Hey guys,

I have and 1981 vette built in St. Louis before the move to KY. I'm restoring the interior at present replacing various missing parts, switches and ect.

However, I'm having some issues with several things that don't work, and most went out at the same time:

Power Locks
Horn (cap and horn components just rebuild in steering column)
Cruise control
Top light that shines down to light AC
Rear defogger
Power antena (this did work, but now does not)
Also factory radio did power up but nothing now
Lights for speedometer
Dome light
Cutesy lights
Make up mirror lights
new Headlight switch (headlights come on, but I have to open the vacuum valve under the steering wheal to open headlights

What is working:
headlights and tail lights, reverse lights, hazard, blinkers, side curb lights
lights in center gauge cluster above radio
gear indicator lights
AC fan motor and AC is cold
6 way adjustable seats
Power Windows

When I turn on the radio I hear a pop in the speakers and the "CB" light lights up but that's it....no sound or controls

Now....I'm new....but most of these things went out at the same time or very close...I would think it's something with a ground???? Odd that that many things would go wrong at the same time.....gotta be a common something???

Fuse box has good fuses....outside of taking it to a Vette shop....I'm stumped....I would really like to learn and explore

 

Most of what you listed are being run by the CTSY CLK fuse. Chances are ...either it is blown...or you have corrosion on the terminal(s) and the power is not making through the fuse and supplying the wire to power up these components. DO NOT use a test light...use a volt meter because I have encountered a circuit ( fuse) that allowed the test light to shine...but it only was allowing 7 volts ( for example) to make it to the components. Which will make it so it will not work.

It does take a special bulb for the light that shines down on your A/C controls. It is made where the end of the glass bulb looks like a magnifying glass...and it visibly thicker...versus a normal 194 bulb.

You dash lights are powered when you pull the ****...and it supplies voltage to the fuse in the fuse panel which I believe is a 7.5 amp fuse at the top of the fuse panel.

DUB

 

THANKS DUB!!! Great info...I'm learning a lot.

Here's what I did:

Got a volt meter and tested on the battery poles....13 volts on the money...good to go there!

While underneath the dash, I pulled the 20 amp CTSY CLK fuse and guess what....it was popped! I put a meter on con and tested those contacts...got tone, which means 13 volts is running across! Replaced that one with a new one...and then I thought, "Why not replace all while I'm under here...so I did!

However...not much changed except I now have fully functioning dome lights and the cigarette lighter works! No horn, no locks, no defogger, no instrument lights over the speedo and tach, and the AC area light is still not energized....ideas?

I have not tested the radio / power antenna yet because no radio is present.

Ideas from the senior electronic gurus???

 

Just had one the other day, those fuse blocks are famous for steel grips holding the fuses, and over the years/decades they corrode and get hot on the ends of the fuses, melting the internal soldered junction from the silver tips to the internal fuse link, the fuse LOOKS normal in some instances, but may well come apart when you go to pull it outta there....



BTDT, several dozen times over the decades....

 

Thanks guys for all the info! Here's the update on what now is working:

Replaced ALL fuses with new fuses.
Fuse box seems to be in good working order.

1. Dome Lights now work.
2. Courtesy Lights all work with timer. (Even spare tire light....a cool feature I did not even know it had!)
3. Cigarette lighter works and has power! Get hot...perfect!
4. New Radio and speakers...working perfectly!
5. Power Ant. now working with power supplied by new Radio.
6. Put old switch back in.....lights now work and raise properly with vacuum, ect.

CELEBRATING THESE ACCOMPLISHMENTS!!! I'M LEARNING SO MUCH!!!

Now....things that still DO NOT work....




POWER LOCKS - Pulled switches and they look corroded! So, I'll change them. Power is good to the pigtails...switches?

HORN (cap and horn components just rebuild in steering column)...still not working....found horn in driver's side fender well...green wire is not attached, but no power on green wire...a real mystery here....ideas?

CRUISE CONTROL - Where do I start???
Top light that shines down to light AC - another mystery with fuses being replaced....have NOT checked power.

REAR DEFOGGER - power is good to the switch connector....bad switch???

LIGHTS FOR SPEEDOMETER AND TACH - THE BIGGEST MYSTERY OF ALL....SUPER FRUSTRATING....power is good to the PC. Brake, high beams and turn signals all working.....NO LIGHTS FOR THE GAUGES...I'm at a lose!

Make up mirror lights...power is begging supplied on the line.....new mirror lights?

 

bump

 

I have an 81 and have fixed almost every electrical circuit in the car. My harness must look like a mess of splices. In general, if lots of stuff is acting funny I would check for solid grounds. I don't have the wiring diagram in front of me so I don't know if all these circuits have common grounds. Check as many as possible. A rusty ground nut can cause all sorts of weird behavior. Do you have a circuit diagram? If not , get one, there are plenty of people on here who can help you troubleshoot the circuits one at a time.
The 81 service manual has great diagrams of each circuit. Well worth the investment. Good luck, be persistent, solve one problem at a time

Power locks, Both switches have to work for either one to work. If the switches and are corroded, clean and/or replace. Lock switches without the word "lock" only cost $10

Light on ac is simple, 12 v to a light bulb. Look for the ground

Cruise control is pretty complicated, there are electrics and vacuum that has to work. Are all the vacuum lines working, there is one that goes to the brake that turns off the servo when you tap the brake

Cluster lights - look for the ground