Ok, I have a 97 F150. When I bought my car trailer, I went to Walmart and bought an adapter to go from the truck to the trailer, which has the smaller round end. The adapter didn't work though. I know the brakes didn't work and maybe only the running lights would work. No signals, brakes lights. I brought the connector back and got a different one. I don't remember if it was a different part number but I believe it was.

My question is, is there a difference in the different plug between say Ford and GM? Whenever I tow trailers for friends for say a bobcat or dump trailer, it seems I'm always having a problem with signals and brake lights not working. They all have Chevy trucks. Is it just a matter of the pins in a different configuration or what? I do not want to haul stuff for people anymore without brakes or lights working properly, no matter how far I go. I don't want to spend the time pulling the plugs apart and diagnosing it if it's a matter of just needing to get a different plug to keep on hand.

Thanks for any help you can give.

Paul

 

Not sure if this is going to help, I have an 05 and was replacing bulbs on my trailer with the harness still attached to the truck, found out the hard way that is a NO-NO. Anyhow I ended up blowing two fuses in the main fuse box. This directly affected turn and brake lights on the trailer. Once these fuses were replaced everything light wise on the trailer was working.

 

Check the engine mini fuse panel ( page 142 of your owners manual ) for the stop / turn fuse. This is just for the trailer tow adapter ( 4 pin or 7 pin ), could be blown.

If this is OK, you can check the left and right trailer tow adapter stop/turn relays. This is in the aux relay box, next to the battery junction box ( aka engine compartment fuse panel ).

Here is the layout of it.


The trailer tow adapters should be wired the same, but lord knows what someone did with their trailers. I have seen people do strange stuff with their adapters, and when it is time for another vehicle to tow the trailer, nothing works correct, they blame it on the "Ford", forgetting that they changed things around trying to make it work years ago.

If you are going from 7 pin round ( the large round plug, or RV plug as it was called years ago ) to a 6 pin round, it should be good to go with an adapter by Hoppy or the likes, again if the owners did not jack up the trailer wiring trying to make it work.

This is a 7 pin to 6 pin & 4 pin adpater

This is a 7 pin to 6 adapter.


Both of these are from etrailer.com

Best to check what is going on with the 7 pin to 6 pin adapter you have, and make sure the 6 pin on the trailer is wired correctly.

 

I have a 01 with towing package. All my lights work with the exception of the brake lights. All the fuses have been changed, the brake on/off switch has also been replaced, and the blubs have been changed and still nothing. Help please.

 

When you say all fuses, which fuses are you talking about ?

The 2001 trailer tow adapter fuses for the stop/turn are in the BJB ( aka Battery Junction Box, Engine Compartment fuse panel ) fuse #19 & 20.

Have you checked the truck's stop/turn lamps ?

If the truck's stop / turn lamps worked, replacing the BPP ( brake pedal position ) switch was a waste of money.

 

I replaced the lamps and still no brake lights. Like I mentioned earlier all the tail nsection lights work except the brake lights. I think I might have a short in the trailer wiring. How would I go about checking that?

 

Replaced the bulbs on what ? ( trailer or truck ).

Do the stop / turn lamps work on the truck ?

If the truck's stop/turn lamps work correctly, did you check BJB fuses # 19 & 20.

Not real sure if the only problem is on the trailer, and if the problem is only on the trailer, you are replacing items for no reason. Bit of focus with the diagnoses would help a lot here.

 

I have the same problem, my trailer brake lights don't work. All other lights on the trailer work. I checked all fuses including BJB fuses 19 & 20 all ok. Please help.

 

When you tested BJB fuse 19 & 20 was power not on either side ?