Turn signal/parking light question

[bad67f100]

Sorry to ask because I am sure this is a common question. I bought my 1967 Ford f100 2wd short bed about 3 weeks ago. All the lights worked and signals all worked. I noticed that my passenger headlight looked weird when I had them on. I ordered the newer style headlights from LMC that have the replaceable bulbs and also the heavy duty headlight harness. When I removed the headlights, I noticed that the passenger headlight plug had the wires cut and wires were taped together and the colors of the wires were hooked up to other colored wires. There was one wire just hanging in there. I hooked the wires back up on the headlight plug back to correct wires(from what I could tell) then installed the heavy duty harness. Headlights work great now and both are same brightness. But now my front parking lights do NOT work at all and none of the turn signals work at all. Rear taillights light up when head lights are on but no signals. Driver side wiring was fine. My blinkers blinked real slow before so I am guessing thats why someone messed with the wiring. If i remeber correctly there was a red with black stripe wire, green with black stripe and ground wire. I hooked the green to green and red to red. There were actually 2 green wires and i tied them together and then connected them to the one green wire off main harness. Can anyone maybe post a pic of the passenger side headlight plug with wires shown? Maybe I can see if I hooked something up wrong. Thanks!!

[bad67f100]

So after looking at the wiring diagram for the headlight and turn signal circuit...it appears that the headlight has 2 ground wires that come out of the headlight bulb socket? One that grounds to the turn signal housing and one that grounds to area behind headlight cup? I have a ground going to the headlight cup but no ground wire from plug to turn signal housing. On my passenger side headlight plug it has 4 wires coming out of it...2 green and black and 1 ground and one red with black...not really sure what is the correct setup. Cant seem to find any pictures of the headlight sockets online anywhere that actually show the wires and how they are routed. Kind of lost at this point.

[basketcase0302]

bad67f100 » Thu Apr 21, 2016 8:53 pm

So after looking at the wiring diagram for the headlight and turn signal circuit...it appears that the headlight has 2 ground wires that come out of the headlight bulb socket? One that grounds to the turn signal housing and one that grounds to area behind headlight cup? I have a ground going to the headlight cup but no ground wire from plug to turn signal housing. On my passenger side headlight plug it has 4 wires coming out of it...2 green and black and 1 ground and one red with black...not really sure what is the correct setup. Cant seem to find any pictures of the headlight sockets online anywhere that actually show the wires and how they are routed. Kind of lost at this point.

Not possible for the headlight to work as you described how you wired it back together. The headlight harness / socket that plugs onto the bulb has to have one terminal for low beam / one terminal for high beam / and one terminal for ground for the bulb to work properly. When you tied two of them into the ground your adding a load onto the wiring harness causing the other symptoms. Also typically when any newer type bulb, (other than the crappy dim replacement bulbs gotten for our trucks) pulls too many amps for the 40 year old wiring to handle-which will in return leave you with dimly lit light even with the newer bulbs. The headlight relay upgrade, (mainly the larger wiring of it) that most here have done (and build it yourself with low cost ebay parts-don't wast money on a "one size fits all" headlight upgrade) is always a win-win for headlight issues with our older Ford trucks. Not that hard to do and the single biggest investment into your truck you'll always appreciate IMO.
Hope it helps...

[bad67f100]

Well I hooked up the green and black wire to the other green and black and red and black to red and black and then grounded the light. Headlights work fine. I also installed the heavy duty harness. Only thing is all.my signal lights and brake lights worked fine before I fixed the headlight wiring. The previous owner had rigged te headlight wires up on the passenger side. Now I have no turn signals or brake lights. All wires are hooked up correctly. Weird thing is my passenger side headlight connector has 2 green with black stripe wires on it plus the red with black and one black ground wire.

[bad67f100]

Well got everything working...feel stupid . It was a blown fuse. But the original 20A fuse in the fuse block was rusted so the original owner by passed that with a inline fuse that I didn't know about. It was blown but good now and all is working .

[basketcase0302]

Glad you got it all working. Wiring on our trucks can be a pain in the butt at times-real nice when it's an easy fix.

[bad67f100]

Ok I have all parking lights, headlights, and turn signals working except for my front right turn signal. It lights up for parking light but no signal. Rear works fine and hazard flashers don't work in front at all. Rear flashers do though. I've checked and everyting is hooked up...could this be a ground issue? Any ideas? Thanks

[basketcase0302]

Do you have a voltage meter, (or even a simple 12 V test light will work for this) that you can check for power at the socket there where it plugs into the parking light assembly?
Go backwards from there to the firewall / then to the turn signal switch and emergency flasher switch (which is more often than not an issue on our older trucks).

[bad67f100]

Ok thanks!