Wiring gremlin - Nothing works unless trans is in reverse

[Jgonick]

As far as cab lights, is there a common issue with them?

The courtesy light and dome light both use the white wire to provide a ground. White wire provides ground by the door jamb switches or by turning your headlight pull switch all the way to the left.

 

[Scottsdale87]

Turns out I had a couple of cut wires and got them fixed up. I have hazards, drivers side signals and brakes, but my passenger signals are non existent. One thing to note is my hazards have a faster paced, more normal “signal” where as it has a pretty long pause when I put my drivers side signal on. I would say a flasher could be the culprit. The joys of fixing an old farm truck!

 

[Scottsdale87]

The courtesy light and dome light both use the white wire to provide a ground. White wire provides ground by the door jamb switches or by turning your headlight pull switch all the way to the left.

Sorry, I meant clearance lights!

 

[Grit dog]

Man, how many squarebodys has @Edelbrock gotten his pea pickers and wire nuts on??

 

[Chevykid]

Also check your fusable links
And on the truck starting in reverse only check your adjustment on you ignition switch the one under the dash

 

[Sad Sack]

Man, how many squarebodys has @Edelbrock gotten his pea pickers and wire nuts on??

Edelbrock has been quiet for a while. Hope all is well.

 

[Ricko1966]

Edelbrock has been quiet for a while. Hope all is well.

If you take a jumper cable and 2 sticks of butter,and put them in the glove box does anything change? There,do you feel better now?

 

[Scottsdale87]

Now another one for you guys…
When my key is on, ignition off, with the headlight switch on, my front left hand parks are nice and bright, but I have no front right hand marker lights. When my key is off and the signal switch is activated for the right hand signal lights, my park lamps finally come on with the left side. My signals and hazards work “fine”, I may need a new flasher, as the right side is dimmer and slower, but I am curious if this is a signal switch issue inside the column, a headlight switch problem, or another ground issue? Also to note, before this I had no right front signals. I sprayed and cleaned up the signal switch with contact cleaner and got them working, but no park lights as described above. Brand new incandescents.

I also fixed the clearance light issue. Both wires were severed where they came in under the dash, didn’t look like they had a grommet there from factory

 

[Ricko1966]

Now another one for you guys…
When my key is on, ignition off, with the headlight switch on, my front left hand parks are nice and bright, but I have no front right hand marker lights. When my key is off and the signal switch is activated for the right hand signal lights, my park lamps finally come on with the left side. My signals and hazards work “fine”, I may need a new flasher, as the right side is dimmer and slower, but I am curious if this is a signal switch issue inside the column, a headlight switch problem, or another ground issue? Also to note, before this I had no right front signals. I sprayed and cleaned up the signal switch with contact cleaner and got them working, but no park lights as described above. Brand new incandescents.

I also fixed the clearance light issue. Both wires were severed where they came in under the dash, didn’t look like they had a grommet there from factory

It's not the flasher, you have bad connection probably a dirty bulb socket. The slow flash is because of the extra resistance.

 

[Scottsdale87]

It's not the flasher, you have bad connection probably a dirty bulb socket. The slow flash is because of the extra resistance.

Got excited and went back out to the garage. Initial inspection of the socket was that it was fairly clean. I used some contact cleaner and cleaned out both right front sockets, wiped the contacts on the bulbs, and still no change unfortunately.

I will also mention that when the key is off and the signal switch is turned to the right signal, the park lamp is equally as bright one both sides.

 

[Ricko1966]

You still a bad connection whether it's a dirty ground or a dirty or bad contact in the turn signal switch etc. But you have extra resistance in right signal,check the rear socket too.

 

[Jgonick]

throwing this out there- make sure you have the correct bulb installed- the front turn signal/park lamp is a double filament bulb (same as brake lights) that can cause all sorts of strange problems if it is a wrong bulb or a filament is broken. - can be confusing to explain-but one of the filaments actually acts as a ground path.

I believe the bulb should be a 2057 (or 1157)-

 

[Jgonick]

When my key is off and the signal switch is activated for the right hand signal lights, my park lamps finally come on with the left side

My theory on what is happening- You are providing a ground path when you turn the turn signal on with the key off - Thus the park lights come on. The problem more than likely is a bad/wrong front turn signal bulb-or a bad ground at the front turn signal socket. The probable reason your blinkers work but blink slow & dim is because it is using another way to get to ground- (like the brn wire for park lights thru the left front park light to ground when they are off. )- Thus confirming bad bulb or ground.

So- 1st check front right turn signal bulb making sure it is good and correct-
2nd check ground at that socket.
3rd could be bad socket.

 

[Scottsdale87]

Thanks guys. After work just got a few parts on order, I have a new socket coming, along with both headlamp and signal switches. A brand new 1157 with a HD flasher just went and fixed my dim/slow signal light. But still having that same issue trying to get the front right hand parklamps to come on with just the headlight switch. As soon as the new socket comes in, I will get that wired up with a fresh ground, then proceed from there. Will keep you all updated!

 

[Broken85]

Do you have a wiring chart yet? Turn off the lights in the garage and go to the kitchen table and stare at it. To steal someone else quote here “plan the work and work the plan.” The wiring diagrams maybe daunting at first glance but eventually the GM engineers from 40 years past will start to speak to you. Seems like you are starting to get frustrated and starting to throw parts at it (like we have all done).

You probably have more than one bad ground or a bad ground and bad component preventing 12v which is tough to find,. It is entirely possible you could be replacing old, but good parts with new junk that doesn’t work which will increase your problems.

Every bulb gets a positive and a negative to work. Get a test light to look for the power and a multimeter for continuity for the ground and work from the bulb back. Your rear light; do you not have a ground or not have power or do you not have either?? You will get it. These guys will help.