Ok I am still trying to tackle the problem with my headlight and turn signal, let me give you the run down. Everything works fine with the passanger side turn signal until I turn on my headlights, the front and back will not come on at the time the headlights are on, but once they go off, the turn signal comes right back on. Here is what all has been done to try to fix it

new light bulb
new light socket
checked and cleaned all grounds
checked wiring from lights to the front of the cab
changed both flasher units
tried like two different turn signal selector inside the steering column
rewired some of the front flasher
changed ends on the headlight

What else can be fixed

I got a little idea earlier I unhooked both sides and switched them around I put the left side on the right and vise versa, and the passanger side worked becasue it was hooked into the drivers side, but the drivers side didnt work becasue it was hooked into the passanger side, so I am ruling out the socket and wiring after where it connects together. I am suspecting two things, the wiring from where it connects to where it goes into the cab and it goes right where the heater unit is inside, and I am hoping to not have to rip that out. I really hope I can fix this thing because I want to get it on the road finally. Do you think it could be the turn signal selector in the column because the thing if totally differnet from the way it use to be, from when I changed my column, it use to be a column shift but I changed it I got a column out of a 1978 truck and the unit inside the column was bigger then the origional. There is also one more wire within the new selector but I am really not suspecting that to be it. Well hopefully I explained it enough to be able to get some help. Thanks a bunch.

 

You still have a ground problem.

 

How many grounds should I be looking for, I know of two, I sanded and cleaned up both, wha else should I do to the area to fix it?

 

I also need to add, we changed the socket before which the bulb didnt fit right and if you turn the lights and turn signal on and wiggle and fudge with the light you sometimes could get it to work, but with the light socket not locking the bulb in we got a new one a metel socket and we cant get it to do anything now, I am using 1157 bulbs which is what it calls for.

 

There's a ground at each Tail light, parking light and headlight. Sometimes you just have to buy a new parking light or tail light assembly.
I tried resoldering one on my 78, didn't work well, bought a replacement from NAPA and the problems went away.
These old trucks get a lot of road crud up in the lights area. It eats away at the wire connections and the ground assembly, as well as corroding the metal under the ground terminal.

Turn signal works till headlights are turned on?
Did you check to see if the Headlights glow when the TS is blinking?
What your describing is "Not enough current flow to do both" which is either a Bad connection from the 12V source, or a Bad ground.
It sounds like your turn signals are grounding through the headlight filament.
DId you have to make any solder connections?
How about them dreaded 'twisted together' connections? Any of them?
If so, splice in some good Butt connectors.

I couldn't follow your swapping event.

 

Another day no success.

here is what we did today to try to fix

We made seperate grounds for the headlight to the frame and a ground for the side light to the radiator support and the turn signal to the radiator support. Someone told me it might be the circuit behind the instrument panel, could it be?

Today we checked out that if you tun on the headlights and turn on the four ways both sides work fine, its still only happening when you have the headlight on and try to make a right turn. We used thoses dreaded connectors when we wired it, We did no soldering

What do you mean about the swapping event, about when i crisscrossed the wires I made it when you click on the turn signal to the left the right signal comes on and by doing that it made the drivers side not work because it was plugged into the passanger side. Also When I got mad I kicked around by the door hinge and it worked for like 3 blinks then went back off. I am about ready to give up soon if I cant figure it out. I have done alot with the grounding, where else can I check for grounding, anything under the dahs I should look for? thanks for the help.

 

Your turn signals are finding their ground thru the headlight circuit. You should have a body ground, frame ground, and an engine ground. The body grounds often go bad when body panels loose continuity because of rust. Sometimes running a bond wire between panels is required.

 

Probably stupid question but...

Since you say the turn signals work without the headlamps on, it seems you have a short between the two systems.

Does the problem only happen with the headlamps on? or is it actually when the parking lamps are on? The harnesses for the turn signals include wires and shares grounds with the parking lamps. Possibly the two circuts are shorted together. The parking lamps dont flash, but has 12v the same as the turn signals. Would keep them from flashing.

If the front stops only, then the short is in the front of the truck, possibly in the harness between the firewall and the lamps if not the lamp sockets etc. Or main harness in the cab.

If it affects both front and back, the problem would be more likely in the back of the truck. Possibly in the chassis harness that runs along the frame, or the rear harness that runs along the back. Also could be a short in the main harness, and/or Could also indicate a bad turn signal switch, but the headlamps and turn signal switches are not connected so I doubt that the switch is your problem.

The front and back turn signals are isolated from each other through the brake light switch, and turn signal switches. Keeps your front lights from turning on when the brakes are applied, and lets the back turn signal operate when the brakes applied only on the activated side. Additionally your emergency flasher circut bridges the gap between front and back turn signals, and also left and right, and when you step on the brakes all four will burn steady, front and back. etc...

