire going to ground somewhere. I connected a test light between neg battery and neg battery cable and am in the process of isolating circuits until the light goes out. So far no luck.
Dave

 

Have you got 12 volts on both sides of the fuse holder?

 

Fuse box empty except for the two circuit breakers. All switches disconnected, speedo and gauge clusters out, Starter replaced with jumper to eliminate possibility of internal starter short. Alternator to starter disconnected at alternator. Test light on when I insert heater/choke fuse. Disconnect choke at carb, light still on. Disconnect heater/choke relay light out, replace with new relay, light on. The search continues.

Found the electric door lock schematic, was tucked away on the corner of another page like it is some kind of incedental addendum. Looks like the orange goe straight to the psngr side but the driver side goes into a connector that also runs to the dorr lock motors.

 

You need a better wiring diagram or a complete one. 1978 was the first model year for power door locks.

 

Just a quick item for you, The 80-82 Vette does not have a wire that runs from the alternator to the starter like the older Vettes do. The wire from the alternator runs straight back to the battery junction box mounted on the bulkhead by the battery. This wire does have a fusible link in it. Here is the harness and junction box that is used on the 80-82 Vettes.

 

Thanks for this info. Have been crawling all over this car and haven't seen anything that looks like that. Will look for it or at lest evidence of where it once was.

 

It is mounted inside the battery compartment, just to the left of the battery on the battery compartment wall. This is the factory location.

 

There is nothing like that in my battery compartment, not even sighns that it was once there. Do you have any ideas

 

Look close at the wall where the junction box should be mounted, is there not a couple of small holes there for the mounting bolts? Do you have a large red wire running through a grommet just to the left and to the front of the battery? Post a picture of the battery area if you can.

Yes the bad thing about 40 year old wiring is this issues it can have. My 81 was a very clean car but after I pulled all the wiring and saw how corroded some of it was, I was glad I replaced every harness in it. Not cheap but I know that I am not going to deal with 40 year old wiring or electrical issues resulting from it.

 

If you are still looking for help, the wiring diagram at this site has the door lock switch circuit for 1980:

http://wordpress.keystonestatecorvet...m/?page_id=118

Here's another 80 battery compartment photo. There are plenty of other ways to run the alternator, though, so perhaps a PO has rewired it correctly, just different than stock. Please post some photos!

 

Well, we kind of got side tracked a little bit. Back to the original problem: Fuse box empty except for the two circuit breakers. All switches disconnected, speedo and gauge clusters out, Starter replaced with jumper to eliminate possibility of internal starter short. Alternator to starter/battery disconnected at alternator. Test light on when I insert heater/choke fuse. Disconnect choke at carb, light still on. Disconnect heater/choke relay light out, replace with new relay, light on. Tracked this down to the "I" wire going to the alternator. Disconnect this wire and test light goes out. Does this mean there is a short inside the alternator?

 

Your actual question might have gotten lost in your first post. You can edit it to put the main point at the beginning and end, and perhaps get better advice.

It is not uncommon for an alternator diode to fail and cause a short. What is the "I" wire? A photo or three might help us understand what you are doing and seeing.

 

There are two wires marked I and V that plug into the alternator. I thought I was the ignition light and v was the volt meter..

 

did you ever figure this out? im workin g on an 82 CE and im having isssues with dash lights. just replaced the pcb

 

It seems the alternator wiring was the culprit. Replaced with one wire alternator and no more short. Apologies for not publishing resolution until now.

 

The '80 has 2 wires running to the alternator from the fusible links "A&B" at the starter power lug. I have no idea why anyone doubts that. It is shown on the wiring diagrams Page 8A-11 of the factory service manual "Power Distribution Charging Circuit". Connected to both field current and output current at the alternator.

Also shown on page 8A-9 of the same manual "Power Distribution - Light Switch" So they also are feeding the instrument panel and ignition switch on an '80 for sure. Not sure about an '82 though.

I have been in there this week cleaning up some connections. They are there.

 

I believe only the car's that was equipped with a digitally tune radio had the wires running from the alternator straight back to the battery.

 

The charging lug from the alternator runs straight back to a terminal block and from the terminal block to the battery itself on the 80-82 cars. There is a stand alone harness made specifically for the 80-82 cars. See picture below. There are two fusible links down by the starter positive lug. These wires supply current back to the fuse block. All the 80-82 used this stand alone harness. The factory manual is not exactly correct on how the circuit actual is. Found this out while working on my two 81's I had.

There are different under hood harnesses and dash harnesses for the 80-82 cars depending on if the cars had the ETR radio or the analog radios and also for the manual or automatic cars.