New Electrical Issue

[icanfixall]

So after the exhaustion of "finding" the cold advance fast idle coolant sensor turned out to be causing all my issues today I tried using my turn indicators but nope. No joy. I have power to the number 5 fuse in the main box. Only the right rear stop light will flash when the emergency flashers are on. If I turn on my head lights both of my front marker which are also the flasher lights come on.But no flashing or turn indicators. Any ideas??? I know I can drive this way but its really not what I like to do especially when I have "other means" of transportation...Electrical issues are killing me. I hope I can start at the last item this time instead of going thru all the mess of a track down...

 

[IDIBRONCO]

I don't know if this is even a remote possibility, but have you tried replacing the flasher? I don't know if it could only send power to one corner of the truck, but it's a cheap thing to try.

 

[madpogue]

The front parking lights are NOT on the same circuit as the turn signals / emergencies. It's the same bulb, but two separate filaments, fed by two separate circuits. The emergencies and directionals do feed the same circuit/filament, however.

There are two flashers, one for the directionals and one for the emergencies. On the OBS and bullnoses, they're both in the fuse box. Directionals is the flasher that you can see, and emergencies is the one on the "blind" side of the box. Leave it to Ford, on the bricknoses, they put the emergency flasher button all by itself over on the passenger side of the dash. IIRC, you have to open or remove the glove box.

The other prime suspect is the turn/emergency switch on the column. Lots of contacts making/breaking based on on/off positions. And the icing on the cake is that for the rear, the brake light circuit is also in the mix.

 

[icanfixall]

Replaced the flasher but same issue. A 14 buck not needed item but well its new now. Seems this is a deep issue to figure out.

 

[madpogue]

Which flasher did you replace?

 

[laserjock]

So after the exhaustion of "finding" the cold advance fast idle coolant sensor turned out to be causing all my issues today I tried using my turn indicators but nope. No joy. I have power to the number 5 fuse in the main box. Only the right rear stop light will flash when the emergency flashers are on. If I turn on my head lights both of my front marker which are also the flasher lights come on.But no flashing or turn indicators. Any ideas??? I know I can drive this way but its really not what I like to do especially when I have "other means" of transportation...Electrical issues are killing me. I hope I can start at the last item this time instead of going thru all the mess of a track down...

It’s bizarre to only have one particular bulb flash. Do the stop lights work. If memory serves, the stop/haz lights are on one fusible link. Seems to me that the turns are actually on a different circuit. The common link here is turn signal (sometimes called multifunction) switch under the steering wheel. First I would do the stupid thing and check the bulbs. If they are good, check for power at the sockets with the flasher on and start working your way back. The haz flasher and horn relay are up behind the glove box. Why, I have no idea.

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That’s the flasher the horn relay is sorta in the foreground. I guess ford had a few extra miles of wire they needed to consume. Only reason I can think of for putting it there.

The curious thing is that you say the one rear light flashes. To me that’s bizarre because if the rear flashes so should the front. Are the indicators in the dash flashing? If they are flashing, sounds to me like maybe a goofy situation where the other bulbs are trying to flash but something is shorted out or there is not enough power to light them enough to see them like a link wire again).

You certainly have a knack for bizzare wiring problems Gary.

 

[laserjock]

So after the exhaustion of "finding" the cold advance fast idle coolant sensor turned out to be causing all my issues today I tried using my turn indicators but nope. No joy. I have power to the number 5 fuse in the main box. Only the right rear stop light will flash when the emergency flashers are on. If I turn on my head lights both of my front marker which are also the flasher lights come on.But no flashing or turn indicators. Any ideas??? I know I can drive this way but its really not what I like to do especially when I have "other means" of transportation...Electrical issues are killing me. I hope I can start at the last item this time instead of going thru all the mess of a track down...

It’s bizarre to only have one particular bulb flash. Do the stop lights work. If memory serves, the stop/haz lights are on one fusible link. Seems to me that the turns are actually on a different circuit. The common link here is turn signal (sometimes called multifunction) switch under the steering wheel. First I would do the stupid thing and check the bulbs. If they are good, check for power at the sockets with the flasher on and start working your way back. The haz flasher and horn relay are up behind the glove box. Why, I have no idea.

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That’s the flasher the horn relay is sorta in the foreground. I guess ford had a few extra miles of wire they needed to consume. Only reason I can think of for putting it there.

The curious thing is that you say the one rear light flashes. To me that’s bizarre because if the rear flashes so should the front. Are the indicators in the dash flashing? If they are flashing, sounds to me like maybe a goofy situation where the other bulbs are trying to flash but something is shorted out or there is not enough power to light them enough to see them like a link wire again).

You certainly have a knack for bizzare wiring problems Gary.

 

[DaveBen]

This sounds like a turn switch problem (oh boy!).

 

[icanfixall]

The flasher I replaced was in the main fuse box under the dash at the drivers side. Had no idea we have a flasher near the glove box too. The ONLY light working when the emergency flashers are on is the right rear stop light. Neither of the dash flasher lights are working. If I turn on the head lights both of the front marker lights that also are the flasher lights up front are on. High beams work too.Radio works as do the windshield wipers. Door locks working fine as are the electric windows. Have not tried the horn yet but will today. Dash lights are fine. Wait to start light works too. Dis connected the water in fuel light long ago. Fuel heater also not connected. Never found a reason for a heater ON TOP of anything worth a damn.Don't we always heat something from the bottom??? Ok maybe we broil steaks or chicken when the heat on top but thats all I know of...

 

[laserjock]

What’s the condition of your trailer plug? I know it’s random but a messed up trailer plug might play into this. Also I know it sounds stupid but check the bulbs. You may be fighting a battle on multiple fronts here. Cross off the easy things first.

I can’t come up with a logical reason why the one rear tail light flashes. That is baffling. I almost wonder if there is a short somewhere back there and it’s backfeeding because it’s close to the short. Is it bright like it should be when it flashes?

Hazards/brakes are fed via fusible link - I don’t think there is a fuse but not sure. The turns are fed via a different source - pretty sure it’s on a fuse in the panel.

Like said above, your marker lights are independent. It’s a 3157 bulb with two filaments. One running light, one flasher/turn signal.

Does your brake controller flash with the hazards on? Unless someone put a diode in the signaling chain from the stop lights switch, it will flash the brakes as the hazards flash because it back feeds to the stop light switch.

I’m leaning toward turn signal switch too but it doesn’t hurt to isolate as many other things as possible because changing the turn signal switch is not trivial. I can walk you through taking the connector apart to feed it through the column if it comes to doing it. You will also need a steering wheel puller.

 

[jrad235]

I third the turn signal switch. buy a Motorcraft one if you can.

 

[icanfixall]

Thanks for the info bout the marker lights being a two filament bulb. Up front they are easy to remove and check... I think....Funny thing is I have one flashing light in the rear when the flashers are on..I too am leaning towards the turn signal switch in the steering column..sure hate to dig into that area.I did drop the column to replace a suspect ignition switch when all this was happening. It felt funny for bout a year. Not expensive either. Glad it was not impossible to install too.Made several adjustments before column was bolted back up in place. May have to drop it again if the turn indicator switch needs replacing. A

 

[laserjock]

You don’t have to drop the column.

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Unplug it and pop the little red plastic but out and you can slide the pins out. That will let it slip up through the column. Same with the re-install.

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Here’s the colors and locations for reference.