Huntn

A relative borrowed my 1998 S-10 to do a U-Haul tow. It's the off-road version. Sometime after I got it back I noticed that both the left tail light and the left white tag light are no longer working. So I really don't know if the trailer hook up is related to this problem or not.

I took the tail lights out and notice that both of the light bulbs for the tail lights have harnesses ( a couple of wires that come off the base of the tail light bulb) added for a trailer hookup. The wires are protected and not shorting out. This appears to be the only alteration to the wiring for the trailer. The original wiring for the tail lights as far as I can tell has not been tampered with.

I verified that both of the light bulbs in question are functional by swapping them to the right side. Everything on the right works but the left side is not illuminating as described above.

I've also checked several fuses and can't find any that are blown. I've looked at the fuses that might seem related like RRLGT, LRLGT, BKLGT, etc but they are not blown. Anyone know what fuse covers these two lights? (tail light + tag light)

So whatever it is, is effecting both the left rear tail light and left white tag light. Brakes lights work ok.

Any leads would be appreciated. Thanks!
-Dave

jdonline

Do you think it's possible that the taillights weren't working prior to you letting your relative borrow your S-10 and you just didn't notice it till afterwards?Did they tell youanything theymay have done that might have altered your taillights' performance?

JD

golfer

I'm a little confused here ... there are wires attached to the bases of the bulbs for the trailer hookup ... is this something you did ?? Why didn't you get an adapter harness to plug into the vehicles harness ?
It sounds like the issue is with the spliced in wiring.

Huntn

It's very possible that this issue existed before the trailer hookup. I'm mentioning it because it could be a factor in the problem. Thanks for responding!

Huntn

The bulbs in the tail light sockets are special bulbs made for trailer hookups. I believe they used a U-Haul trailer and the U-Haul people supplied these bulbs If you look at the bulb, at its base are 4 wires that come off of it and dangle down into a connector. These two connectors, one off of each taillight hang down inside the fender just like the wire bundle for the tail light. The trailer electrical wiring plugs into these so the trailer taillights light up (head lights on) and the trailer brake lights function. This is the only alteration I'm aware of made to the truck when the trailer was pulled. If regular bulbs are put into these sockets there would be no alterations to the trucks electrical system that I am aware of. It may have nothing to do with the problem I'm having, but I mention it in case it is a factor.

I have swapped these special bulbs and the tag light bulbs. Whatever the problem it is just effecting the left side (left tail light and left tag light are both out).

I also notice 3 electrical connectors in the the back underside of the truck, one large one in the middle and two small ones on each side. I opened them and they have these metal teeth that look like they might function like fuses. They all look normal. Are they fuses or just connectors and do they control the tail lights? Could they be related to the problem I wonder. I need to look at them again, testing my lights with those connectors unhooked. Sound good?

It seems to me there is a bad connection somewhere, but the question is where? I really don't want to start pulling wiring out of the plastic covers back there unless I have too.

Any ideas? Thanks!

norwalkfisherman

Get a test light and see if you have juice to the sockets, if you don't have juice, either a fuse is blown, or one of the connections for the trailer harness is corroded and needs to be re-spliced. If you need to resplice the wire, start with the first connection that was made for the trailer harness, that is probably the bad one.