I need help with electrical problems , please

I have an issue with electrical work. I may have solved an issue with my headlight situation, but I do wanna purchase a oem/aftermarket head light harness so I can get rid of the corroded wires…
but any who,
!brake lights don’t come on when I turn on head lights! The whole back even third as well.
so, the fuses I checked under the dash and that I seen were blown when I tested it. It was “ Panel “ and “ tail “. So I removed them and replaced the “ blown fuses “ and when I went to go check again still nothing. then I thought probably not getting power or grounding somewhere… I checked the outer fuse box, those were all the hi/Lo, everything to deal with headlights. Like literally everything I replaced about 5-7 of them in the front and 2 inside.

yeah the headlights, I’m trying to find a oem harness or aftermarket to see if that fixes the headlight Situation. But get this my headlights still come on so idkk, but I still wanna change it out because the wires are fried.

then for the rears I’m lost of words, and that panel fuse as well, and recently my reverse camera stopped working as well ‍

any help will be greatly appreciated I’ve done electrical work. And now I wanna replace my harnesses I ruined because of careless decisions I thought was cool but bit me in the ass in the long run. So if y’all got any links for head light harnesses, just the harness and not whole engine harness for just head light harness, that’ll be greatly appreciated. Thank you

P.S.
I’m kinda up to the point where I was gonna replace the whole electrical system under the dash… but I do wanna fix my brake lights for sure, I can’t even drive my truck at night…

 

Welcome to the forum. Calling @caribe makaira and @crashnburn80 (they are the resident electrical experts around here).

 

hello, thank you for the welcoming , I’m already lost in the electrical work. To the point where I was gonna order new everything. But if I can find out the problem and I know theirs available parts for that problem at a cheaper cost instead of blowing it all on electrical things and come to find out a wire was grounding etc

 

Big word of caution... these trucks are very current specific. Lots of fried electronics and ECUs due to amateur hour in the driveway.

 

Is it the brake lights or tail lights? Or both?

 

What kind of modifications were you working on? Seems like there is a short somewhere that is blowing the fuses..

 

Yeahhh, it was one of them amateur hour kine things back then. And now it’s biting me in the ass lol.

 

It’s the tail lights, when you turn it on with the headlights rears do not turn on. Only when I step on brakes the brakes light up

 

I had modifications on until I took them al off since I repainted my truck. I just want everything back to stock and working properly

 

The tail lights are controlled by the Body ECU.
The Body ECU controls the Tail Relay.
The Tail Relay feeds power to the Tail fuse.

I’d start by checking the Tail Fuse for power. The Tail / Headlights need to be on when checking.

 

You get a cookie for an almost complete.

 

Why the repaint? We’re you in an accident? If so maybe that has something to do with it??

 

why repaint? Because I paint cars and I wanted to paint my truck for the Fck of it.

 

tail fuse has no power, with the ignition on and lights on. And my continuity doesn’t light up nor make a noise but when I check others to make sure my tool is working.. but thank you , I’ll try again tonight to figure out the problem…

 

I should’ve mentioned that I had a towing package as well but Thank you.

how would I read this diagram without getting too lost lol

 

You can start at the power source and work your way testing each of the pins pictured for voltage until you have no power, or you can do the opposite and work your way back from the tail lights checking to see where you have voltage.

Keep in mind relays need to be energized to latch. Plenty of YT vids explaining how relays work. I would caution that you need to know your way around a multimeter as you are probing so you are not shorting any circuits. In no way do I mean this as an insult, but if you have to ask how to read a wiring diagram, it may be best to involve a friend or hire a pro to help you solve this. Again, not trying to insult you in any way; just a word of caution before you start to probe around your Taco.

 

I think I had a similar problem once. I had to replace this fuse:

 

The chances you have a a bad relay are pretty slim, the chances you have 2 bad relays are even more slim.

I’m curious if the Towing Tail lights works. The one at the towing connector.

If you’re wondering why, it’s because both relays are controlled by the same TRLY connection at the ECU.
This isn’t the right why to definitively diagnose the issue, but it definitely gives you an idea of where you’re headed next.

Check the fuse for the towing tail first.

 

Just asking to see if maybe you were in an accident (repaint) and maybe you had an underlying problem from that.

 

That's awesome work! I would love to learn how to paint or wrap cars some day, and possibly even weld because both are expensive Lol.