Help with turn signal / flasher - Ford F150 Forum - Community of Ford Truck Fans

2004 - 2008 Ford F150 General discussion on the 2004 - 2008 Ford F150 truck.
Sponsored by:
Sponsored by:

Help with turn signal / flasher

Thread Tools Search this Thread
Old 10-20-2009, 01:15 PM   #1
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Default Help with turn signal / flasher

Hey everyone... Have an issue, looking for some help.
have an 2004 F150 screw FX4
Drivers side turn signals are not working (front and rear). My flasher flashes really fast when the lever is activated to engage the driver's side turn signal. The passenger side works normal. I checked the bulbs, both front and rear are good. Checked fuses and both fuses (10 & 20 amp ) for the turn signal and flasher are good.
Here is where I am stumped !!!! When I attach my boat trailer or my other trailer and plug in my 4-wire adapter and connect my trailer lights. Everything works. I am thinking I may have a loose ground. Any suggestions???? Thanks a million for reading my post. I would welcome and appreciate any suggestions.
desert_Doc is offline   Reply With Quote
Old 10-20-2009, 02:42 PM   #2
Senior Member
thump's Avatar
Join Date: Jul 2009
Location: CO
Posts: 692
Thanks: 0
Thanked 14 Times in 5 Posts

When you say "checked you bulbs" did you just check if they light up, or actually pull them and look at the filaments? Many times the bulb is dual-filament and it will start "fast flashing" when just one of them breaks, but the bulb will still light.
thump is offline   Reply With Quote
Old 10-20-2009, 02:48 PM   #3
Moderator (Ret.)
Mod (Ret.)'s Avatar
Join Date: Sep 2008
Location: Lake Mary Florida
Posts: 9,444
Thanked 427 Times in 338 Posts

Either one of the bulbs on the drivers side is not making a good connection to the bulb socket, or the wire(s) to the flashing filiment of the bulb is open.

In the rear, the bulb has two filiments; one is the parking light, the other is the turn signal (flasher circuit).

The front uses also uses a double filiment as well. So, even though the bulb filiments are good, the posts are not making good contact in the base, or there is a broken wire on the circuit.

For craps and giggles, have you tried swapping the left side bulbs to the right side? Sometimes the filiments look like they're good, but there could be a break that even good eyes don't see.. Use an ohm meter to be sure, or swap the left with the right.

If you are sure that the bulbs are good, then remove the drivers side taillight assembly and look for a broken wire there. If not, remove the drivers side headlight assembly and look there.

Last edited by Mod (Ret.); 10-20-2009 at 02:53 PM.
Mod (Ret.) is offline   Reply With Quote
Old 10-20-2009, 04:49 PM   #4
Junior Member
Thread Starter
Join Date: Feb 2009
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts

Thanks a million for the advice guys... I went ahead and swapped out the bulbs from the passenger rear to the drivers rear and the trouble then switched to the passenger side ( Fast clicking ) So I went down to the auto parts store and bought new bulbs... Installed new bulbs and now truck and owner are both happy...

Problem resolved.... Thanks a million for your advice...
desert_Doc is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
2004 Ford F150 Truck New Body Style Power Heated Turn Signal Upgrade Dual Arm Towing 1Aauto Vendor Showcase 23 11-18-2017 07:03 AM
LEDs - Do Not Install Load Resistors for Hyperflashing! Dan2002 2009 - 2014 Ford F150 41 05-09-2017 12:41 AM
LED Turn Signals? Resistor? Flasher? NorCal_Fords 2015 - Present Ford F150 47 04-08-2017 09:23 AM
Rear lights don't work when lights are on. readyoarnot Electrical 4 02-09-2016 06:29 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 12:57 PM.

Copyright 2006 - 2017 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 and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: