Newbie having wireing problems any help?

DeBordEngineMan

DeBordEngineMan

Senior Member
As stated I am a newbie on the model A, I have been trying to get my 29 Tudor sedan on the road and have some fun!!!! Problem is I put all new wiring harness on hooked up everything car runs fine everything works that way headlights burn and work good, horn blows but every time I hook up my break light switch(new switch) and mount it on transmission everything go's dead what am I doing wrong? looked at all wiring no bad spots everything looks good. But can't figure it out any suggestions? Thanks for any help Robert DeBord .
 
sounds like you may have a bad switch. Take your ohm meter and see if it goes to ground. Sounds like it is shorted to ground. If it is it should work properly if you dont let it touch a ground for example hold it in you hand and it should work the lights and brake light.
 
Sounds like an internal short in the switch. Have you installed the switch with out the wire going to the tail light? I know others will chime in with more thoughts. Good luck and happy motoring!
 
Mine is not mounted on the transmission?
it is just behind the the cross frame ,Just at the end of the rod that is connected to the break pedal:)
 
assuming that your not applying your brake lite sounds like it could be a defective switch. if it does it applying your brake lite possible wiring problem from switch to rear of vehicle or even the wrong bulb installed.
 
I agree that most likely you have a bad switch. Connect an ohm meter from ground to each of the terminals. There should be NO continuity, then pull the switch on and there still should be no continuity to ground from either terminal, but the two terminals should have continuity to each other. Best to test the switch as soon as you buy it because I have heard of this shorting to ground problem a couple of times.

Also on the 28 and 29 switches, which are mounted to the ******, if the brake pedal goes too far towards the floor it may pull the switch rod past the end of the case. The 30 and 31 don't have this problem of pulling the rod too far because they operate by having a spring inside the switch push the contacts on when the brake pedal is applied.

In other words the early switch is off until pulled on, and the late switch is on until pushed off.
 
All of the switches I have purchased and installed, the instructions that came with them said to test them and to not over extend the rod that passes through the housing or it will cause a short.
 
Thanks guys for all the answers I can mount the two wires on the switch and hold it in my hand and everything still works except taillight but soon as I touch it to any metal everything go's out have not tried to hold and see if switch works brake light, I too thought that it may be a bad switch but I have not tested it yet, sometimes it is better for me to just stop and think about it for a little bit and ask for help hear on fordbarn thanks for all the help guys will test more tomorrow and post new findings. Robert DeBord
 
DeBordEngineMan said:
Thanks guys for all the answers I can mount the two wires on the switch and hold it in my hand and everything still works except taillight but soon as I touch it to any metal everything go's out have not tried to hold and see if switch works brake light, I too thought that it may be a bad switch but I have not tested it yet, sometimes it is better for me to just stop and think about it for a little bit and ask for help hear on fordbarn thanks for all the help guys will test more tomorrow and post new findings. Robert DeBord
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Hey Robert be sure you have the wires to the brake light (green and green) not the tail light then just touch the two brakelight wires together and hold them the brake light should burn. This should have no effect on the tail light if it does check for light ground and try running a tempory ground like a jumper wire to the light housing and see if that fixes it
 
BrakeSw-2.jpg

BrakeSw-1.jpg

BrakeSw.jpg


Here's what an original brake switch for 1928-9 looks like on the inside. I don't know how the repro looks on the inside. BTW, the red grease is Mystik JT-6 high temp. The tube of dielectric is what I used just on the contacts. It's a clear grease and doesn't show in this picture. If you look closely at the bottom picture you can see the spring is broken and that's why this original switch didn't turn off. The fix was easy, but saving the 4 cover tabs is the hard part.
 
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Hey Tom thanks for posting pictures I tried the switch today, with the light switch in the parking light only position, green brake wires unhooked from the switch not touching each other only parking lights on headlight and rear come on then I could touch the two green brake wires together and the brake light would come on then when you hook both green brake wires up to the brake switch and hold it in my hand the light would stay on and would not go off and I worked the plunger back and forth with no change so I guess that tells me that I have a bad switch right? Also one of my headlights is real dim and the other is bright I changed bulbs from one to the other it was not the bulb looked at everything could not see anything out of place any suggestions on this new problem? So I guess a new brake switch is in order on the other problem this one came from Mike's Afordable who would have a better quality switch? Any suggestions? I am going to take the one I have apart to see what is going on with it first maybe a easy fix? Well thanks for all the help guys posted late tonight I put my top on today took longer than I thought turned out pretty good for my first time putting one on, going to put gutter rails on tomorrow.I hope???? thanks again Robert DeBord
 
Your headlight problem is probably a bad ground. clean the socket in the headlight bar to bare metal. You may also need to clean where the bar mounts to the fender brace and where the brace bolts to the frame. Or you could run a ground wire.
 
"Also one of my headlights is real dim and the other is bright I changed bulbs from one to the other it was not the bulb looked at everything could not see anything out of place any suggestions on this new problem? "

To check for a bad ground just take a wire and touch the headlight bucket and a head nut or any good ground. If the headlight gets brighter then a bad ground is indicated.

Can you post or email me a picture of the inside of the bad switch as soon as the cover is removed? I'd like to see what goes wrong on the repro switches. tjw2831@hotmail.com Thanks
 
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Get a different switch. Some of the repro switches are junk. I had one that was made incorrectly, and when I pushed the brake pedal, it went past where it should have internally,and shorted out. I compared it to an original, and it was not made to have as much travel as the original. I rebuilt an original, and now have no problem
 
Hey Tom I will post a picture or email a picture to you as soon as I can today or tomorrow of the inside of the switch thanks for the help from everybody. Thanks Robert DeBord
 
Hey Tom here are the pictures of the new reproduction brake light switch inside also check your email. Robert DeBord
 

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Where did that switch come from? The way it is now the contacts are touching when they should not, and they are not touching when they should. You can bend the contacts so they look like the ones on my original switch. The upper contact should curl under the lower contact and spring up to make contact when the switch rod is pulled about 1/4".
 
In addition to the contact issue, there would also appear to be a short between at least one contact and ground, as TK in LA said in the second response.

Do you have an ohmmeter that you can use to check for continuity between the contacts and the body of the switch? There should be NO continuity from the body to either contact.

Joe
 
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