Hello,
I have searched for an answer to this but have not found it yet. I recently restored my 1984 corvette, and all of my lights worked.

I was told today that my tail lights were out and my marker lights were out, also my digital dash seemed dim and my shift plate light was out along with the heater control and radio. If I pressed on my brake pedal slightly everything came on. My headlights worked along with my fog lights before I pressed the pedal. All of the fuses in my fuse panel are fine and not burned out.

Not really sure where to start so any help would be greatly appreciated!

Thanks.

 

I would check grounding connections, you'll need a FSM and/or wiring diagram to locate them. Or, there could be a loose connector in the vicinity of the brake pedal linkage.

 

Okay I will try that out once this rain decides to leave. Thanks steve!

 

Yes, a bad ground will cause this crazy malfunction. The first place to look is the ground for the rear lights. According to my '84 Electrical Shop Manual, this is located behind the right panel in the hatch area, just below the right hand hatch support strut rod. One way to check for a bad ground is to measure the voltage on the outside shell of a rear light bulb socket. With the parking lights on, this should be zero volts (ground). If this measures anything above about 2 volts, you have a bad ground. Since the tail lights are hard to get at, check this at the right hand rear marker lamp.

P.S. Please send us some of that rain.

 

Thanks fellas, had some pretty nasty looking ground wires, cleaned them all up that I could find and get to.

P.S. Roy you can have some of this rain!

 

So, did that solve your problem?

 

Yes it sure did Steve, some pretty nasty looking ground wires. Cleaned them up good with a wire brush and the contact points and the lights turned on with no issues! Thanks again

 

Alright here's a twist for you two in case you know anything more. Cleaned the ground wires and everything worked. Turned my lights on, got home and noticed all the lights were out again, checked the fuse and it was blown. I put in a new fuse tried again and it was blown again. Through all of this my left turn signal has never worked and my right turn signal WAS working but now it seems to just stay on solid. Any ideas?

 

A blown fuse normally means an overload in the circuit. If the fuse is the correct amperage, look for a short to ground somewhere in the circuit. A ground-side problem will not blow a fuse, the circuit just won't work properly.

The turn-signal symptoms may have multiple causes. A turn signal that doesn't blink points to a burned-out flasher. The left side could have burned-out bulbs or corroded contacts in the sockets.

Some points to remember- the rear turn signals and brake lights use the same elements in the bulbs, so a bulb problem will affect both. Also, a bulb is actually a controlled path to ground, although an inefficient one, so supplying power to a bulb completes the circuit, and the circuit can be affected elsewhere.

Troubleshooting involves isolating a single culprit. The turn signal/brake light circuit is complicated, including the turn signal lever, 4-way flashers, and brake light switch as well as the wiring, etc. There are many places that could cause trouble. You could try the 4-way flasher switch to see what happens or doesn't happen. Of course, make sure the fuses are the correct amperage. You could also check the various bulb sockets for corrosion and good contacts.

If you plan to keep this car, I suggest you get a year-specific Factory (or, Field) Service Manual, written by GM and published by Helms. This is the bible that the dealers use, and it has a ton of info about every aspect of the car. Don't waste your money on Clymer's, Chilton's, or other generic books. At the very least, seek out a 1984 wiring diagram (which is in the FSM) so you can trace the circuits.

 

