SFR Chasing down trailer light problems (on the tow vehicle side)

Sorta fishing-related
Evan B said:
My expedition had this issue. Worked until it didn't. Tried troubleshooting but decided having Uhaul redo the entire wiring and plug for $60 was more worth my time.
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That can be a real headache saver and might be worth it if you continue to have issues. I spent the first 6 weeks I owned that MG chasing stuff, cleaning connections, and just getting the wiring correct. We had to do my son's first truck & boat trailer and it took about 3 hours to get everything done.. Clean grounds and renewing connections. Splits in wire casings can cause problems as well.
 
If it isn't a factory wiring installation, which I bet it isn't. Chances are the connections were done at the tail light assemblies. Easy way to check is to remove the tail light bezels and look. Depending on the stop and turn configuration, there maybe a diode block that was installed. As the stop and turns share the same trailer bulbs and circuitry, the diode block keeps one of the turn signals inadvertently sending current to the other turn signal. I suspect it is either a connection to the vehicle wiring, or a bad diode. You tube and a test light are your friends.
 
Evan B said:
My expedition had this issue. Worked until it didn't. Tried troubleshooting but decided having Uhaul redo the entire wiring and plug for $60 was more worth my time.
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My first step in trailer electric problems is go to the nearest Uhaul. But then the only thing I know about electricity is how to pay for it.
 
Most of the time I have had trailer light problems it has been the ground. As others have said, it can do weird things. Wire brush and dielectric grease are helpful.
 
I had a 1994 Ford Ranger that I towed a few different trailers with that had the same issue. The culprit was the ground.
I can't remember exactly what I did to rectify but I do remember plugging a new 4 flat harness into the the factory connector junction behind the gas tank on the frame (standard T plug in), and then ran the ground wire from there, to a seperate plug on the trailer...as in seperate from the trailers 4 flat female receiver.
It was some stupid Ford thing they did at that time that was very frustrating.

Wish I could be of more help but my trials were a long while back.
If I had to do it again a shop would likely be getting my $.
 
O' Clarkii Stomias said:
If it isn't a factory wiring installation, which I bet it isn't. Chances are the connections were done at the tail light assemblies. Easy way to check is to remove the tail light bezels and look. Depending on the stop and turn configuration, there maybe a diode block that was installed. As the stop and turns share the same trailer bulbs and circuitry, the diode block keeps one of the turn signals inadvertently sending current to the other turn signal. I suspect it is either a connection to the vehicle wiring, or a bad diode. You tube and a test light are your friends.
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I wondered if this was an aftermarket installation, if so, I think many of these are prone to failure (at least in my experience). Road deicing chems/salt wreaked havoc with my RV dealership installation (more than once on the same rig). Good luck @Josh - I turned to the local canopy shop/Uhaul dealership.
 
I had a do all mech. I just took my problems to him and they were fixed posthaste. Fixed on the spot. I have even fixed them a time of two. But not anymore. To god damn old to be crawling around under a vehicle of any kind.
 
Dustin Chromers said:
Are you solved yet Josh?
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No. Mostly because the weather has gotten rainy which has made me less interested in crawling under the truck.

Might just call uhall and see what they charge to deal with it. I'd like to at least check the ground wire myself first.
 
Josh said:
No. Mostly because the weather has gotten rainy which has made me less interested in crawling under the truck.

Might just call uhall and see what they charge to deal with it. I'd like to at least check the ground wire myself first.
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Run a second ground between the vehicle and trailer.
 
Josh said:
No. Mostly because the weather has gotten rainy which has made me less interested in crawling under the truck.

Might just call uhall and see what they charge to deal with it. I'd like to at least check the ground wire myself first.
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I would bring the truck to Uhaul and pay them to find and fix the problem. Life is short and time is precious.
 
My 99 Ford has fuses and relays for trailer brakes, running lights, turn signals etc individually. Would be the first place I would check.
 
I'd replace all the fuses for all things trailer related, even if they don't obviously look blown. When I bought my current truck and hooked it up to my boat I had similar problems. Looked at all the fuses and they all looked fine, but decided to replace them all anyway and it solved the issue. Fuses are funny like that.

You may have already done so, just a suggestion if you haven't.
 
I would rewire. Your time is valuable.
After that get a 4 flat plug with the lights. You can determine if it is vehicle or trailer with that.
Whenever it is the trailer and not the trailer ground(easy fix), I rewire the trailer.
Don't get me wrong, I can chase the problem down. It just is not worth it. Start over. Buy an extra kit for next time. Iclude zip ties, shring tube connections, and a wire stripper in the kit. No trailer leaves home without that kit.
Cds
 
X2....been to that dance way too many times. These days I just pull off the old lights and wiring, install a new set of LED's and fresh wiring to the receiver, $75 and a couple of hours, done.
 
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