Electric problems following trailer hookup

2006 Tacoma TRD Off-Road

Yesterday I purchased a 1996 trailer and plugged it into my trailer brake (already there when I purchased truck) and when I turned the truck back on I could not get it out of park. I used the manual override to get it out of park and drive home. But the check engine light was on, the airbag light was on, the A/C did not work, and my signals would not work. Of note, the left hand signal on the trailer did not work also. After disconnecting the truck from the trailer, the problems continued and still have to use manual override to get out of park. I couldn’t find any blown fuses, what could it be, and what should I do? Thanks all!

 

Check your IG1, ACC, and STOP fuses.

 

Did not realize there was a fuse box in the cab! Found the IG1. It was indeed blown. Hopefully that fixes the problem. What should I do to prevent this from happening again when I want tow the trailer?

 

Need to figure out what is shorted/mis-wired on the trailer.

If you have the factory tow package the only thing the IG1 Fuse powers at the trailer plug is the reverse light circuit which most trailers don't have so something is likely tied in there that shouldn't be if the trailer doesn't have backup lights.

 

Testing the truck side of the connection might be a good place to start. Does a test light show all the pins working properly?

Some aftermarket harnesses / converters have caused some unusual problems when an electrical load was added.

 

Replaced the IG1 fuse. All the electrical problems fixed but the check engine light is still on…

 

You will need to clear the codes or wait a few drive cycles for them to clear.