2004 expedition turn signal problem

flattire

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#1
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MAKE:Ford
MODEL:Expedition
YEAR:2004
MILES:146,000
ENGINE:5.4
DESCRIBE ISSUE....Turn signals work ok sometime then quit. Manually clicking the lever will light both front and back turn signal lamps and usually after a few seconds all is well once again for a while then we might get a repeat. We have gone all day with them working perfect but not often. Comments appreciated. Thanks
 

billr

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#2
When they don't flash properly, do the lights stay on, or stay off?
 

nickb2

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#3
Most probably a faulty electronic flasher relay or a multifunction switch.

But first, when the flasher is working, wiggle test the harness from the function switch to the relay box, then wiggle test the four corners of the truck on the turn signal harnesses, If the flashers do not cut out at this point, check all the connectors for corrosion, if all is good, time to swap the relay, if that does not help, then most likely a function switch.

If you are adpet with a multimeter, here is a pin test chart to test the relay and multifunction switch.

See ACE0 pdf below.
 

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#4
I agree - and would look at the flasher relay first.... the bulbs always come on but not always flashing SO-
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