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

Go Back   Ford F150 Forum - Community of Ford Truck Fans > Late Model F150s > 2004 - 2008 Ford F150
Log In 

Help with turn signal / flasher

Thread Tools Search this Thread
Old 10-20-2009, 01:15 PM   #1
Junior Member
Join Date: Feb 2009
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
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
Join F150 Forum

Join Today - It's Totally Free!

Are you a Ford F150 fan? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's a great place for Ford F150 Fans to meet online.
Once you join you'll be able to post messages, upload pictures of your truck, and have a great time with other Ford F150 fans. Whether your an old timer or just bought your F150 you'll find that is a great community to join. Best of all it's totally free!

Join Today! - Click Here JOIN FOR FREE

Old 10-20-2009, 02:42 PM   #2
Senior Member
5 Year Member
thump's Avatar
Join Date: Jul 2009
Location: CO
Posts: 692
Thanks: 0
Thanked 9 Times in 2 Posts
Feedback Score: 0 reviews

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
5 Year Member
Bucko's Avatar
Join Date: Sep 2008
Location: Lake Mary Florida
Posts: 7,932
Thanked 196 Times in 164 Posts
Feedback Score: 0 reviews

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.
"Never argue with an idiot; they'll only drag you down to their level, then beat you with experience"

2007 F150 STX Supercab (4.6 2V V8), Edge tuner, factory navigation, H-D headlights, Mark VIII electric fan conversion with flex-o-lite controller.

Last edited by Bucko; 10-20-2009 at 02:53 PM.
Bucko is offline   Reply With Quote
Old 10-20-2009, 04:49 PM   #4
Junior Member
Join Date: Feb 2009
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
LED Turn Signals? Resistor? Flasher? NorCal_Fords 2015 - Present Ford F150 13 11-25-2015 01:54 PM
2004 Ford F150 Truck New Body Style Power Heated Turn Signal Upgrade Dual Arm Towing 1ATony Vendor Showcase 3 11-15-2015 07:31 PM
LEDs - Do Not Install Load Resistors for Hyperflashing! Dan2002 2009 - 2014 Ford F150 38 10-03-2015 12:29 AM
Rear lights don't work when lights are on. readyoarnot Electrical 2 09-08-2015 05:26 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 08:32 PM.

Copyright 2006 - 20011
This site is in no way affiliated with the Ford Motor Company.