turn signal mayhem

[jrizzyreal]

ok so my girl has an 04 1500 runs strong but is an electrical nightmare and she refuses to get rid of it so I'm the luck one who gets to fix it. currently the biggest issue is the rear turn signals don't work. put on the left or right and the front rapid flashes like the rear is burned out but they're not. also when you put the headlights on the tail lights light up as though you're on the brake the high mount works normally. and this is the best part if you put the hazards on everything flashes in the rear including the plate lights. i've checked fuses and grounds and the multifunction switch all seem to be fine but this truck is possessed. I'm about to bypass everything and rig the left and right signal to their own toggle switch to the flasher relay so those at least work n she doesn't get pulled over (I know I know that's Uber hillbilly of me but idk what else to do) and probably run new wire for the brake lights. any suggestions as to the real problem would be appreciated but i'll be needing some wiring diagrams as well since i'd like to not cut the wrong wires

 

[markabby]

i wouldn't run new wires.

look at wiring diagrams for the tail lights and be sure the correct wire is used for brake and tail lamps.

are there LED lights installed? sometimes LEDs do rapid flashing. when turn signals are on, did you check the rear wires for power? If after checking the correct turn signal wire and there is no power, i'd go back to the fuse box and check power at both relay and fuses.

Also, bad grounds wreak havoc on wiring

2004 Dodge Ram 1500 fuse box diagram - StartMyCar

Complete fuse box diagram for the 2004 Dodge Ram 1500. Find fuse locations, amp ratings, and descriptions for all fuse boxes.

www.startmycar.com

 

[PolarisCobra]

When was the last time it worked right? What was done since that time?

This is likely something simple. I would consider new bulbs. Make sure they are installed correctly. Not LEDs, standard bulbs. Don't take the old bulbs for a match, go to the counter at the parts store, and ask them to look up the number, it may have incorrect bulbs in there now.

 

[MrBonez]

i wouldn't run new wires.

look at wiring diagrams for the tail lights and be sure the correct wire is used for brake and tail lamps.

are there LED lights installed? sometimes LEDs do rapid flashing. when turn signals are on, did you check the rear wires for power? If after checking the correct turn signal wire and there is no power, i'd go back to the fuse box and check power at both relay and fuses.

Also, bad grounds wreak havoc on wiring

2004 Dodge Ram 1500 fuse box diagram - StartMyCar

Complete fuse box diagram for the 2004 Dodge Ram 1500. Find fuse locations, amp ratings, and descriptions for all fuse boxes.

www.startmycar.com

This is a likely suspect with what's going on.
If it loses ground to the rear lighting harness it can cause all kinds of things to act up or not work.

An old S10 I owned years ago had this problem and nothing worked with my tail lights - And I mean nothing.
The dash/insturment panel lights didn't work either and after some real head scratching it was found the harness ground wire to the frame had corroded and simply broke off, repairing it got it all working again.
Be sure to check that concerning the rear lighting harness because a bad ground can drive you crazy sometimes.

 

[BillLee]

Do you know the true history of the truck? Have you found sediment in strange places? If it is a flood truck, all bets are off.

 

[js12278]

Definitely check all grounds. Look at all bulbs on circuit for corrosion.

 

[Marshall]

You have to crawl around under it and check every inch of the wiring harness, and where it crosses frame members for shorts, green wire and poor connections, both hot and grounds. the brake light and turn signal are the same line. Really check around back end , and the trailer cck's if you have trailer plugs and pull the tail lights out and check the back end of the sockets and if the sockets are all rusty, fix or replace.

You could run new wire, but that may just put off the proper fix.