The Ford Barn

Jbuddy791 · 12-22-2014, 08:19 PM

I am relatively new with working on a '29 Model A. When I hooked up the speedometer cable the car seems to stall after about 2 min driving. When I go under and remove the speedometer cable from the driveshaft connection it runs like a top. Any thoughts?

newshirt · 12-22-2014, 08:33 PM

If this is really true, maybe it's an electrical short.

Perhaps... the speedo cable completes a ground circuit to the instrument panel, which has a partial short to the ignition switch. The results is reduced voltage to the points and ultimately to the spark plugs. Just a wild guess.

Do you get a strong blue spark when holding the coil wire near a head nut?

dr.j · 12-22-2014, 08:36 PM

Now this will be one for the books; I can hardly wait to see how this is resolved.

Gunmetal blue2 · 12-22-2014, 09:35 PM

Do something a little different, disconnect the speedometer cable from speedometer. there may be a wire touching the cable and when you hook it to the torque tube it makes a short.

Tom Wesenberg · 12-22-2014, 11:18 PM

A repro ignition switch that has terminals hitting the gas tank. Messing with the cable moved things just enough for the switch to not touch the tank.

Hey, it either that or the cable is turning off the gas valve.

Mike V. Florida · 12-22-2014, 11:40 PM

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As Tom said, when the connection is loose under the car the cable is "pulled" straight. When the connector is placed on the gear, the cable is pushed up into the space behind dash and may short out the ign switch.

Farrell In Vancouver · 12-23-2014, 10:36 AM

Hmmmm. Just about long enough for the vacuum to release from the tank. Check the gas cap vent for a partial blockage. Just remove the cap and see how long it runs.

Jbuddy791 · 12-28-2014, 01:24 PM

Thanks all. I'm going to check the "short" issue with the wiring. I'll let you know if I resolve this.

12-22-2014, 08:19 PM	#1
Jbuddy791 Junior Member Join Date: Oct 2013 Location: Chardon, Ohio Posts: 10	Weird ? about speedometer cable. I am relatively new with working on a '29 Model A. When I hooked up the speedometer cable the car seems to stall after about 2 min driving. When I go under and remove the speedometer cable from the driveshaft connection it runs like a top. Any thoughts?

12-22-2014, 08:33 PM	#2
newshirt Senior Member Join Date: Jan 2011 Location: Colorado Springs Posts: 868	Re: Weird ? about speedometer cable. If this is really true, maybe it's an electrical short. Perhaps... the speedo cable completes a ground circuit to the instrument panel, which has a partial short to the ignition switch. The results is reduced voltage to the points and ultimately to the spark plugs. Just a wild guess. Do you get a strong blue spark when holding the coil wire near a head nut? __________________ Ray White Last edited by newshirt; 12-22-2014 at 08:49 PM.

12-22-2014, 08:36 PM	#3
dr.j Senior Member Join Date: May 2010 Location: Portland, ON, Canada Posts: 315	Re: Weird ? about speedometer cable. Now this will be one for the books; I can hardly wait to see how this is resolved. __________________ Dave A Jamieson Portland, ON Canada 1928 Tudor

12-22-2014, 09:35 PM	#4
Gunmetal blue2 Senior Member Join Date: Apr 2013 Location: Columbia, TN.38401 Posts: 422	Re: Weird ? about speedometer cable. Do something a little different, disconnect the speedometer cable from speedometer. there may be a wire touching the cable and when you hook it to the torque tube it makes a short.

12-22-2014, 11:18 PM	#5
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Weird ? about speedometer cable. A repro ignition switch that has terminals hitting the gas tank. Messing with the cable moved things just enough for the switch to not touch the tank. Hey, it either that or the cable is turning off the gas valve.

12-22-2014, 11:40 PM	#6
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Weird ? about speedometer cable. Sponsored Links (Register now to hide all advertisements) As Tom said, when the connection is loose under the car the cable is "pulled" straight. When the connector is placed on the gear, the cable is pushed up into the space behind dash and may short out the ign switch. __________________ 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

12-23-2014, 10:36 AM	#7
Farrell In Vancouver Senior Member Join Date: May 2010 Location: Pitt Meadows BC Posts: 1,003	Re: Weird ? about speedometer cable. Hmmmm. Just about long enough for the vacuum to release from the tank. Check the gas cap vent for a partial blockage. Just remove the cap and see how long it runs.

12-28-2014, 01:24 PM	#8
Jbuddy791 Junior Member Join Date: Oct 2013 Location: Chardon, Ohio Posts: 10	Re: Weird ? about speedometer cable. Thanks all. I'm going to check the "short" issue with the wiring. I'll let you know if I resolve this.