Blinker and Brake Light Issues

[SSSSParky]

Hi Everyone, Hope someone out there can help. I've searched the site but have not been able to find the same issue. I recently purchased a '74 F250 that had/has several issues but slowly but surely I'm getting them taken care of but now I found that I've been driving around with some electrical issues I didn't know I had. So this is what's happening:

My brake lights work without any issues unless either of my blinkers are in use. My blinkers work great unless I depress my brakes. Once I have a blinker blinking and depress my brakes the brake light dims and blinks very slowly, my blinker stays lit and blinks at its normal rate. This is the case whether I use the left or right blinker. Only other electrical issues I have is my dash gauges (oil, fuel and temp) don't work so I installed a below the dash set. All other lights (dash, heater indicator, glove box, headlights and running lights) work without any issues.

If you need any further information please let me know. Thanks in advance

 

[Fellro]

It could be as simple as a ground issue for the cluster, which the lack of functional gauges kinda points that way. Thing is, which lights are blinking slow, the tail lights, or the dash? If tail, then I would look at the turn signal switch as possibly the issue. Flasher also is suspect since it affects both sides.

 

[SSSSParky]

Thanks, the blinkers are blinking at a normal rate but the brake lights are also blinking but at a slower rate and also dim. I'll check out to see if the dash lights are blinking but don't believe so.

 

[SSSSParky]

Dash lights do not blink, only rear blinker and brake lights.

 

[keithgonzales]

Look at your grounds.

 

[Mil1ion]

Your problem is the lightbulb sockets.
Grounding is reversing from one system to the other.
Everything runs through the turn signal switch.

Perhaps someone installed a bulb incorrectly.
You have to take the time to make sure all bulbs are inserted correctly and all ground wires behind the taillights are clean and secure before you move to test procedures.

 

[SSSSParky]

Your problem is the lightbulb sockets.
Grounding is reversing from one system to the other.
Everything runs through the turn signal switch.

Perhaps someone installed a bulb incorrectly.
You have to take the time to make sure all bulbs are inserted correctly and all ground wires behind the taillights are clean and secure before you move to test procedures.

Thank you, I will need to remove my camper than I'll check out the connections.

 

[DNFXDLI]

This manual might help you as well, it's for a 79, but the same principles apply.

http://www.fordtruckfanatics.com/forum/showthread.php?t=29167

 

[SSSSParky]

Thank you, I will need to remove my camper than I'll check out the connections.

I got my camper off and cleaned up all the grounds and sockets, this took care of the problem with the truck. Found I had the same issue with the camper when I plugged it in so I cleaned up all the grounds, added a ground and now all lights, blinkers and flashers are working as they're suppose to on both the truck and camper. Thanks for the suggestion, very much appreciated.

 

[SSSSParky]

This manual might help you as well, it's for a 79, but the same principles apply.

http://www.fordtruckfanatics.com/forum/showthread.php?t=29167

Thanks for the manual, was able to look it over quickly before the grandkids showed up but will read it in depth tomorrow as it looks like it will answer some other questions I have.

 

[Mil1ion]

Glad you're back to square one.