Weird brake and blinker lighting problem

[Bigpeekay41]

I searched for this problem but there was nothing exactly to this.

I have a 97 LTD 4runner. When ever I press the brakes the left blinker light on the dash lights up and the blinker on the truck lights up solid. When I press the brake and put on the left blinker it blinks normally. I don't understand how my left blinker lights up solid on the front and back when I press the brake pedal.

Any help on how to solve this would be great! thanks guys

 

[Elton H]

maybe theres something wrong with your trailer harness ?

 

[wiretie44]

maybe theres something wrong with your trailer harness ?

:iagree:

 

[Ron Helmuth]

could be several things

I've read elsewhere this could be as simple as a dual filament bulb grounding itself out.

But the symptom you describe could also be the trailer converter wiring box acting up as Elton and wiretie point out. It's a common little black box failure that is hidden in the rear cargo area corner behind the trim work. For your year I can not quickly recall if it is on the drivers side or passenger side rear corner.

So first question would be- do you have the towing 4 pin connector out back? If so one of those LED tester lights is a handy thing to have.

But first I would just remove a taillight bulb one at a time and see if that eliminates the issue...narrow it down if you see what I mean...

I'm a bit confused by the part about "blinker on the truck lights up solid". I take that to mean your dash lights inside the truck illuminate when you hit the brakes and that is exactly what was happening to me when the brake signal was accidently wired up to the parking light wiring.

Fairly common problem -do not let it get you down. We'll help you to narrow it down and search "trailer converter 4Runner" here or Google or Yota Tech.

 

[Bigpeekay41]

Thanks so much! Yeah when I press the brake the right blinker on the dash and on the truck lights up solid. I will most likely have more questions I will get back to you ASAP

 

[Bigpeekay41]

So first question would be- do you have the towing 4 pin connector out back? If so one of those LED tester lights is a handy thing to have.

What exactly would this show me? I'm a bit confused, with my lack of knowledge on wiring.

And yes my truck does have a 4 pin connector in the back. I know most auto stores will let you borrow the check engine light testers, is this similar or the same thing?

 

[Ron Helmuth]

the 4 pin LED tester plug in will snap into your existing wiring at the hitch and confirm that the symptoms you are describing are exiting the vehicle at the trailer converter.

Would be easier to confirm that it's not just the bulb first. Remove one taillight-pick either side and remove the stop light and parking light bulb one at a time-it's my guess they are the same bulb. Then see if it still happens. Easiest to see this in a dark garage or when it is night out.

No this tester is not related to the diagnostic 'engine light' tester.

Check the bulbs first. Do one side and when you remove it look closely at it. A dual filament bulb has two actual assemblies within the bulb-one for the stop function and one for the parking light function. If we're lucky one of those is simply blown and laying against the other filament. Once the defective bulb is removed the symptoms should go away meaning the truck will show normal brake lights when you step on the brake and not light up the parking lights and dash lights.

really helpful to have an assistant to watch your tails or your fronts while you press the brake or they press the brake and you watch the lights.

 

[Bigpeekay41]

Awesome! I will see if that is the problem tonight. Thanks Ron!

 

[Bigpeekay41]

Check the bulbs first. Do one side and when you remove it look closely at it. A dual filament bulb has two actual assemblies within the bulb-one for the stop function and one for the parking light function. If we're lucky one of those is simply blown and laying against the other filament. Once the defective bulb is removed the symptoms should go away meaning the truck will show normal brake lights when you step on the brake and not light up the parking lights and dash lights.

Question, when I press the brake pedal the left front blink lights up solid on the truck and the left back blinker lights up solid on the truck and the left blinker on the dash lights up.

I don't understand how it could be the bulbs if pressing the brake pedal lights up the front left blinker? The brake pedal and the left front blinker have nothing in common with bulbs. or does it?

I'll check the bulbs, but i don't get how pressing the brake pedal lights up the front left blinker

 

[Ron Helmuth]

logically that does not make sense to me either

yah I would agree it's likely the trailer converter box-but just suggesting you check bulbs first as it is easier than tearing into the back end trim.

Here is a shot of the replacement black box from Hopkins via Amazon-I can now direct import photos in now which I just became aware of late last evening

 

[Bigpeekay41]

yah I would agree it's likely the trailer converter box-but just suggesting you check bulbs first as it is easier than tearing into the back end trim.

Here is a shot of the replacement black box from Hopkins via Amazon-I can now direct import photos in now which I just became aware of late last evening

Ok next solution, once I tear into it, what am I looking for to fix?

 

[Ron Helmuth]

so you verified the bulbs are okay?

The bulbs checked out okay? You swapped one side to the other and still have the same issue?

Hook up the LED tester to the 4 pin and see what functions are not working. Search Trailer Converter or Taillight converter here or Yota Tech or Google.


If you are sure it is the black box itself then order a new one and swap it in. I was able to figure it out and chronicled the wire up both here and on Yota Tech. It took a bit of doing but as long as you keep track of which wire is what (the color coding is matched by Hopkins to make it as simple as possible) then anyone can figure it out.

Like a lot of my projects my able assistant-the 17 year old son- was the brains of the outfit and kept me on track.

You can splice in or buy a fully plug and play unit that connects to existing plugs at one side and runs to other side to exit out to the 4 pin connector.

Please get other opinions and don't tear up all your interior trim just based on my long distance diagnosis. I'm simply reading your symptoms and making suggestions on what I guess to be the issue. Others may tell you I am just full of crap and don't listen to that guy....

I am no mechanic and not pretending to be...

Take a close look at my hitch area in this photo. Note my 4 pin LED connector hanging down from the top of the hitch. I highly recommend a splice in of the Hopkins LED 4pin-then if you ever have an issue like this again you have a built in diagnosis tool. It's about $8 more than the standard 4 pin connector and well worth it.

Alternately Harbor Freight sells an LED tester tool for about $6 or so. In theory you could just leave that tool plugged in all the time but some fool would just steal it....

Talk things out with the helpful staff at a Checker or other auto parts store and they will help get you straightened out as well. Nothing like some local guys getting involved.

lastly it is cumbersome to keep track of the threads I am involved in-since there is no email notification from the forum that you are speaking back to me. So here is my real email : [email protected] and feel free to talk to me more directly that way. If you see my previous posts you will get the gist of what is ahead of you.

But start at the beginning and let's make sure it's not simply a bulb issue. Modify your signature or Screen Name so if someone is right down the street from you they can jump in and offer to help. WA is a bit vague if you see my point...

 

[Bigpeekay41]

I did some more research and had a guy take a look and he said it looks like there has been some custom wiring done, everything is wrapped with electrical tape. I read through some books and figured out the wiring colors. Based on what I see and what others see, there is probably a left blinker wire touching a bare brake wire and is causing the simultaneous brake and blinker lights to pop up when I press the brake pedal. So its going to be a lot of finger work.

On the bright side, my back left chrome piece needs replaced so it will be two projects in one. (Trailer converter box on a 97 is driver side)

 

[Ron Helmuth]

thanks for the update

Glad you got some expert assistance to look it over.

And I have that chrome side bumper piece listed on Classifieds-however it does have a dent. Stay in touch if I can help further.