This saturday im getting a lawn tractor off my uncle and i gotta get it to my house, about 12 miles, so im renting a trailer from u-haul. My blazer already has everything i need except the ball, the thing im wondering about it the wireing harness on it (for the lights on the trailer). Its older and has a decent amount of rust in/on it, i got under it and i can eaisly get to the wiring on it. Is this something i need to worry about or do you guys think it will still work?

 

You probably should just replace the harness. If it is the flat 4 pin harness, it should not cost all that much. You definitely want the lights to work.

 

You should try testing it out first to see if it works...if it doesn't, replace it.

 

Most rental outlets are pretty helpful. They won't let you leave without it working. (liability) They will most likely clean the terminals when they hook you up if it doesn't work at no charge. If it needs replacing it will cost something though.

If you want to try it yourself:

You may need to clean the oxidation, (I'm assuming this is what you mean by rust), out of the plugs. The (white) ground wire is the most famous for failing, clean both ends especially at the frame.

Turn your lights on and a turn signal then test the output of each female terminal using a good ground source, then use the ground on your plug, (white) to be sure it will provide a good connection. You shoud get a steady or intermittent 12V from each terminal using both the alternate ground source, (frame) or the white wire. then try the other turn signal, a different plug will show intermittent power.

Yellow and green = turn signals
Brown = tail lights
I can't remember the brake lights but just turn off the lights and turn signal, have someone put on the brake, then test your outlets to make sure. If the brown one only lights up you are fine, that goes to both lights.

I have a variety of little wire brushes to clean the terminals out. UHAUL may have one in their store. Just be carefull not to widen the connector when you clean it as it will fit to loose on the trailer harness and either not work or flash. I have used needle nose pliers to gently squeeze them back together to ensure a tight connection.

You will need a cheap 12V tester I have sometimes used a 12V light bulb with a prewired pigtail or other 12V accessory. I have also seen a 4 pin plug in tester with built in lights made just for this. Again, UHAUL can do this for you, or just borrow it at the strore.

The fuses for trailer towing are in the power convenience center under the hood on the drivers side. Check them first.

Good luck

 

You can get a trailer connector circuit tester that plugs in. Testing with a multimeter may be iffy cause you may be able to get to a good point in the terminal and get voltage, but it may not work when plugged in due to the corrosion.

 

So when I go to u haul they can do this for me?

 

I would not wait until then to figure out that the connector is messed up...

 

Um, will advance auto have the tester? Sorry if im not up on my car care but im learning lol

 

Just a suggestion, stop at the rental firm to reserve the trailer, tell them you are concerned your wiring harness is working, ask if they could do a quick check to avoid problems when you pick it up. They will have a tester and the best advice.

Replacing the harness may not help and may be needless. Just because it is corroded is not reason to replace it unless it is shorted with brittle wires etc. The ground wire accounts for 90% of trailer wiring problems. Cleaning the ground is routine for anyone who tows regularly. You may have to do this with a new harness anyway at the frame connection.
I'm sure the rental company will be happy to plug in their tester to get your business. If not find another one. It doesn't sound like you will be towing again soon so why but a tester you won't use IMHO. This is what service businesses are about. I had a guy replace my fuse for towing after checking it and no charge.

 

Sounds good, ill let you guys know how it goes!