This forum has been great, and I've appreciated reading it seriously and leisurely, but I don't know what to do next with my problem -- my turn indicators won't work!!

It's a 1980 Ford F250, 6.6L. I've read all the posts and acted on them, including: Replaced all the front, rear and side light bulbs; replaced the flasher; replaced the turn indicator harness; checked and double checked the fuses; and untangled the interconnected mess of loose towing plug devices and took it back to just one.

Lights all work normally except for the indicators and the back up lights -- brake lights do work.

Can somebody suggest where to check next? This is my first car project ever, so it's all learning all the time -- and enjoyable at that -- but thank gawd it's not my daily driver.

Thanks.
Roger

 

The turn signal switch is complex and can cause problems. But, let's make sure we know the symptoms before diagnosing. Do the turn signal lights come on but don't flash, or do they not come on at all?

 

The turn indicator lights only come on when the headlights are turned on and then they they burn steady and don't respond to the turn indicator lever. No flasher noise.

I bought the new switch wiring from LCM, but the only obvious difference from the old one is that the new one had an additional separate wire with one bulb on it. I figure its for somewhere in the dash, but haven't got that far yet.

Roger

 

Some 1980 trucks are odd. The early ones had a different wiring system than the late 80's, 81's, and on. Here's the wiring diagram for the 1981 and later trucks. I'd check your wiring and wire colors against it and see if your truck is one of the odd ones. If so, the new wiring may not work for you.

 

Nice wiring diagram! I couldn't locate anything that detailed before. I will check the harness out. You have given me something specific to focus on ... I appreciate it. Thanks.

Roger

 

Do the green arrows in the dash come on but not blink? Or is everything black? The green arrows in the dash do not come on with the headlights do they?

 

When I first turn on the ignition nothing comes on except one light in the upper left hand corner which is one of the two "4X4" lights. Maybe the other bulbs are burned out. I'll replace those too and be able to give your question a better answer.

Roger.

 

I had a similar problem and it was the ignition lock. Turn on the signals and then move the lock a little to see if it helps. If so, then replace the lock for about 12 dollars. Just another item to check.

 

If this is the issue, then the blower will not work, either. It is not uncommon for the ignition to be sticky [more of an issue in cold climates].

 

The dash bulbs don't come on at all. It's all black. The Ignitions switch isn't very loose and doesn't seem to be affecting anything when I jiggle it. The blower motor works normally. I still have to look at my turn indicator wiring and compare it to the diagram that Gary sent. I'm hoping the problem is in there - not that that sounds easy to correct.

thanks for the additional input.

 

Look at the top left part of the diagram where the flasher is. That's where I would start. I would get a testlight and poke the flasher to make sure you have power there.

 

There is no power at the flasher base. I know that the wire colors on the original turn indicator switch are different than the new switch I put in, tho they both have nine wires. I'll work on understanding the wiring diagram vs reality this weekend so I can answer the question about wire colors/diagram.
Thanks,
Roger

 

I'm afraid your truck's wiring isn't the same as the later ones. Not sure what the differences are, but the early 1980 trucks were different.

 

You may be right. Sounds like a learning opportunity for me: jury rig the old switch, find one in a junk yard, or figure out how to rewire the new one -- any suggestion on those options?

In the meantime I'm hoping that someone on the forum who owns a 1980 truck also bought a switch from LMC and figured out the cure.

Thanks for your help - at least I'm focused on something specific now.

Roger

 

Well, it appears that your wiring must be the same as the later years as the Master Parts Catalog shows only one switch for 80 - 83. But, see the note about the speed control brushes - does your truck have speed/cruise control?