1973 mustang issues with brake light switch power

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ustang73

Member
Joined
Feb 20, 2016
Messages
16
Reaction score
0
Location
Pennsylvania
My Car
1973 Mustang Convertible 302 auto
I'm having a brake light issue with a 73 mustang convertible. The previous owner added a lot of extra blue lights and stereo gear. In the process he cannibalized some of the wiring and now the brake lights and hazards don't work. I have removed all this added on extra stuff.

The issue is that there is no power to the green with red dash striped wire that feeds the brake light switch which then seems to lead to the hazards. They spliced a pig tail into the green red stripped cable from another source to make it work. This has since broken off, when I removed all the after market lights and stereo amps.

I pig tailed a wire in from the fuse box to at least get some power so brake lights and hazards work if the key is on.

If anyone can point we to why power on the green wire with red dashes to the brake switch light is not working would be appreciated. I have the wiring diagrams but the wire that feeds to the brake lights switch seems to be the best kept secret I have found on the net.

Thanks....

 
Interesting, if I am looking at what you are describing there is a stop lamp circuit breaker located on the relay panel above the glove box. Connector C-604 connects to this CB, one pin has the green with red dash striped wire and the other pin has a yellow wire. The yellow wire provides the power through that circuit breaker. Not sure how much of the wiring is hacked up but I would probably check if that CB is good or they removed the connector. Follow the wire from there to the stop lamp switch to see if the wire was cut. If you have a voltmeter check for voltage coming out that CB to ensure it is still good..

As I was looking at this I remembered Timachrome was working to identify all the relays on the relay board. Go to this thread and relay #2 is the one you are concerned about.

https://7173mustangs.com/threads/what-are-these-relays-for.16407/
 
Last edited by a moderator:
John, thanks a million. I found the panel above the dash and the wire fell out of the CB. Once I plugged her in I was in business!!

I didn't realize there was a panel ABOVE, I took the glove box out over the weekend but never took that plate off on top.

Included a pic of the car. I need to do some work, there is a lot of add on badges that don't belong and some interior stuff as well. Just had the trunk floor, fuel system and tank redone so at least it's solid now underneath.

Thanks Again,

Dave

Interesting, if I am looking at what you are describing there is a stop lamp circuit breaker located on the relay panel above the glove box. Connector C-604 connects to this CB, one pin has the green with red dash striped wire and the other pin has a yellow wire. The yellow wire provides the power through that circuit breaker. Not sure how much of the wiring is hacked up but I would probably check if that CB is good or they removed the connector. Follow the wire from there to the stop lamp switch to see if the wire was cut. If you have a voltmeter check for voltage coming out that CB to ensure it is still good..

As I was looking at this I remembered Timachrome was working to identify all the relays on the relay board. Go to this thread and relay #2 is the one you are concerned about.

http://www.7173mustangs.com/thread-what-are-these-relays-for
IMG_1368.JPG

 
Last edited by a moderator:
Interesting, if I am looking at what you are describing there is a stop lamp circuit breaker located on the relay panel above the glove box. Connector C-604 connects to this CB, one pin has the green with red dash striped wire and the other pin has a yellow wire. The yellow wire provides the power through that circuit breaker. Not sure how much of the wiring is hacked up but I would probably check if that CB is good or they removed the connector. Follow the wire from there to the stop lamp switch to see if the wire was cut. If you have a voltmeter check for voltage coming out that CB to ensure it is still good..

As I was looking at this I remembered Timachrome was working to identify all the relays on the relay board. Go to this thread and relay #2 is the one you are concerned about.

http://www.7173mustangs.com/thread-what-are-these-relays-for
I am running into the same issue, but the link to the thread you posted is no linger there. Still trying to find the power source for my brake lights and the circuit breaker. Thanks
 
Back
Top