When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well, the wifes been driving my '90 4Runner, and told me that someone stopped her to tell her that her brake lights weren't working. They were right.
My first suspects were fuse and brake light switch. Well, the fuse is good and there's 12V coming in and out. So, I get flexible and pull the brake light switch. It tests fine.
So, now I check the brake light switch plug. Uh-oh, no power there. That's my problem. Unfortunately, I don't have a wiring service manual, and can't exactly tell how the wire gets from the fuse panel to the brake light switch plug.
I could definitely rig up a 12V wire to the plug to get the lights working, but hate to butcher my pristine rig. Anyone have a schematic I could reference, or know where one is located on the 'net?
The brake light system on your truck is very simple. Power goes from the brake fuse to the brake switch to the brake bulbs (which are wired in parallel) to ground.
So, if you have power coming out of the brake fuse (are you sure you checked the correct one?), and no power coming in at the brake switch, then you have a broken wire (or connection) between the fuse and the switch. The wiring diagram for my '93 4Runner shows a green with red stripe wire coming to the switch from the fuse, and a green with white stripe wire going from the switch to the brake bulbs.
Do you have trailer wiring? I once saw a trailer harness come apart and cause the rear lights to not work. It was not on a Toyota, but it might be something to check.
try this: take your fuse and bend both prongs slightly in opposite directions and then put the fuse back in. what happens over time is the fuse doesnt sit in there as tight as it used to and will slip out. when you test the fuse you are putting pressure on it making it contact. This is what happened to me on my 92. Drove me nuts, till the gf's dad came in to the garage, bent the fuse prongs, and then laughed at us.
I forgot about corroded fuses. That exact thing just happened in my Blazer. My tail lights were not working and it turned out that the fuse got corroded. I scraped the blades off and the lights started working again.
For the life of me, I can't find the one that shows the brake light wiring diagram. Is it just me? Good reference pages, though!
Originally Posted by GSGALLANT
The brake light system on your truck is very simple. Power goes from the brake fuse to the brake switch to the brake bulbs (which are wired in parallel) to ground.
So, if you have power coming out of the brake fuse (are you sure you checked the correct one?), and no power coming in at the brake switch, then you have a broken wire (or connection) between the fuse and the switch. The wiring diagram for my '93 4Runner shows a green with red stripe wire coming to the switch from the fuse, and a green with white stripe wire going from the switch to the brake bulbs.
Yes, the Green/Red wire from fuse to brake light plug appears to be the one I'm having issues with, thanks. I wonder if the wire goes straight from the fuse-panel to the plug, or what? And what's the best way to access it? Pulling the fender?
Originally Posted by the_supernerd
Do you have trailer wiring? I once saw a trailer harness come apart and cause the rear lights to not work. It was not on a Toyota, but it might be something to check.
I thought about this, and do have factory towing package with module under drivers side tailight. But, since I don't even have power at the brake light switch, the problem has to be before the trailer light module.
Originally Posted by Godzilla
try this: take your fuse and bend both prongs slightly in opposite directions and then put the fuse back in. what happens over time is the fuse doesnt sit in there as tight as it used to and will slip out. when you test the fuse you are putting pressure on it making it contact. This is what happened to me on my 92. Drove me nuts, till the gf's dad came in to the garage, bent the fuse prongs, and then laughed at us.
I will try this. can't hurt, right?
Thanks everyone for the suggestions. I'll let you know what I find out when I get home from work. That is, unless someone rear-ends the wife. She could use a good rear-ending anyway.
try this: take your fuse and bend both prongs slightly in opposite directions and then put the fuse back in. what happens over time is the fuse doesnt sit in there as tight as it used to and will slip out. when you test the fuse you are putting pressure on it making it contact. This is what happened to me on my 92. Drove me nuts, till the gf's dad came in to the garage, bent the fuse prongs, and then laughed at us.
Godzilla, you're the MAN! I was about to rip my dash and front end apart to find that loose wire, but figured "what the hell, I'll spread the stupid fuse".
Godzilla, you're the MAN! I was about to rip my dash and front end apart to find that loose wire, but figured "what the hell, I'll spread the stupid fuse".
Bingo!
Thanks again.
hahaha, right on, im glad it worked. I went through the same pain until something as simple as bending the prongs worked.
