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started popping fuses... and I think I've narrowed it down to the brake switch.. radio by itself is fine and the blinkers by themselves are fine.. but the sec I hook up the two wires to the switch on the master cylinder it blows.. I've had them go bad but not blow a fuse. brake fluid is also pushing its way out through the switch.. could that cause the problem I've having ? I have check wiring all the way back and haven't found anything.....yet
If your brake light switch is leaking then you should replace it. They don't cost much so that could be an easy fix. Make sure your brake fluid is clean and fresh. Otherwise, the two wires connected to the switch should be closely examined for a potential short. The red wire (assuming it's original wiring) goes from the brake switch to the turn signal flasher, where it joins an orange/yellow wire which goes to the fuse panel. The red/black wire leaves the brake switch, goes through a firewall connector (which can be a source of trouble) and then into the turn signal switch. Good luck!
If your brake light switch is leaking then you should replace it. They don't cost much so that could be an easy fix. Make sure your brake fluid is clean and fresh. Otherwise, the two wires connected to the switch should be closely examined for a potential short. The red wire (assuming it's original wiring) goes from the brake switch to the turn signal flasher, where it joins an orange/yellow wire which goes to the fuse panel. The red/black wire leaves the brake switch, goes through a firewall connector (which can be a source of trouble) and then into the turn signal switch. Good luck!
X2
Fix the known bad parts (brake light switch) before doing any trouble shooting.
i think you have more than one problem. the switch just closes the connection. you should be able to close the connection by hand (jumper the two wires) and the brake lights should come on. if you touch them together and you blow a fuse you have a short somewhere.
I have chased similar problems with the pressure type brake light switches on mid 60's Fords. We spent a couple hours chasing the same problem when building my son's truck (avatar).
The insulator between the two switch contacts can crack. This crack can / will fill with whatever debris is floating around under the hood. This sludge, for lack of a better term, is usually conductive allowing current flow from the terminal(s) to the switch shell, which is grounded.
If the path to ground is from the "hot" terminal of the switch there will be a "short" whenever the ignition key is on (on Slicks) and if the path to ground is on the "switched" terminal the "short" will only appear when the ignition switch is on and the brake pedal is pushed.
Thanks for the answers and lesson also Carter, you guys were right, new brake switch and everything works, got one at the local NAPA for under ten... Love this truck!!
This switch is pressure activated by stepping on the brake pedal, it's notorious for getting gummed up with dirty brake fluid.
Hi guys
I've had similar issues on my 63 F100 - my brake lights stay on once I've been driving a short while. I think it is down to the switch leaking across the connector as it is gummed up good. I've ordered a few switches off RockAuto via Fed Ex as I'm in the UK, but the connector is old and split. Can't find any link to the actual connector to buy a replacement. Can anybody point me in the right direction?? Rock is great for getting stuff sent over here, but any supplier that ships will do or eBay.. thank you
My '62 never had a connector to the brake light switch since I've owned it. If you don't need it to be original for a show truck. Bullet style insulated female crimp on connectors will work just fine. Normally it slides over the pin firmly, but you may need to squeeze it just a tad and then slide it on the pin.
Thanks Tom, that a very valid point. I'm waiting for the Rock order of new switches and think I'll follow the suggestion. It's certainly not a show truck. More a weekend spirit lifter
Q: Reckon I could get away with pulling the switch without bleeding the brakes afterwards? Not sure if air'll get in there if I switch it out quickly.... I'll see how it goes I guess. She's the oldest motor I've owned and gotta say after using garages all my life, it's a big learning curve trying to do stuff myself. Really shoulda listened to the old man more!!!
You could "probably" just change the switch without bleeding the brakes. If you can get a helper. Have them ever so lightly press down the pedal so that it's just barely pushing fluid out from the hole for the switch and sorta hold it at that point while you are quickly changing the switch. I have done that in the past. Just put a rag under to try to catch the fluid.
In your spot, I did a broad internet search and found most people were good with the simple swap, and some were militant about bleeding afterwards.
I did the hot-swap a few months ago on my dual circuit, power assist, drum/drum system. My switch is on the rear drum circuit. Brakes feel solid, so it worked for me. But fronts are more critical than rears, and you have a single pot - so that adds a question mark.
I took a spin just before the swap, and then again right after the swap, and could not discern a difference.
In regular driving, I tend to downshift to engage the rears 100% - and chirp 'em to scare the landlubbers around me, when required.
Your switch is 'upside down' - so gravity may be working against you.
At least, I would take it for a spin just before the swap, and then again right after the swap, and try to decide if any air got in there.
BTW, pic below shows the dual, female, bullet style connectors as noted above.
09-09-2015, 02:14 PM
