Brake Lights

[gt_orange]

I have a 2000 gt mustang, bought the car in 2006, today I noticed the brake lights are not working, the flashers/headlight/parklights all work. the third brake light works when brake is applied. fuses as all in working order, cruse control works aswell. any ideas??

 

[phatboy5015]

If the third brake light works, it's probably just bulbs.

 

[wmburns]

Once the bulbs have been confirmed, then check the multi-function switch.

 

[phatboy5015]

Once the bulbs have been confirmed, then check the multi-function switch.

What would that have to do with anything? If the third brake light works, then all the switches/relays are working. It's either bulbs or the harnesses behind the taillights.

 

[wmburns]

What would that have to do with anything? If the third brake light works, then all the switches/relays are working. It's either bulbs or the harnesses behind the taillights.

Not true.

The power for the 3rd brake light goes directly from the brake switch to the 3rd brake light. So you are correct that a working 3rd brake light "proves" the fuse and the brake switch.

However, the power for the brake lights themselves goes through the multi-function switch. The multi-function switch is needed to make the hazard lights blink and to control when the brakes are applied and the turn signal is on.

The wiring diagrams are very clear about that.

 

[phatboy5015]

Not true.

The power for the 3rd brake light goes directly from the brake switch to the 3rd brake light. So you are correct that a working 3rd brake light "proves" the fuse and the brake switch.

However, the power for the brake lights themselves goes through the multi-function switch. The multi-function switch is needed to make the hazard lights blink and to control when the brakes are applied and the turn signal is on.

The wiring diagrams are very clear about that.

Ahh.. I stand corrected.. I didn't think about that.

 

[gt_orange]

thanks guys, I will be buying a multi-function switch in the morning, the third brake light threw me for a loop. if its getting its power from different locations then that narrows it down. it hit 100000 2 months ago and nothing but problems since, I have rebuild the bottom end, the traction lock, and driving home from shooting fireworks I lost all gears. I had to stop and shut the car off then was able to get into 2nd to make it the last mile.

 

[wmburns]

Before you buy a multi-function switch, try activating the hazard lights multiple times. Sometimes using the switch will "clean" the contacts and restore function.

Note, the multi-function switch can be rebuilt. If you decide to tackle, take tons of pictures. Once the switch is apart, clean the switch contacts. Very lightly sand and re-grease the terminals with electrical di-electric grease.

 

[gt_orange]

I will, i rebuild the driver window motor last week, works good as new. I should post pics of that to

 

[gt_orange]

View attachment 72524
Found the problem, 2 of the wires backed out, easy fix