Thank you all. I'm a third shift worker, and really didn't fill in all details, sorry. Here 's the scoop. Upon restoration, I purchased all new bulbs for every socket, and made sure they were the correct number for each socket. I have a factory service manual, electrical and parts manual, so I'm set, even though the SM leaves a lot to be desired. There's more knowledge here than the manual's supply.
The original problem was no tail lights, side marker lights, right turn signal comes on, doesn't blink, but you can hear the relay working. The left turn signal works if you wiggle the turn signal arm sometimes, but never stays on. No instrument cluster illumination unless you depress the break pedal.
I cleaned all grounds as recommended then found the fuse for the tail lights was bad. I needed a meter to tell, because there's only a small barley noticeable black spot on the fuse wire, the fuse looked good! but wasn't.
Replaced the tail light fuse, had tail lights and marker lights, but the turn signals still malfunctioned. It seemed like the right turn signal worked for a while, then stopped blinking, even though you can hear the turn signal relay work. The left turn signal never worked, still had the same condition as before.
Noticed that the tail lights weren't working, and the fuse was blown again.
I have a new turn signal switch I plan on installing, will probably replace the flasher relay to be proactive.
As mentioned I have cleaned all ground connections, and believe this fixed my instrument cluster problem, since they now come on.
I'm also thinking there may be a problem with the break switch also.

HotRodRoy, hope you get the rain, thanks.

 

The wiggle in your turn signal switch points to that as part of your problem.

Remember, the operation of the brake lights goes through the turn signal switch. Just in case you were not privy to that piece of information.

I believe you are on the right track!

 

Thanks Torch! I work the next 3 days but hope to be able to try some more digging and eliminating 1 thing at a time!

 

Look at the headlite switch as well...everything has a path thru that switch and it can interrupt most lighting circuits.

 

You may wind up testing wires individually, with a continuity tester and/or voltmeter, to locate any opens or shorts to ground. Since you have the diagram, this may be somewhat time-consuming, but doable. If you do it one circuit at a time, you will likely be able to isolate any flaws in the wiring. Keep posting back re your findings, and the collective experience of CF may well be of help.

 

I would also check the sockets for the 1157 bulbs, the big turn signal bulbs. The ground contact on the socket can break off causing strange intermittent problems, on my '84 they did. I suppose a broken ground terminal floating around inside a socket could cause a short, too.

 

What I would do is, unfortunately a pain.
I would remove the bulbs from the turn and tail lights. then start at one corner of the car, and turn on the lights.
add a bulb to say the left outboard socket, check the fuse. If the fuse is good, wiggle all the wires I could get to, and then check the fuse again. If the fuse is good through all that, leave the first bulb in the socket, and add a bulb to the light next to it. wiggle all the wires and check the fuse agin. if good, move on to the next socket. And so on.
A lot of the time, if there is a wiring problem, with everything hooked up, sometimes the problem won't show unless you go over a bump, or bump and step on the brake, etc.
Just be patient, and the problem could even be a bad element in a bulb. You never know.

 

Is this a flood recovery car? You don't deserve to have this many problems. I've got 240,000 miles on my '84, and all my electrical stuff works fine! Do you know the history of your car?

 

i had a similar problem ('89), got pulled over twice for no tail lights...

check out ur front side turn signals and cornering lights for ground and corrosion in the bulb socket, every time i would hit my left turn signal i would blow the tail fuse, got some of the gunk out of the bulb sockets of those 4 lights and bam, working tail lights again! (had turn signals unplugged for months under the driver dash, finally got around to fixing it)

 

Hot Rod Roy, as far as I know it's not a flood recovery vehicle. Bought it having 80,000 miles on it from a fellow in Mass. who had bought it new in 84. When I bought it the only thing going for it was being mechanically strong.

Tuesday I spent some time getting the turn signal switch changed out, (the retainer clip broke so I'm waiting for a new one to come in to put the rest together.) I changed out the fuse for the tail lights and found out I could have the lights on until the battery would die and the tail lights would stay working. As soon as I turned on a turn signal the fuse would blow, and once I tried the hazard lights and the fuse REALLY went poof.

So it seems Dynamo had a very similar problem so I'll go out today and see what I can find with the sockets and go from there

 

You have a dead short to ground in the wiring associated with the brake lights (NOT tail/ running lights, this is a different circuit.) You should test the various wiring runs individually with an ohmmeter, a continuity tester, and/or a simple test light. Use your diagram to identify them. I'm betting you will find a bare spot in a wire that grounds the circuit and blows the fuse.