No Power To Brake Lights (1 Viewer)

FishTown

Proverbs 27:17
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Been a long while since I’ve posted on here. I’m working on an issue with @swingoftheaxe ’s FJ62 that we picked up a couple months ago.

I’ll start at the beginning - a couple weeks ago, his brake lights were not turning off. I met up with him and started thumping around at the brake light switch thinking it had gone bad. I was able to get his brake lights to turn off with some wire jiggling. However, now they won’t come back on. We didn’t research the issue first and just immediately bought a new brake light switch. After doing some reading it looks like it may have just been a pedal position issue. I’ve tested his old and his new used switch on my cruiser and they both function properly. But we’re not getting power at the brake light socket. We are getting power to the brake light switch itself. The PO installed wiring for a trailer - he doesn’t need this anytime soon so I’m going to sort of reverse engineer it back to stock to eliminate that as an issue. I’m NOT an electrical guy. I hate dealing with it and don’t have a great understanding of how it works, but I know I have to work my way upstream to see where the loss of power is. If anyone has any suggestions, I’d greatly appreciate it. Starting to dismantle trailer lights right now.

I should also mention that running tail lights and reverse lights are working.


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What I see Crimp locks. Remove that crimp lock and fix the original wires. Crimp locks are nothing but lazy wiring and always lead to problems. That might not be your end problem but it’s not helping. And for future wiring I have a thread on a plug and play harness and there are some other threads that are similar that detail which harness and what has to be done to it to make it work.

have you checked to make sure you didn’t blow the fuse?
 

FishTown

Proverbs 27:17
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What I see Crimp locks. Remove that crimp lock and fix the original wires. Crimp locks are nothing but lazy wiring and always lead to problems. That might not be your end problem but it’s not helping. And for future wiring I have a thread on a plug and play harness and there are some other threads that are similar that detail which harness and what has to be done to it to make it work.

have you checked to make sure you didn’t blow the fuse?

Yeah, planning on taking those out with rest of the trailer harness. I did check there and not getting power on the upstream side either. And yes, fuse is good and getting power there.

Trying to get this main connector unplugged but, man, is it a b*tch!

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Yeah, planning on taking those out with rest of the trailer harness. I did check there and not getting power on the upstream side either. And yes, fuse is good and getting power there.

Trying to get this main connector unplugged but, man, is it a b*tch!

View attachment 2441187
Spraying a little wd40 on the connector sometimes helps free them up. Just wipe it down good afterwards. Get the dust and drift out. Maybe hit it with some circuit board cleaner and then apply a light film of dielectric grease on the pins (FYI my phone tried to auto correct dielectric to “diesel truck” ....not the grease I’d recommend 😂)
 

FishTown

Proverbs 27:17
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Well, no power at that plug. So we decided to remove the dash to get a better look at what’s going on. Turns out the PO did some hacking on the harness, unfortunately. Clipped wires right at the original connectors. Need to look closer at the connector to see if we can attach new wires and make sure that’s where the power stream ends.

The PO also put a bunch of led lighting around the truck and tied in some relays for the turn signals. It’s a bit of a mess so the plan now is to return as much of it to stock as possible.

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Ouch,
Sounds like you have a lot of work ahead of you sorting through that wire hack job.

I usually say check out the rear driver's quarter panel for corrosion but you're already in there and that looks rough.
 

FishTown

Proverbs 27:17
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Ouch,
Sounds like you have a lot of work ahead of you sorting through that wire hack job.

I usually say check out the rear driver's quarter panel for corrosion but you're already in there and that looks rough.

The truck had spent all of its life in the desert, so there’s almost no corrosion anywhere. Remarkably clean in the panels.
 

morganism

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On mine, the rubber flaps over rear vents rotted, water dripped down on side marker plugs, and burned wire right at the harness connector of 20 up there at dash.

And it's a desert rig too.

PO just ran a new wire back to runn light splitter in rear.
 

FishTown

Proverbs 27:17
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We found the culprit. A crimp connector under the dash cut through the brake light wire. Got all of the that crap out and the brake light wire properly spliced. Now we’re back to the original issue - the brake lights are staying on and won’t turn off. I have the brake light switch adjusted all the way forward, but I guess it’s still not getting pressed all the way by the pedal. I even tried pulling the brake pedal back further but it still stays on. His brake booster is also starting to go out (that’s the next job) - would it be that the pushrod needs to be adjusted?
 
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So if you just have the brake light switch in your hand with the wires attached do the lights switch on and off with movement of the switch? If so it sounds like maybe you have the wrong rod or booster or something got damaged in the pedal mount.
 

FishTown

Proverbs 27:17
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So if you just have the brake light switch in your hand with the wires attached do the lights switch on and off with movement of the switch? If so it sounds like maybe you have the wrong rod or booster or something got damaged in the pedal mount.

Yes, it functions properly when just hanging down. Brake booster is the original (or at least an OEM unit) and has been unaltered since he’s had it. It looks like the pedal is pressing the switch all the way in, but it’s kind of hard to see down there.
 

FishTown

Proverbs 27:17
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This one...which you posted in ;) Brake Switch Bumper?

Ah. I thought you were referring to something other than that. I kept looking for the word spacer. Yeah, we’ve already ordered a new one. I guess we’ll see if that fixes the issue.

Here’s a couple more from the other night. We were up til 1 am sorting out and removing wiring from the PO and repairing the wiring harness.

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Nothing worse than a truck that a previous owner tried to improve using less than proper skills. I've seen headlights wired with speaker wire, crimp locks, random alarm components, strange brackets, wrong bolts, zip ties used in applications that shouldn't use zip ties, black duct tape, the list is endless.
 

FishTown

Proverbs 27:17
Joined
Jul 19, 2010
Messages
1,349
Location
San Antonio, TX
Nothing worse than a truck that a previous owner tried to improve using less than proper skills. I've seen headlights wired with speaker wire, crimp locks, random alarm components, strange brackets, wrong bolts, zip ties used in applications that shouldn't use zip ties, black duct tape, the list is endless.

Lots and lots of crimp locks (one of them cut through the brake light wiring). Residential wiring ran underneath and zip tied to brake lines. And all for cheap accessories. But it’s all out now.
 

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