No power to stop light switch
 

Hi guys

52 F1 all stock - 6 volt pos grd.

I got no power to my brake light switch. I just replaced the switch expecting it went bad but still no good.

All other lights work.

Need path forward. I don’t see any fuses and can’t seem find breaker.

Re: No power to stop light switch
 

Do you have a turn signal switch? If you have turn signals check to see if they are fused. The brake lights operate through the turn switch. The fuse to the turn switch could have blown or the turn switch itself could be bad.

Re: No power to stop light switch
 

Years ago one of the milk trucks at the dairy I worked at had an add on turn signal switch. If the switch lever wasn't perfectly centered between left and right the brake lights wouldn't work. Probably not the problem but you never know.

Re: No power to stop light switch
 

The truck did not have turn signals. I installed a seven wire turn signal switch after market. My turn signals are working.

Re: No power to stop light switch
 

Andy .....If, as you say the turn signals are working, and if you have your signal switch wired correctly, you can see that the brake light switch is fed power THROUGH your turn signal switch. I would test the junction where you wired the switch in at point of connection of line #5 to see if you have 6v at that point. Maybe that connection is loose, or worse. If you have no power at that point, there must be a "sneak circuit" or an "open" of some sort INSIDE the signal controller. Check-out this UNIVERSAL diagram. Let us know! DD


https://th.bing.com/th/id/R69b6d004b...sl=&pid=ImgRaw

Re: No power to stop light switch
 

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Also VERIFY that your NEW brake light switch actually works, open AND closed! DD

Re: No power to stop light switch
 

DD

Thanks. Yes I did check that. On mine it’s the orange eire(#5) there was no power to that. I also tried testing that line with pedal depressed. I got nothing. I have a brand new turn signal but was thinking…. Can I provide it with another hot lead? Or should I just put new seven wire in?

Forgive typos sent from phone

Re: No power to stop light switch
 

Electrically, I see no particular reason why you couldn't provide 6v to the #5 wire side of the switch, although your bulb will not BLINK if you have that turn bulb selected, AND the brakes applied. The bulb will stay on SOLID, rather than BLINK. I WOULD disconnect that #5 wire from the MAIN UNIT. You MAY want to throw a cheap fuse holder in that 'NEW' power circuit, as you should understand that the reason for a fuse is to protect WIRING....not that switch.
Personally, I would change-out the entire turn signal switch.
DD

Re: No power to stop light switch
 

I agree put new switch in. I would have liked to confirm bad switch first.

Re: No power to stop light switch
 

Adileo, in my thinking the signal switch doesn't come into play until the brake light switch sends power to it. You said you have no power TO the brake switch. Power to the brake light switch should stay hot all the time. If the feed to the brake switch doesn't check hot, you should find the open circuit or run a new hot wire to the switch.

Re: No power to stop light switch
 

If you look at the diagram the stop light switch gets its power from the
turn signal switch.

Re: No power to stop light switch
 

Did you check to see if the brake lights ever worked since you installed the turn signals? If they quit working after you installed the turn signals, something got wired incorrectly.

Re: No power to stop light switch
 

Denny, everything worked fine for over 3 years.

Bob, before I installed the turn signals. The stop switch was hot.

I’ll do more testing. I’ll find out why or use a new hot lead.

Re: No power to stop light switch
 

In the OEM diagrams for the 52 pickups, the stop light switch gets it's power from the lighting circuit breaker under the dash. It lists it as a green wire but these are cloth covered and may be in poor condition. The other wire from the stop light switch would have to go to the turn signal switch with them installed.
https://www.ford-trucks.com/forums/1...-question.html

Re: No power to stop light switch
 

The diagram says the side of the switch opposite the #5 wire goes to the battery. That means it is hot. When the switch is activated the current is routed to the brake lights according to the position of the signal switch.

Re: No power to stop light switch
 

Your right, need to put my glasses on.

Re: No power to stop light switch
 

40cpe is correct, and I AM FULL of it! I first looked at that circuit and ASSUMED (!!!) that "BATTERY" to the Brake Light Switch was a 'oopsie'. Sure enough, all of these Seven-Wire diagrams show TWO "hot" sources....one to the brake light switch, and a second one to the FLASHER. See below!! DD


https://i.pinimg.com/originals/d7/52...868a8ce238.png

Re: No power to stop light switch
 

double post

Re: No power to stop light switch
 

If a person doesn't use the OEM connection to the circuit breaker but connects direct to the battery then an inline fuse or the like should be used.