I’ll start with 68 XR7. I replaced the switch nearly 20 years ago and everything has been fine. Recently I started tracking down a hot wire smell then realized it was when I had my foot on the brake. Today I found the burned connector on the switch.
At first it looked like there was missing insulation on the wires so I assumed they had crossed, causing the issue. Now that I have a better look at it I believe the insulation probably melted because of another issue.
I’m hoping someone can steer me to what might have been the most likely cause. I have a new switch here but I’m reluctant to disconnect the old one. 20 years ago I was much more agile, today, even with the seat out I can barely get at that switch. Should I consider temporarily connecting it to the new switch before trying to install it?
Vic Yarberry has reproduced that wire harness because it is often burned up like that. The cause is using a wrong brake light switch. The reproduction switches are also made backwards which makes them harder to install and more likely to short out. This photo shows an NOS Ford switch on the left and the currently available Scott Drake part on the right.
Thanks Royce. Now that you mentioned it I have a vague memory from 20 years ago about the connector being on the wrong side. So if I’m understanding you correctly I shouldn’t use the Scott Drake switch, or any others with the connector on that side?
They can be used but are difficult to install. You may find that the connector needs to be insulated further, maybe a piece of tape over the terminals? Definitely you will need to pull the driver seat for access.
Common problem on Cougars and Shelby Mustangs.
It is probably due to the high brake current on these cars (>12A)
and the fact that the wire is flexed everytime the pedal is pushed.
My 67 switch burnt up, mostly. Luckily the female connector from the car harness wasn’t that bad.
I bought a new switch from Napa a couple months back and it looks like that Scott drake switch. Change it today in 10 minutes.
Where it went bad was on the switch, at the rivet, that connects the male blade to the switch. It heated up so much it burned the male blade off the switch and it was stuck in the female harness connector.
Maybe it’s time to go LED taillight bulbs, idk….
I’ve had to put that repair off for a few weeks but I think you have convinced me I do need to pull the switch so I can get a better look at it. It looked good from what I could see. The only visible damage was the connector. I was hoping that replacing just the connector will solve the problem but I think I’m being too optimistic.
Roy, WCCC had the answer. If you look at their description for the brake switch it shows order of assembly, which helped me figure out you can take the pin and one bushing to remove it. The other two bushings stay in place.
I couldn’t get both hands and head under there. Just enough to get one hand for me.
Wanted to mention that the side that went bad for me was green/wht. There is a copper colored metal strip inside the switch that is physically attached to the green/wht male blade side. To complete the circuit the other side of this strip makes contact with the other male blade (green/red side), when the brake pedal is pressed.
Side note: a couple years back I put up a picture of my brake connector with a little meltage on the grn/red side in which I removed the spade connector and squeezed it to close the gap a little. The male blades on the new brake switch are visibly thicker so the connector now fits much better.
Thanks for all the good info, I feel much more prepared to try to get back in there and pull that switch. It will be another couple weeks before I can get to it but I’m going to get to it this time.
With help from this forum I’m happy to report that even a fat old man can eventually get the old switch out and a new one in. What was nearly as amazing as the contortionist moves I made was the fact that the new switch seems to work great. It’s taking very little pedal pressure compared to the one I replaced.
The old switch doesn’t show any signs of damage or burned areas but I feel much better having a new one in there.
