Electrical problem - Ford Truck Enthusiasts Forums

2004 - 2008 F150 2004, 2005, 2006, 2007 and 2008 Ford F150's with 5.4 V8, 4.6 V8 engine

Electrical problem

Old 02-27-2015, 12:05 AM
fp_5's Avatar
fp_5 is offline
Posting Guru
Thread Starter
Join Date: Sep 2004
Location: Ajax, Ontario, Canada
Posts: 1,158
fp_5 is gaining momentum as a positive member of FTE.
Electrical problem

I usually engage in the '73-79 forum or my local chapter but...I just picked up a 2004 F150 FX4 Supercab, I had a safety inspection done and am working through some of the issues. What I thought would be an easy fix has me scratching my head....
The turn signal indicator on the passenger side mirror is not working(front and rear indicators work). I took the mirror apart and get no voltage to the led array, next I pulled the rubber boot off of the harness in the door jam and probed the wires while with a test light and found one of the wires would blink the test lest light but the colour didn't match the the turn signal array, it matched the heated mirror wire. I probed at the heated mirror connector at the mirror and sure enough it blinks! WTF? Then i notice that the heated mirror indicator light on the center dash is blinking? I push the heated mirror button below the indicator light and ALL turn signals (front and rear) stop.

I searched the forum for mirror turn signal issues and found a thread about corroded wire splice below the fuse panel. I checked and have no splice all look ok so I thought I would post and see if I can get some direction or a schematic.

The symptoms are :

_Passenger side mirror turn signal(right turn) indicator does not work
- front and rear turn signal indicators work
- power seat works
-fuses are good
- drivers side all turn signals work fine
- heated mirror indicator light on the dash blinks with the passenger side turn signal
- pushing the heated mirror button when turn signals are flashing (right turn) results in a solid heated mirror indicator light but all other right turn signal indicator stop blinking (off)

Any help would be appreciated. It seems to me that there must be a short between the two circuits but where?

Old 03-02-2015, 05:42 PM
Oldguy4 is offline
Elder User
Join Date: Jul 2008
Location: Newport, Wa.
Posts: 554
Oldguy4 is starting off with a positive reputation.
I think you are right. The two circuits are crossed. Have you checked the plug for the heated mirror switch? The passenger side mirror turn signal might run through there.
Related Topics
Thread Starter
Last Post
2004 - 2008 F150
04-14-2017 02:00 PM
1999 to 2016 Super Duty
04-01-2017 07:30 AM
1999 to 2016 Super Duty
03-13-2017 07:52 AM
1973 - 1979 F-100 & Larger F-Series Trucks
08-26-2016 06:36 PM
Excursion - King of SUVs
06-14-2016 09:02 PM

Thread Tools
Search this Thread
Quick Reply: Electrical problem

Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.