Lighting Issues- Please Help!
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Lighting Issues- Please Help!
Hello all, new to the forum as a member, but have been reading for a long time. Lots of good info on here, however I cannot seem to find the answer or any information on this specific issue. Any help is greatly appreciated!
1979 F-350 Camper Special
2wd, 400M, 4-speed manual
Having problems with the park lights, side markers, turn signals and such.
New trailer tow relay, as well as turn signal and hazard flasher cans
When the brake pedal is pushed down, the clearance lights, cab lights, side markers, taillights, and even license plate light come on!
The right turn signal functions properly, however when I use the left turn signal, it flashes all of the clearance lights, cab lights, side markers, taillights, and license plate light, in time just like the turn signal would flash.When the park lights are on, and the brake pedal is pushed down, both turn signals front and rear all light up brighter at the same time. Also when the lights are on and I use the left signal, it flashes the park lights, cab lights, and sidemarker lights on and off. Also the trailer tow relay can be heard clicking (brand new). Any help would be greatly appreciated, as the pickup is not driveable the way it is!
1979 F-350 Camper Special
2wd, 400M, 4-speed manual
Having problems with the park lights, side markers, turn signals and such.
New trailer tow relay, as well as turn signal and hazard flasher cans
When the brake pedal is pushed down, the clearance lights, cab lights, side markers, taillights, and even license plate light come on!
The right turn signal functions properly, however when I use the left turn signal, it flashes all of the clearance lights, cab lights, side markers, taillights, and license plate light, in time just like the turn signal would flash.When the park lights are on, and the brake pedal is pushed down, both turn signals front and rear all light up brighter at the same time. Also when the lights are on and I use the left signal, it flashes the park lights, cab lights, and sidemarker lights on and off. Also the trailer tow relay can be heard clicking (brand new). Any help would be greatly appreciated, as the pickup is not driveable the way it is!
FTE Legend
Joined: Nov 2015
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From: Angier, NC
I have see where the filament breaks and falls across the other and causes crazy issues like this also.
Dave ----
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FTE Legend
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From: Angier, NC
@fuzzface
Just came in from checking that out, did not change anything, however thank you for your input, and any other ideas would be great!
Just came in from checking that out, did not change anything, however thank you for your input, and any other ideas would be great!
I would do either just to make sure if you did not.
I will go back over your post to see if anything else pops out at me.
Dave ----
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From: Angier, NC
Ok when did this all start happening?
Was everything working good and then you went and did all of the NEW STUFF all at once?
It is sounding like that new turn signal switch is either bad or wired wrong but I would go with bad.
What if you take the tow relay out of the picture?
I would not just unplug the relay but undo any of the wiring so its not hooked up to the truck and see if the problem still happens.
Dave ----
Was everything working good and then you went and did all of the NEW STUFF all at once?
It is sounding like that new turn signal switch is either bad or wired wrong but I would go with bad.
What if you take the tow relay out of the picture?
I would not just unplug the relay but undo any of the wiring so its not hooked up to the truck and see if the problem still happens.
Dave ----
Fleet Mechanic
Joined: Sep 2009
Posts: 1,572
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From: Northern Virginia.
Check all light bulb sockets for rust on the bulb contact points.
Clean them all.
https://www.ford-trucks.com/forums/1...tmas-tree.html
Clean them all.
https://www.ford-trucks.com/forums/1...tmas-tree.html
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@i-w
Thats a good video, the grounds in those sockets can be big trouble, had to cut open the plugs and solder the tangs in on my ‘77 and the lights work great!
@FuzzFace2
Everything was working perfectly fine last summer, and then one day it started doing this. The flasher cans were both replaced first, and then the trailer tow relay, since that was flopping around under the dash. Those parts were replaced AFTER this started happening. This is very confusing, since it only happens when the brake pedal is pushed, and the left signal is used. Could it be the original turn signal switch, since all the signals and brake lights run through that?
I took the bulb completely out of the socket, tried it, nothing changed. I took the front one out as well. No change. Both bulbs looked good, nothing was broken, I shined a flashlight through them and got a good look. The turn signal switch is the original, was not replaced, just the flasher cans and the trailer tow relay have been replaced. All the sockets on the pickup were cleaned and re greased with dialectic grease, also this pickup is never driven in the winter, and almost never in the rain or any wet roads.
I really appreciate your time and thoughts!! We may get this figured out yet!
