Old Truck Turn Signals Only Kinda Work

Lanse · Jan 11, 2017

Hey everyone! I was wondering if anyone had any knowledge of working on turn signal lights. I'm fixing up a 1984(?) Ford F700 Dump Truck and the turn signals work
perfectly indicating a left turn, but dont work hardly at all for a right hand turn.

When you actuate the lever, nothing happens unless you wiggle it quickly in which the turn signals will flash one time. Its like theres a dirty connection somewhere, but I dont
even know where to check! Both bulbs in the turn signals themselves work just fine. Any advice? Thanks in advance.

Dick2 · Jan 11, 2017

The first thing to check is ALL grounds. Next would be contacts in the main switch. Use a volt meter to see how much current you have on each side.

gene bender · Jan 11, 2017

30 pluss yrs old probably has dirt in lotsd of places get a bomb of electrical cleaner and spray around that just mite clean some contacs

Mike M · Jan 11, 2017

My 1981 F350 has that problem on the left signals. If you wiggle it or hold it up slightly it works. I think it may be better since I worked it up and down a lot. Likely corroded up.

john *.?-!.* cub owner · Jan 11, 2017

Might try pulling the 4 way flasher knob out and pushing it back in, in addition to using the spray cleaner. On that old a model the 4 way button slid contacts in and out under the signal lever contacts. Good possibility the contacts are worn out though, and if so not that hard to change, but you do need a steering wheel puller to do it. At least you don't have to worry about the air bag while pulling the steering wheel.

rustyfarmall · Jan 11, 2017

The turn signal switch used to be one of those items that wore out rather quickly. With all the contacts, springs, and detents, there really is no fix. Just pull the steering wheel and replace the switch. Probably get one at N.A.P.A.

Dick L · Jan 11, 2017

Over the years most of my turn signal problems have been, as Dick2 said, ground problems on cars, trucks and trailers. Any wire connector can be a problem as well as the switch. Jump a hot wire to the wire leaving the flasher going to the light in question. You should be able to tell that way which side of the flasher your problem exists.

Janicholson · Jan 11, 2017

If the wires to the lights are shorted, it might act like that, keeping the flasher "open". To test it I would put the lever in the center (not left or right) and use a test light (not meter) going from a 12v source to the bulb contact at the bulb socket. The lamp should not light. This also needs to be done from the other bulb on the opposite end of the truck. If the bulb lights, there is a ground where it does not belong. (make sure you are on the correct terminal in the socket). Jim

jr1983 · Jan 11, 2017

No use in checking anything. The contacts are dirty. Standard problem on all fords from 1993 back. You can change the switch or you can spray brake cleaner in the gap between the steering wheel and column and work the switch back and forth reply fast. Usually works.

gene bender · Jan 11, 2017

Why would you use brake cleaner on electrical parts when they make cleaner for electric contacs.

Old Truck Turn Signals Only Kinda Work

Lanse

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Dick2

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gene bender

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Mike M

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john .?-!. cub owner

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rustyfarmall

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Dick L

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Janicholson

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jr1983

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gene bender

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