Headlight Question?

[Slofarmtruck]

I have a very simple question that I need help with. My recently bought 86 headlights don't work. Now my question is, on the quad headlights, which lights are the standard headlights and which ones are the high beams? for example: Are the upper set the high beams? I ask because it looks like the previous owner may have installed the incorrect bulbs in one of the locations, the bulb has 3 prongs on it for the harness and my harness only has 2 prongs whereas the upper bulb and harness both have 3 prongs. I really hope that makes sense. I just want to get the basics correct before I begin chasing a wire fault.

[Stitch]

the upper lights are the low beams...they should have a three prong connector because they have the wire for the low beams, ground, and high beams...they should come on when the high beams (lower lights) come on also...

on a side note, my lights worked intermittently all of a sudden a while ago...I looked at the headlight switch and it was the culprit...I replaced the switch, but the connector had gotten so hot that it had melted, so I had to replace it also...I live in the country, so I was riding around with my high beams on alot...the current for the headlights goes through the switch...all the current was what melted the connector...I solved that problem by putting relays in line with the switch...so that the headlight switch turned the relays on...added extra benefit is that the headlights are quite a bit brighter...

[Slofarmtruck]

I saw the relay write up and will be doing that once I have the lights working as they should. Thanks alot for the info. Funny thing is the lights worked for a second and it appears that the previous owner may have "for some odd reason" plowed with this truck as there is a Western Plow sticker on the lower dash for headlights/plow lights. The switch is gone and there are some wires hanging under the dash. I will look into the headlight switch as possible culprit!

[Slofarmtruck]

Ok did some trouble shooting today, and I have no power going to the headlights. I replaced the headlight switch since it is cheap security. I cleaned up all my grounds and if I run a power wire from the battery to the headlights they will go on now. Every other light on the truck works but the headlights. Both low and high beams do not come on. I have a pretty good idea on where to go next but wanted to get some clarification first. My questions are...

Is there a fuse or relay for the headlights themselves?

The truck had some aftermarket cruise system on it that was tucked up under the steering column. When I was playing with the turn signal/cruise/high beam switch a few days ago, I had headlights for a second. So this leads me to believe that my high beam switch is faulty or has a bad connection. My windshield wipers also only work on high and do not "home" themselves when turned off.

Does the low beam signal go through this high beam switch?

How does the column come apart? Do I need to remove the steering wheel to do so?

Worst case, I know I can run my own relays via remote switches to activate the headlights and high beams. Just hoping to do it all via the stock components.

Thanks again for any and all help. This is my last major repair before this truck is officially back on the road after 10 years.

[Stitch]

I would check to see if there is power going to the switch and coming from the switch...I'm pretty sure that the low beam goes through the high beam switch...so I would check to make sure there is power going to and coming from the headlight switch also...you said there were wires hanging under the dash, maybe the po cut part of the harness that is associated with the headlights...there is some kind of short between the fuse box and the headlight switch or between the headlight switch and the highbeam switch or between the high beam switch and the headlights...you just need to get a test light or voltmeter and figure out where...once you do some more trouble shooting where there's power and where there isn't power, you'll have a good idea of what you need to replace or fix

[Slofarmtruck]

Originally Posted by Fat Hoe

I would check to see if there is power going to the switch and coming from the switch...I'm pretty sure that the low beam goes through the high beam switch...so I would check to make sure there is power going to and coming from the headlight switch also...you said there were wires hanging under the dash, maybe the po cut part of the harness that is associated with the headlights...there is some kind of short between the fuse box and the headlight switch or between the headlight switch and the highbeam switch or between the high beam switch and the headlights...you just need to get a test light or voltmeter and figure out where...once you do some more trouble shooting where there's power and where there isn't power, you'll have a good idea of what you need to replace or fix

I did clean up all the wires under the dash to find that all the stock wires are in their correct location. Where does the 12v signal come from for the headlights?

[Stitch]

Originally Posted by Slofarmtruck

I did clean up all the wires under the dash to find that all the stock wires are in their correct location. Where does the 12v signal come from for the headlights?

I'm assuming from the fusebox...and there should be a fuse on them

[Slofarmtruck]

I stared at the fuse box forever and even checked all the slots for a change in voltage with the new headlight switch on/off. I saw no fuse labeled for the headlights and found none that were changed with the headlight switch.

[Stitch]

take the connector off the headlight switch and put a test light on each pin inside...one of them should have power constantly

[Slofarmtruck]

Originally Posted by Fat Hoe

take the connector off the headlight switch and put a test light on each pin inside...one of them should have power constantly

Thanks for all the help!

[Stitch]

if it doesn't have power, I can test my light switch and see which one should have power...that way you can run power to that one pin and see if the headlights work...my dash is apart right now so it would be the perfect time...lol

[Slofarmtruck]

I will let you know for sure if that is necessary! Thanks for the offer.

[Slofarmtruck]

Woohoo!! All fixed..well patched at least. Turns out the Hi/Low beam switch on top of the column was faulty. I jumpered the low beam side of the wire harness and now everything works again. I will replace that switch this weekend once I get the motivation to remove it. In a celebration I drove the truck to work today and other than a few abnormal bangs, clanks, and squeeks she made it with no issues. Thanks again for all the help.

[Stitch]

no problem...glad you got it back on the road...feels good huh?

[Slofarmtruck]

Feals great! I smiled the whole way to work and can't wait to drive home!