E350 - Wierd Turn Signal Issue

ford
electrical-wiring
e350

#1

I have a class C motorhome built on a 1994 Ford E350 chassis. The right front turn signal bulb will not flash and the right rear bulb flashes extra fast. But, all four bulbs (left and right, front and rear) flash normally when I turn on the emergency flashers. In addition when driving on cruise control, turning on the flashers or the left turn signal will disengage the cruise. Can someone please advise on what is causing these issues? Thanks in advance.



- Jeff in Seattle


#2

Problem 1: Your front right bulb is burned out, your bulb socket is bad, or the wiring going to the bulb is cut somewhere. There is no mystery as to why the rear bulb is flashing twice as fast as it normally would. This is a built-in (to the flasher) warning to you that you have a bulb out. Read the owner’s manual, it’s in there.

Problem 2 (cruise cuts off): Your left turn signal is shorted somewhere to the brake lights.


#3

Tardis: Thank you for your response…

The thing is, the bulb, socket, and wiring cannot be bad as the bulb works on flasher just not turn signal. Do you think a short in the turn signal switch itself could cause these issues?


#4

In that case, it is your multi-function switch or your hazard light switch. In most cases for Ford, the hazard light switch is a part of the multifunction switch. If this is not true in you case, then just change the hazard light switch. It likely has a bad contact in it.
(This is not a “short”, it’s an “open.”)


#5

Jeff,
I have a 1996 class C on an E-350 with similar problems. I have discovered it seems to be related to the multi-function switch (turn signal/wiper/washer/four way hazards). My brake lights would not work when the right turn signal was on. The four ways also would not work. Spraying the switch with contact cleaner and working it many times seems to have cleaned up the contacts, at least temporarily. I think the permanent fix is to have the unit replaced.