Tail light problem

Hello everyone,

I tried searching the forums, and while I found similar issues, I couldn't find this exact problem.

I have a 2001 Tacoma. Both tail lights work until I step on the brake, then the passenger side gets no tail light or brake light, and the drivers side gets both brake light and tail light. When the tail lights are off, both brake lights work fine.

I looked under the truck and found the ground wire coming from the drivers side tail light, and it is not hooked up to anything under the tail light cover. There is also a red wire and yellow wire that are cut. They had electrical tape on their ends. I took a picture for you, the ground being the dark wire with the blue heat wrap on it.

Could the broken ground wire on the driver side be my problem on the passenger side? I have a multimeter and read 12v out of each socket if that helps. I'm sorry, I'm not very knowledgeable in this area.

Thank you very much,
Jake

 

I think I'm trying to figure out where the broken ground wire on the driver's side tail light should go. It is grounded to the chassis under the bed, and the wire that goes into the tail light assembly is exposed and not hooked into anything. Does anybody know where that end is supposed to be and if that could be my problem? I'm still unsure about the other two exposed wires in the tail light assembly.

Thank you again,
Jake

 

clean the 6 terminals on the taillight real well. I used CRC electrical cleaner with sand paper folded up. Then a little dielectric grease. That fixed my problem with very similar symptoms. My flasher would also flash fast....

 

Does it have a trailer light box plugged inbetween the harness and tail light?

 

Swdockter, thank you, I will try that.

mechanicjon, there is a trailer light box. There is one wire from that hooked up, the directional for the passenger side. The ground, driver side directional and one other wire (reverse maybe?) are all disconnected. I wanted to disconnect the one wire left but do not know how to take it out of the plastic housing(npt sure of the correct term?) it is connected into.

 

Maybe I can help a little here, I just wired in a trailer light hook up and had to figure out my '02 regular cab wiring.
I pulled the plug out of the left light and, drew the plug on a paper and used a test light to figure out what each connection does. I had to also look at where each wire went on the tail light unit.
Some of the plug terminals have multiple wires coming out that continue over to the right hand light and need to make a connection their in order to get a proper reading, so leave the right hand light plugged in when you test it.

It looks like those two wires don't cross over like they should to the right hand light, this theory backs up the situation you described. They may have been connected to the trailer lights at one time or connected poorly. That red wire on mine was my brake light I believe, I can't remember what yellow/black was.

What kind of trailer hook up is it? Flat four? If your lights are like mine I had to get a special converter box because we have separate brake and blinker lights. If someone wired things in there without the converter for a flat four connection, you may need to reassemble the system correctly.

 

floydvoid,

Thank you for the response. I believe you may be onto something as when I initially opened up the tail light on the driver side there was one of the trailer wires taped together with either the red or yellow wires. Maybe the trailer ground I disconnected I could put back on and try to figure out where the trailer lights hook back into there. Do you happen to know where each wire hooks up? I'm not sure if it is a "flat four" connection or not. There is 3 plugs on the connection, one for each directional and one for the brake. Another little plug for the ground it says. Any help is greatly appreciated.

Jake

 

Mines was doing this among other issues such as a turning signal light staying solid on and being unable to use it. Even had a case where using the hazard lights made both turning signal lights stay solid on. The problem was fixed by cutting the wires from the trailer fuse box. The fuse box (mines was a uhaul model) had gotten too old and compromised over time. Now it's been quite a while and I haven't had any issues at all.

 

Thank you crazytacoman, I should probably just do this since I don't use the box anyway. I guess I'm just confused because there is broken wires on that drivers side and I thought maybe they should be put back together or atleast that ground actually grounded, but I don't know crap about electricity.

Jake

 

It sounds like you have the four wire trailer connection. You really need to "key out" what each wire does in your left hand brake light by using your meter or a test light before you start connecting wires. If you make a powered wire connection to a ground you could have some flames when you turn on a blinker or hit the brakes.

If you uncase the group of wires going from your left taillight to the right one, with the trailer hook up in between you might find the other missing connection.

No wires should just be left naked and open like you show in the picture.

 

Thank you floydvoid. I have wire nuts over all the open wires right now until I get around to messing around with it later today. I think I'm gonna start by getting the trailer wires outta the picture and then try cleaning up the rest of the wires by attempting to see what they do like you said. Good idea seeing what is going on in the casing between the two lights, thank you.

Jake

 

Uh, "dielectric grease?" That's an insulator. I wouldn't put that anywhere near an electrical connection.

 

I use it on all my electrical connections. I am aware that it insulates which is helpful with those 6 open connectors. What I look for is to minimize oxidation of the connectors. The connectors are making physical contact with one another....dielectric grease is not going to stop the connectivity with said connection.

 

I’ll post a picture soon of how the wires ended up looking

 

It's 4 wires connected on the driver's side tail-light