Thats a good video, the grounds in those sockets can be big trouble, had to cut open the plugs and solder the tangs in on my ‘77 and the lights work great!
@FuzzFace2
Everything was working perfectly fine last summer, and then one day it started doing this. The flasher cans were both replaced first, and then the trailer tow relay, since that was flopping around under the dash. Those parts were replaced AFTER this started happening. This is very confusing, since it only happens when the brake pedal is pushed, and the left signal is used. Could it be the original turn signal switch, since all the signals and brake lights run through that?
I took the bulb completely out of the socket, tried it, nothing changed. I took the front one out as well. No change. Both bulbs looked good, nothing was broken, I shined a flashlight through them and got a good look. The turn signal switch is the original, was not replaced, just the flasher cans and the trailer tow relay have been replaced. All the sockets on the pickup were cleaned and re greased with dialectic grease, also this pickup is never driven in the winter, and almost never in the rain or any wet roads.
I really appreciate your time and thoughts!! We may get this figured out yet!
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@FuzzFace2
Also, I will try some different things tomorrow, new bulbs, eliminating the trailer tow relay from the pickup completely and see what happens.
Do you know what the trailer tow relay does/is for? I would assume something with a trailer, but I don’t know exactly what it all does. What effect might this have on the lighting?
Also, I will try some different things tomorrow, new bulbs, eliminating the trailer tow relay from the pickup completely and see what happens.
Do you know what the trailer tow relay does/is for? I would assume something with a trailer, but I don’t know exactly what it all does. What effect might this have on the lighting?
Lead Driver
Joined: Jul 2017
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From: San Jose, CA
I know you said everything was working fine before XL5 (Fireball, by any chance?
), but what is the overall condition of the wiring of your truck?
If it's been hacked a lot by PO's, maybe you were just lucky that it worked as long as it did. But if it's in pretty pristine shape, then maybe that'll help narrow down the problem to grounds and such. Although I have to admit that it's an odd issue. Not sure I've seen a brake light switch do as much as yours before!
Not without lots of help by the PO that is.
Good luck.
Paul
), but what is the overall condition of the wiring of your truck?If it's been hacked a lot by PO's, maybe you were just lucky that it worked as long as it did. But if it's in pretty pristine shape, then maybe that'll help narrow down the problem to grounds and such. Although I have to admit that it's an odd issue. Not sure I've seen a brake light switch do as much as yours before!
Not without lots of help by the PO that is.
Good luck.
Paul
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@1TonBasecamp
The wiring in the pickup is pretty good, it belonged to my grandfather, and has about 78,000 original miles on it. However a few of his sons may have gotten into the wiring on it for any number of reasons untold.
I’ll be checking into some more grounds today, and possibly the trailer plug, as I am pretty sure that could’ve been hacked in!
thanks for all the help guys! Hopefully we’ll get this figured out!
The wiring in the pickup is pretty good, it belonged to my grandfather, and has about 78,000 original miles on it. However a few of his sons may have gotten into the wiring on it for any number of reasons untold.
I’ll be checking into some more grounds today, and possibly the trailer plug, as I am pretty sure that could’ve been hacked in!thanks for all the help guys! Hopefully we’ll get this figured out!
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From: Angier, NC
I thought the turn switch was also replaced? my bad 
Yes that could be the reason for the issues as you said everything kind of goes thru it.
You might be able to take contact cleaner and spray it in to the switch and work the switch and see if that does anything.
Just got to thinking (yes it hurt
) thing is why the running lights flash as no running lights wiring goes thru the turn switch?
Going to have to think more on this one ...ouch!
I think I would pull all the fuses and clean the ends and holders.
I would then install 1 at a time and test what you get,
Think I would start with the turn signal fuse first and see what happens.
Trying to think where the turn wire and running light wires run close together? Fuse box maybe?
Dave ----
Yes that could be the reason for the issues as you said everything kind of goes thru it.
You might be able to take contact cleaner and spray it in to the switch and work the switch and see if that does anything.
Just got to thinking (yes it hurt
) thing is why the running lights flash as no running lights wiring goes thru the turn switch?Going to have to think more on this one ...ouch!
I think I would pull all the fuses and clean the ends and holders.
I would then install 1 at a time and test what you get,
Think I would start with the turn signal fuse first and see what happens.
Trying to think where the turn wire and running light wires run close together? Fuse box maybe?
Dave ----