what the? turn signal/park light

[layedout72]

alright...im absolutely confused here. When I turn the truck off, but put the turn signal on, (with lights turned on) I get the park light on the driver side to work. When I turn off the lights, crank the truck, and put the turn signal on, I get ....ta daaa a TURN SIGNAL! I cannot get my park light to work so long as the truck is running.Only the driver side does this, and the pass works fine. Both wired exactly the same.

[layedout72]

okay, switched the bulbs, and even tried a brand new one. it doesnt matter which side it is, the bulb just doesnt work.

[bluef250]

Turn signal switch has terminal disease and needs a life saving (for the truck) transplant???

[layedout72]

well, nevermind. its all working now. i dunno ??

[seattle67]

We electricians have learned not to question why things all the sudden start working, we just call it "FM" and move on. Of course we never admit to anyone else that it was "FM", we take full credit and chalk it up to our amazing trouble shooting skills.

Basically electricians are an insecure lot that live in constant confusion and terror of the mystical thing that the general public, in their blissful ignorance, call "electricity", but we call "silent death".

You tamed the beast for now, but know this, it WILL be back, and it will be very, very pissed off!

[wt4speed#2]

We electricians have learned not to question why things all the sudden start working, we just call it "FM" and move on. Of course we never admit to anyone else that it was "FM", we take full credit and chalk it up to our amazing trouble shooting skills.

Basically electricians are an insecure lot that live in constant confusion and terror of the mystical thing that the general public, in their blissful ignorance, call "electricity", but we call "silent death".

You tamed the beast for now, but know this, it WILL be back, and it will be very, very pissed off!

Hey Dan
I had to laugh, when some one asks me what I know about electricity, My standard reply has been for years."I know 2 things about "Electricity" 1) it turns on the lights 2) it will hurt you.

[seattle67]

Tony, with that knowledge you are ahead of 50% of the "electricians" out there, at least in the marine trade. Want to come work on some ships?

[19FORD67]

[AlleyCat]

We electricians have learned not to question why things all the sudden start working, we just call it "FM" and move on. Of course we never admit to anyone else that it was "FM", we take full credit and chalk it up to our amazing trouble shooting skills.

Basically electricians are an insecure lot that live in constant confusion and terror of the mystical thing that the general public, in their blissful ignorance, call "electricity", but we call "silent death".

You tamed the beast for now, but know this, it WILL be back, and it will be very, very pissed off!

Man I got to remember that line.

Recently I had the job of replacing a failed PTO on an auger truck.Not a bad job except the PTO grenaded while they were drilling a hole for an electric pole INSIDE a sub station.The electricians who were on the job told me I would be okay as long as I stayed away from the equipment.They didn't have to repeat it.

[Underdog97]

Having restored a lot of Ford Trucks and refurbished a ton of turn signal switches it sounds to me more like you have a grounding problem than a switch problem. This isn't uncommon for the 67 to 72 Ford trucks which have the tail lights grounded through the screws that hold the inner taillight buckets to the bed. one side has a ground and the other doesn't. I've fixed this problem by cleaning a spot on the inner tailight bucket that's not working and then attaching a new wire to it and running it directly to the frame where I bolt it for a good ground. Electricity will always take the path of least resistance and a backfeed can and often does occur, thus when your headlight switch is pulled it will act as the ground for the one light that you're having a problem with. As for it fixing itself it most likely has an intermittent grounding issue ( Not uncommon )!

[Rjames]

I have been having very similar problems with my 69 f100. When I bought the truck I drove it 2 hours home and it runs great. However, on the trip, the turn signals only worked once or twice. They have not worked since. I have replaced both flashers, the turn signal switch is brand new (thought that would fix it), and have brake lights, parking lights and emergency flashers. The only trouble is the turn signals.

I have power to the harness at the light blue wire, the fuse on the panel is good and registers power with the key on. I have also checked the four way connector on the inside of the fire wall.
The flasher on the right has power constantly, the one right behind the instrument panel does not, I have switched the flashers also and no luck (both new). I checked where the flashers go into the harness also, some had constant power (two I think) and a couple of others flashed power (even with turn signals off, although the tempo of the flash did change when I switched the turn signals on and off) .
As with most of you. I am getting frustrated to say the least.
Any suggestions? This is a Father \son project and would, for memory sake, like to do the work with just my son and I. Thanks in advance for your time.

Bob

[AlleyCat]

Hi Bob and welcome to the site.It sounds like you have a ground problem.Maybe more than one.I would start by looking at the wiring diagrams that you can find on the home page.Next I would look at the harness at each light.The tail light grounds go to the corner post of the bed on Styleside beds.The front parking light grounds are on the rad support.

[Rjames]

I have checked the grounds on the rear tail lights, at least I think that I have. I disconnected the rear tail grounds and the parking lights went out.
I just tried the signal switch out of my donor truck and it did not work either.
As for the schematics, I cannot make heads nor tails of it. It seems to me that there should be power to the column harness, when the lever is actuated, it should send power to another wire in the harness to activate the right or left signal, I cannot see any power other than the blue #2 wire in the switch harness.
The wiring to the rear tail lights and front lights looks intact and all connectors seem connected and in decent shape.
I think that I may be running out of "figure it out" because I have no idea what other grounds to check.
thanks for your input.

[Underdog97]

AlleyCat brings good advice. I would also clean the ground connections to rule out any possibility of this regardless of wether or not it looks like the problem, eventually it will become a problem and since you'll be looking at these anyway now would be the time to clean them. I also wouldn't rule out the turn signal switch itself even though it's brand new, I would also check the bulbs again. Are the 4 way flashers working, both on the dash and the outside of the truck? Did your new turn signal switch have the same colored wires as your original switche's wires. Some aftermarket switches are'nt color coded for the years but in general are a one switch fits all 67 to 72 Ford Truck.

[Underdog97]

Check your fuse box to make sure power is coming from it. The fuse may look good but it doesn't mean that the connection is there. I would turn the signals on and put a jumper wire across the ends of the fuse (briefly) just to check. The fuse holders in The Ford trucks have a tendency to get loose with age if they've ever overheated it could be the problem