The Ford Barn

zaugger · 09-09-2019, 03:41 PM

I was driving a 1929 Model A when the engine just stopped running. Put a new fuse to the starter, (it was blown) car started and started running again. For about 30 feet. Blew again. Now, even if I set a fuse on top of the connectors it explodes. Any thoughts? Thank you!

Tacoma Bob · 09-09-2019, 03:48 PM

Go down a couple of posts. Tom Endy has a great pdf in that post that will guide you.

zaugger · 09-09-2019, 04:35 PM

Thanks so much. I did exactly as the PDF said, and everything was fine until I added the light bail. Adding the light bail blew the fuse. When I disconnected the light bail and put in a new fuse it’s still blew. So I’m wondering if there’s an issue with the cutout or the generator itself? Any thoughts? Is there a way to test?

Tacoma Bob · 09-09-2019, 04:53 PM

Did you separate the bail? Like Tom mentioned it could be full of oil and shorting out in there.

zaugger · 09-09-2019, 05:12 PM

Yep. Separated it and cleaned it it. It did start for about 5 seconds after that before it blew. But then I disconnected the bail and a new fuse blew right when I put it in.

1931 flamingo · 09-09-2019, 05:36 PM

Sponsored Links (Register now to hide all advertisements)

Disconnect the wiring to the headlights and try the fuse again. FWIW
Paul in CT

zaugger · 09-09-2019, 05:43 PM

Ok. ItÂ’s magic. I reconnected everything and remembered it happened just after I was breaking. My friend who i am getting the car from mentioned he has replaced the brake switch several times. He looked underneath the car and the switch was open when it should have been closed. Disconnected the switch and bingo. Starts and stays lit. Any solutions the the continuing brake switch saga? Anyway, thanks SO MUCH for your help!

Bill G · 09-09-2019, 05:48 PM

The brake switch has power to it at all times that comes from the light switch bail. When you step on the brake, the power gets extended from the switch to the brake light in the tail light assembly. So, if it blows only when you step on the brake, then the output of the switch (the green wire that goes to the stop light is shorted somehow. It could be that the switch post itself is grounded, the green wire leading to the stop light could be frayed and grounded, or the stop light socket in the tail light assembly could be shorted to ground. Also, the switches themselves aren't foolproof. The short could be in the switch itself.

Mike V. Florida · 09-09-2019, 11:29 PM

Keep in mind that on the Model A the ignition switch only turns on the ignition, and only the power to the points at that. Everything else will have power when the battery is connected.

Tom Wesenberg · 09-10-2019, 02:43 AM

Most likely it has a bad repro brake switch that grounds out. Disconnect both brake switch wires then connect an ohm meter from each terminal to ground and try the switch both off and on to see if either terminal connects with ground. If it does then you can take it apart and correct the problem.

beefheart · 09-10-2019, 09:01 AM

mine was blowing because under the speedo amp fuel gauge housing a wire was just barely touching the rear of the tank area, also refreshed the fuse link on starter with a quality made one.

zaugger · 09-15-2019, 11:16 AM

Thanks, all. I may have some other issues, but for now I replaced the brake switch and no longer have the short.

1931 flamingo · 09-15-2019, 02:13 PM

Thanks for the update.
Paul in CT

100IH · 09-15-2019, 02:47 PM

Now take the switch apart and find the rest of the story. It is a simple thing, contacts and insulation to isolate a wire that is hot.

Troubleshooting is finding the location,cause and correction using a schematic and logic with simple tools like a test light. This is just the beginning, prepare for the future.

09-09-2019, 03:41 PM	#1
zaugger Member Join Date: Aug 2019 Location: Eden Prairie, MN Posts: 37	Fuse blows even when key off I was driving a 1929 Model A when the engine just stopped running. Put a new fuse to the starter, (it was blown) car started and started running again. For about 30 feet. Blew again. Now, even if I set a fuse on top of the connectors it explodes. Any thoughts? Thank you!

09-09-2019, 03:48 PM	#2
Tacoma Bob Senior Member Join Date: May 2010 Location: Tacoma, WA Posts: 1,025	Re: Fuse blows even when key off Go down a couple of posts. Tom Endy has a great pdf in that post that will guide you.

