First off, let me apologize if there is already something on this issue, but I could not see anything specific to mine... and, I hope I'm in the correct forum as I've never heard the term "Bullnose"!

My issue, as stated in the title of this thread, is that I do not have brake lights, REAR emergency flashers, or backup lights. I have the parking lights and turn signals on the rear, though. The flasher has been replaced and all of the fuses are good. The dash lights for the blinkers don't blink faster than normal indicating the bulbs are out, either.

For a little back history leading up to finding this... The truck had been sitting up for about 4 months due to not being able to easily locate a driver-side spindle for it. Before it went down, the catch on the turn signal cam broke, so I replaced it shortly after getting the spindle and front-end put back together.

I have not been able to find any information on the WorldWideWeb(www) that helps, either. So, any advice/help would greatly appreciated. And, again, I apologize if this has already been covered. Thank you.

 

I would think the turn signal switch. They all go through it. Also the ground. Find Gary's Garagemahal on this site. There is an EVTM for a 1981. He has a lot of info. on there.

 

These are all different circuits controlled by different devices.

But they ALL meet together at the LH rear, near the tail light area; this is where the harness that runs the length of the truck connects to the harness feeding the rear of the truck.

So, go nose around that area, maybe disassemble & clean stuff there.

 

Obvious question - automatic or manual transmission?

If the taillights and turn signals work, it's NOT the wiring at the rear. Hazards and brake lights do go through the multifunction switch, so def. check that. But reverse lights are separate from all of these.

 

I really appreciate the quick responses and will get out there in the morning and check for damaged or loose wires and connections. And, I have a C6 transmission (automatic).

 

The backup lights with a C6 are controlled by a switch on the side of the transmission.

Brake, turn signals, emergency flashers all use the same filaments in the bulbs, they are all controlled in the turn signal switch.

The front & running lights (aka parking lights), overhead markers if equipped, rear license plate illumination, all that stuff is one circuit on a dark brown wire.

Yes, Gary's site has EVTMs, choose the 1981 variant when you find it, it will be a tremendous help to you.

 

EVTM here:

1981 EVTM - ???Gary's Garagemahal


I'd suggest starting with the backup lights first. It's a much simpler circuit and not really related to the other faults. You could remove the connector from the transmission switch and jumper the contacts for troubleshooting. That would help rule out the switch.

For the other circuits that go through the turn switch: Do you still have the old switch? If only the external cam was damaged, you could plug in the old switch as a test without having to tear apart the column for replacement. Even with a new one, I'd plug it in first.

Also, be aware your truck has two flashers on the fuse panel. The exposed one, facing the driver, is for the turn signals. The hidden one, facing the firewall, is for the 4-way flashers.

When troubleshooting turn signals, I like to remove the flasher and jumper the contacts. This turns a fairly complicated circuit in a more straightforward one. It's much easier to check for power and ground without the flasher breaking the circuit.

 

TWO different flashers, both look identical as they are round with two prongs, but the 4 way flasher is a heavy duty unit, has a louder CLICK.

Parking aka running lamps located at the front, there are no rear parking (running) lamps. The rear has red lenses for tail/brake lamps, clear lenses for backup lamps.

 

My bad on saying they all go through the turn signal switch. Seen them called turnsignal/hazard switch. Sorry.

 

Yes, I know, Bill, but it takes too long to separate them when writing responses like this, he'll figure it out.

 

I used the term "parking lights" when mentioning what light/signals are operational and which are not... ALL in reference to the rear tail/brake/reverse lights. By "parking lights" I meant the rear tail lights are illuminated when I turn the headlights on. Edumicate me on the correct term and I will not slip up, again

Found my Neutral Safety switch covered in transmission fluid, so that could be part of it. It had a small leak before I had to park it due to the spindle, but it never quit on me. I was in the process of looking for the o-rings, but the parts house wasn't any help. I haven't made time to look into the brake and emergency flasher issue, so still on that.

 

Dude... Heh...

The rear tail light lens on these things use a single bulb inside to perform both functions...

1. Rear parking/running lamp circuit
2. Stop/turn circuit

Two entirely separate operations but sharing a single bulb, and the plastic lens envelopes (correct term?) both the rear & side of the body, which means no separate "marker lamps" or parking ights were used on the rear of these things.


So, there!

 

From the "You Probably Already Know This But Wanted To Be Sure" department, the single bulb has two filaments sharing a common ground. The stop/turn filament is brighter than the park/running lamp filament.

If only the dim parking filament is on, you will see the bulb get brighter when the stop/turn filament comes on.

If only the bright stop/turn filament is on, you will barely see any increase when the dim park filament comes on. It's easy to miss. This can lead to a misdiagnosis. I do not care to discuss how I know this.

The bulbs are keyed so they can only fit one way in the socket. However, I've found bulbs jammed in the wrong way, half a turn off, so watch out for that.

If there's a bad ground (dirty socket, for example), a dual filament bulb can cause all sorts of strange behavior. If the electrons can't find their intended ground, they will back feed through the circuit connected to the other filament. This can cause other locations to illuminate dimly. When troubleshooting a system with dual filament bulbs, I like to suggest trying the lights at night, away from street lights, etc. You may very well see other bulbs come on, but not bright enough to see in daylight. If so, you've probably got a bad ground somewhere.

 

It's funny, Karl, how you've brung up everything I want to say - yes, the sunlight can/will mess you up when diagnosing this kind of stuff, dimly-lit surrounding bulbs are a significant clue you need to be aware of when fixing this stuff. Like you said, ask me how I know.

 

Um, actually, I specifically said, "I don't care to discuss how I know this." Don't go asking me cuz I ain't admitting anything.

Besides, it wasn't me. It was a friend of mine. Yeah, that's the ticket...