Ok I took out brake light switch. S27 wrong thread size. So I have to find the correct thread size. Also no power going thru wires to switch. Also the rear taillight had two filament but rusted in. Any suggestions on rear taillight ideas. And is the wire going to switch supposed to have 12 volt constant? Thanks Jerry
yup. one of the wires should have 12 v all the time. if there is no power then maybe the switch is still ok
I agree, disconnect the wires, have a helper put pressure on the pedal, use a meter set on Ohms and the resistance (if good) should drop to close to zero.
So one wire has constant 12 volt? If not should the constant hot come from the headlights switch? Because it should be hot and then when brakes are applied both are hot.? Thanks Jerry
It can come from any hot source that is not keyed through the ignition switch. Should be able to press the brake pedal anytime and get brake lights.
I’m sorry I forgot to give back story on my car. It is a 1926 ford model t pick up. It has a Datsun 1600 cc motor and four speed. It was desired to 12 volt by friends dad. It sat for 25 years before I got it. I didn’t want them to crush it. On the light switch I had to replace it because it was old and rusted. So what I’m going to do is trace wires back to see where they go. And test for power. The brake switch might be good but like anything else when in doubt test test test. Thanks Jerry
Ok I started thinking and instead of just asking questions I thought let’s find the thread size first. So at my hardware store that has everything I found the pipe size for the brake switch is 1/8 pipe. The s27 I had thought wouldn’t work had a bunch of Teflon tape. The kragen guy said I could take off the tape. Guess what same threads. We tripled check. So I’m going to try it again. Also ford called for in mustang falcon etc. all the same standard s27. So I will try tomorrow. Thanks Jerry
Hi I found that this car has a fuse block. I cleaned up the connection and got a hot lead to the switch. My wife stood in the back while I pushed the brake pedal no brake lights. Also no power on both brake connectors as u push on the pedal. Scans e as you step on pedal both prong become energized? Also the master went dry due to leaking cap while I checked the thread size on switch. I am going to bleed the master cylinder . Then I’m going to bleed the brakes. I think the old switch is ok . Any ideas? Thanks Jerry
Make sure there's power to the switch. Disconnect the wire going to the back of the car, and see if it gets power to both terminals when you press the pedal. If the wiring in the back is shorted to ground, then you will see power go away when you press the brake pedal, like you are seeing (from what I understand, it's hard to be sure) Just take your time, get power to the switch, then out of the switch, then to the lights, then make the lights work. A test light is your friend, you can slowly work the power back to the lights, fixing problems as you go.
The fluid fitting thread should be neither 3/8", not 5/16". It should be 1/8" NPT (National Pipe Taper).
I'm glad you didn't let them crush it! That's a nice truck. After you work out the bugs, it will be a nice cruiser.
The Jalopy Journal