A few problems that can cause your particular problem, and hopefully a few solutions.

The first cause I would check is a short between the Parking light circut and the turn signal brake light circuts on the chassis harness, and rear harness. Remove the harnesses from the truck and check for continuity between the wires, and check for shorts between each wires in the harness. If you find a problem, with continuity, or a short between two wires, unwrap your harness remove the "black tape" around it, and look for the signs of the problem. Wires rubbing along the frame, melted together etc. Use a good crimp, or my preference soldier the wires, and use shrink tubing. When the repair is done, rewrap the harness with black tape.

Did you check the 1157 light bulbs themselves?
Sometimes a filiment breaks in the bulbs and crosses with the other creating a short circut.

Have you checked your body and chassis grounds? One goes from the Engine to the Firewall. One goes from the battery Neg side to the chassis and engine. One grounds the hood. If those grounds are bad, that can cause bad grounds at all your new ground wires... etc... Doubtful with your symptoms but you never know.


When you turn on your hazzard flashers, does all the turn signals flash? Even with the headlamps on? Could indicate a bad ground on the side that doesn't work. When you use the emergency flashers, all the turn signal circuts, front to back left to right are connected, Also, does it still flash when the brakes are applied? It shouldn't. Could indicate a problem with the brake light switch, or hazzard flasher components.

Hope this helps you out.

 

Check the Read First: FAQ thread at the top of this page for more information and resources.

 

Try disconnecting the sub-harness for the lighting. If yours is the same as my 78, you will have a ring connector that is grounded at the core support. Look at the socket for the turn signal/parking light. You should have three wires. The black one is the ground.
Check it with a meter, you should have continuity between it and the ring terminal. Also check the black wire at the plug for your headlites. It should also have continuity with the ground terminal. There is also a square rubber connector that plugs into your main harness, it has four wires. Once again, check the black wire for continuity with the ground terminal. It looks like there is a 4-way splice in that sub-harness. Maybe that's where your problem. Or not! Anyway, Good Luck!

 

Instead of doing all that swapping, which may add another dimention or two to your porblem, put it all back the way its supposed to be.

Then (assuming the left TS is the problem) go to the front and rear sockets, and verify the TS Socket is grounded. When the TS is on, and working, lift the ground and see if it continues to work. Do the same at the rear.
I think that's where the problem is.
The current is flowing through the parking light and TS filaments, (no ground there) and then back through the wires to the Light switch, and from the light switch, through the Headlight filament and to the head light ground.

verify all that by turning on the TS at night, and seeing the slight glow in the headlights.

You should have this fixed in a couple hours.

 

Ok i Will try that, also the filiment does light up when its turned on, someone looked at it and also said that, I got a volt meter today and put it in the socket, one of the 2 metel things inside it gets enough juice but the other one dont get very much, they both flash with the turn signal also, is it suppost to do that?Could it be any chance that its my turn signal switch in the steering column doing it? I put a new column in it out of a 1978 truck which mine is a 1976 would the wiring off of the 1978 turn signal switch be different than the one origional out of it, because the one origionally out of it was different looking than the one i just put in it, but everything wired up ok on it.

I will tyr puttig it all back together and check all the grounds out again. If I lift the ground it shouldnt come on anymore should it?
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The current is flowing through the parking light and TS filaments, (no ground there) and then back through the wires to the Light switch, and from the light switch, through the Headlight filament and to the head light ground.
------------------------Im not really understanding it, should i put a ground for all three lights on the passanger side or put them all into one ground.

 

I think that's where the problem is.
The current is flowing through the parking light and TS filaments, (no ground there) and then back through the wires to the Light switch, and from the light switch, through the Headlight filament and to the head light ground.


That what it is doing exactlly, how can that be fixed to make it work, do I need to fix grounds, How should the grounds be hooked up PROPERLLY?

 

Ok. glad that it's narrowed down

Check the grounds on the front of the truck and then the back of truck, from the turn signal + parking lamps for continuity from the ground wire, to the lamp sockets ground. I'll bet there is a break in the ground wire there, somewhere, or really bad corroded lamp sockets. You may need to replace your lamp sockets.

Also check to see if the bed of the truck is still grounded on the bad side. use a trouble light to test. If it doesn't light when grounded to the bed, run a ground strap "wire" from the frame to the bed of truck on the "bad" side.

hope this helps.

 

I had a problem very similar to this about a year ago. Some ALL four turn signal sockets were bad at the same time.

I checked everything that I could think of, it was driving me insane. Then someone suggested that I replace all of the sockets. I did and viola, they all worked. Its eemed that every socket was corroded inside not allowing a proper return to ground. Heck, my tail lights didn't work half of the time.