09-09-2019, 04:35 PM	#3
zaugger Member Join Date: Aug 2019 Location: Eden Prairie, MN Posts: 37	Re: Fuse blows even when key off Thanks so much. I did exactly as the PDF said, and everything was fine until I added the light bail. Adding the light bail blew the fuse. When I disconnected the light bail and put in a new fuse it’s still blew. So I’m wondering if there’s an issue with the cutout or the generator itself? Any thoughts? Is there a way to test?

09-09-2019, 04:53 PM	#4
Tacoma Bob Senior Member Join Date: May 2010 Location: Tacoma, WA Posts: 1,025	Re: Fuse blows even when key off Did you separate the bail? Like Tom mentioned it could be full of oil and shorting out in there.

09-09-2019, 05:12 PM	#5
zaugger Member Join Date: Aug 2019 Location: Eden Prairie, MN Posts: 37	Re: Fuse blows even when key off Yep. Separated it and cleaned it it. It did start for about 5 seconds after that before it blew. But then I disconnected the bail and a new fuse blew right when I put it in.

09-09-2019, 05:36 PM	#6
1931 flamingo Senior Member Join Date: May 2010 Location: new britain,ct 06052 Posts: 9,390	Re: Fuse blows even when key off Sponsored Links (Register now to hide all advertisements) Disconnect the wiring to the headlights and try the fuse again. FWIW Paul in CT

09-09-2019, 05:43 PM	#7
zaugger Member Join Date: Aug 2019 Location: Eden Prairie, MN Posts: 37	Re: Fuse blows even when key off Ok. ItÂ’s magic. I reconnected everything and remembered it happened just after I was breaking. My friend who i am getting the car from mentioned he has replaced the brake switch several times. He looked underneath the car and the switch was open when it should have been closed. Disconnected the switch and bingo. Starts and stays lit. Any solutions the the continuing brake switch saga? Anyway, thanks SO MUCH for your help!

09-09-2019, 05:48 PM	#8
Bill G Senior Member Join Date: Jun 2017 Location: Walla Walla, WA Posts: 1,045	Re: Fuse blows even when key off The brake switch has power to it at all times that comes from the light switch bail. When you step on the brake, the power gets extended from the switch to the brake light in the tail light assembly. So, if it blows only when you step on the brake, then the output of the switch (the green wire that goes to the stop light is shorted somehow. It could be that the switch post itself is grounded, the green wire leading to the stop light could be frayed and grounded, or the stop light socket in the tail light assembly could be shorted to ground. Also, the switches themselves aren't foolproof. The short could be in the switch itself.

09-09-2019, 11:29 PM	#9
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Fuse blows even when key off Keep in mind that on the Model A the ignition switch only turns on the ignition, and only the power to the points at that. Everything else will have power when the battery is connected. __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

09-10-2019, 02:43 AM	#10
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Fuse blows even when key off Most likely it has a bad repro brake switch that grounds out. Disconnect both brake switch wires then connect an ohm meter from each terminal to ground and try the switch both off and on to see if either terminal connects with ground. If it does then you can take it apart and correct the problem.

09-10-2019, 09:01 AM	#11
beefheart Member Join Date: Aug 2018 Posts: 34	Re: Fuse blows even when key off mine was blowing because under the speedo amp fuel gauge housing a wire was just barely touching the rear of the tank area, also refreshed the fuse link on starter with a quality made one.

09-15-2019, 11:16 AM	#12
zaugger Member Join Date: Aug 2019 Location: Eden Prairie, MN Posts: 37	Re: Fuse blows even when key off Thanks, all. I may have some other issues, but for now I replaced the brake switch and no longer have the short.

09-15-2019, 02:13 PM	#13
1931 flamingo Senior Member Join Date: May 2010 Location: new britain,ct 06052 Posts: 9,390	Re: Fuse blows even when key off Thanks for the update. Paul in CT

09-15-2019, 02:47 PM	#14
100IH Senior Member Join Date: Dec 2011 Location: SW Idaho Posts: 970	Re: Fuse blows even when key off Now take the switch apart and find the rest of the story. It is a simple thing, contacts and insulation to isolate a wire that is hot. Troubleshooting is finding the location,cause and correction using a schematic and logic with simple tools like a test light. This is just the beginning, prepare for the future.