Well its a pretty old thread, but man do I feel like an idiot!!! I have been trying to fix this same problem for a month now and I just got my new brake light switch in the mail today. Of course the new switch did nothing to fix my lights so I decided to search around on the site for an hour and found this thread.
Who would have thought that bending the fuse prongs would fix the dang brake lights. I tested the fuse multiple times and replaced it with a new one twice. I just cant believe I've been stressed about this for a month, if i would have searched a bit harder the first time I would have had the problem fixed in 30 seconds.
Thanks Godzilla, you saved me another weekend of stressing and driving without brake lights. I am going to start bending my fuse prongs first anytime I lose power to something.
Do you have trailer wiring? I once saw a trailer harness come apart and cause the rear lights to not work. It was not on a Toyota, but it might be something to check.
i had this happen to me, i just bought a truck and thought i had a nightmare about to happen, you hit the brakes the headlights come on, hit the blinker brake came on, turned the flashers on, well they worked but everything else was retarded. ended up being the trailer switch had drug the ground and all the contacts were touchin each other, i pulld the trailer portion out, and it fixed the problem.
kinda weird about the fuse though, havnt ever heard that one.
You can't add me to the list of people thankful for this thread! Was wondering why my brake lights weren't working, went and got more bulbs and fuses, then saw this. Solved the problem right away.
Totally newbie here so hey all. I just brought home my first 4runner tonight. A green 94 in pretty good shape.....get home and the brake lights aren't working. Everything else works fine so I'm going to try the fuse trick and report back tomorrow.
Looking forward to a lot of learning.
Okay so I have a weird situation. I welded my own bed for my Toyota and I needed to put some lights on it, so I ran down to Tractor supply and bought some. Last week I had it wired and everything worked fine, then there was a faulty connection coming off my starter relay the wouldn't let the truck start. I fixed that after taking the whole interior apart and now the running light work but the brake lights don't, if I switch the two wires where they plug into the harness then the brakes work and the running lights don't. Any ideas?
Well, I'm an idiot. Somebody pulled up next to my while driving and told me both brake lights were out. OK, fine, and "thanks buddy!". I bought 2 new bulbs and a switch (got the switch just so I wouldn't have to go back to the auto store again). I looked at the existing light bulbs and they both looked fine. Plus, the tailights worked (the rear red lights that come on when you turn on the headlights). So I went to the fuse and it too was fine. Then I went to the brake light switch, took out the old one and installed the new one. Still no brake lights! ˟˟˟˟! So I researched some more and people were talking about checking the wiring. I made a note to myself to grab my wire tester out of storage (tomorrow) to do some testing. Then, just for ˟˟˟˟s and giggles I went back to the bulbs, took out the old ones, put in the new ones and WALLA! LIGHTS! Like I said, I'm an idiot. Here's the TWO lessons I learned: 1.) Just because the bulbs look fine, AND just because your tailights work but the brakes don't, doesn't mean the bulbs are OK; 2.) START with the simplest solution(s) first!!!
Well I scoured Toyota Nation for any help in a no brake light, no dash lights and all gauges NOT!! working, nor a/c ..heater blower motor working scenario, and never found anything that worked!!... I had alot of electrical malfunctions that started slowly one by one and avalanched into total failure on my 91 yota PU....And Im a very savy mechanic!!...been spinning wrenches for 50 outta my 60 years on this planet, and have acquired ALOT of old school tricks along the way that Ive passed on to my younger aspiring wrenches!!....But again it proves that the old saying is still as true as ever!!....Lifes a constant learning curve and when it comes to mechanics and troubleshooting, ya cant know EVERYTHING!!....It completely escaped my mindset to suspect my fuse panel going bad!!...seeing how I had good voltage from the connectors and its condition looked pristine!!....here I stumble across Godzillas suggestion on this forum, to clean the tabs on the fuse and then bend them a little in opposite directions, and WHOLLA!!....Everything is working again, with now enough pressure to the tabs for now to secure the fuses in a current flow situation once AGAIN!!....Yes Im gonna replace the entire fuse box with a brand new one If I can find one!!....but just wanted to say TY YotaTech forum for not deleting this old thread and many thanks to Godzillas contribution in helping out this Old dog learn a new trick!!....The old 91 lives to roll on the road again!!
02-09-2016, 10:29 AM
Was wondering why my brake lights weren't working, went and got more bulbs and fuses, then saw this. Solved the problem right away.
Useful Old threads never grow useless
