7-Pin trailer wiring: Flash or No-Flash
01-31-2017, 11:38 AM
#1
JK Newbie
Thread Starter
7-Pin trailer wiring: Flash or No-Flash
Purchased the Mopar 7-pin trailer wiring harness for my JK. In many of the threads here there are differences in opinion whether the TIPM needs to be flashed (or Star Scanned) in order for the harness to work. I installed the harness but after about an hour the running lights went out and now I can not get them to come back on. Brake lights and turn signals work fine, just the running lights don't work. I tried on a friends trailer and he on mine and the problem is with my Jeep. I did confirm that the pin for the running lights is not getting any power. I contacted the seller and they looked up my VIN and said yes I did need to go in because my Jeep is set up for the 4 wire trailer wiring not the 7. Called local Jeep Dealer to bring it down and they said nothing is necessary and it should be plug and play. I'm stating to get really frustrated. The fact part of it works and part of it doesn't is the frustrating. Any suggestions?
01-31-2017, 07:33 PM
#2
JK Freak
Did a 7 pin on our 2012 Jeep with no issues. It was not the Mopar one and was install by uHaul. Still works like it should.
Purchased the Mopar 7-pin trailer wiring harness for my JK. In many of the threads here there are differences in opinion whether the TIPM needs to be flashed (or Star Scanned) in order for the harness to work. I installed the harness but after about an hour the running lights went out and now I can not get them to come back on. Brake lights and turn signals work fine, just the running lights don't work. I tried on a friends trailer and he on mine and the problem is with my Jeep. I did confirm that the pin for the running lights is not getting any power. I contacted the seller and they looked up my VIN and said yes I did need to go in because my Jeep is set up for the 4 wire trailer wiring not the 7. Called local Jeep Dealer to bring it down and they said nothing is necessary and it should be plug and play. I'm stating to get really frustrated. The fact part of it works and part of it doesn't is the frustrating. Any suggestions?
02-04-2017, 02:29 PM
#3
JK Freak
Join Date: Jul 2010
Location: Cadiz, KY
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I would check to make sure the running lights work on the jeep. If they do, then check the wiring from rear lights to the plug. If they don't, then I would check the wiring to the rear or fuses.
Last edited by OverKill; 02-04-2017 at 02:32 PM.
02-04-2017, 09:48 PM
#6
JK Enthusiast
Check the order in which you connected the harness to the Jeep behind the driver's side taillight. It can be connected two different ways but only one works as it should.
No flash required.
No flash required.
02-05-2017, 02:06 PM
#7
JK Newbie
Thread Starter
Solved
As most have suggested, no flash is required. Because the stop and turn signal lights from the harness were working and all other lights on the Jeep were working, I wrongly assumed it wasn't a blown fuse. As I was getting ready to pull the harness out I found the fuse for the harness itself and wouldn't you know it was blown. Replaced the fuse and now all works as it should! Now I just need to figure out why it blew in the first place. If the harness were just 6 inches longer it would make checking that fuse so much easier.
Thanks to all for your suggestions.
Thanks to all for your suggestions.