The Ford Barn

blaneys98 · 05-26-2018, 02:21 PM

Was working on my 30 roadster today putting on a dual updraft manifold and carbs. I started it multiple times as I the was adjusting the Idle and the battery was running low. While starting, It began to smoke from the dash and the wires started a small fire. I pulled the dash and the amp meter wires were burning. (It has a stock 6volt system). I pulled the amp meter and its wires. I ran a 10 AWG jumper instead of amp meter wiring. Hooked everything back up and it immediately burned the wiring harness to the generator. Any ideas on what is causing this?

I have had the car 2 years without any electrical problems. I know IÂ’ll need to replace these harnesses, but I want to figure out the problem before I ruin another harness.

J Franklin · 05-26-2018, 04:43 PM

It is a short to ground, check things with an ohmmeter.

Gary in La. · 05-26-2018, 07:38 PM

Bad cut out.

Chuck Sea/Tac · 05-26-2018, 08:41 PM

Did it start smoking the second time with the key on or off? I’m assuming you disconnected the battery to jumper the amp meter? Then reconnected.

Purdy Swoft · 05-26-2018, 08:45 PM

I agree with Gary .The points in the cut out are probably stuck . The cut out problem had probably caused the generator to try and motor . The generator would get pretty hot and weaken the battery. Overloading the system caused more heat and wires started to burn . If the cutut is really bad , it can be gutted and a diode can be added to replace the troublesome cut out points . Bratton lists a diode conversion kit for six dollars and ninety five cents on page 73 of their catalog . A better but more expensive replacement for the cfut out is the Fun Projects can style voltage regulator .I have used both with excellent results .

Bill G · 05-26-2018, 08:59 PM

Sponsored Links (Register now to hide all advertisements)

Time to add a fuse?

blaneys98 · 05-26-2018, 09:13 PM

Thanks for the responses. It burned with the key off almost instantaneously after I added the jumper and reconnected the battery. I just pulled the cutout cover and the points are not stuck shut. I have had intermittent problems with the brake switch. Could this be the cause?

I bought the starter fuse last week and obviously didn’t get it installed quick enough. Just glad it happened when I was there or the car and my house would have went up in flames. I’ve never seen wires burn like that. They were completely burned.

Tom Wesenberg · 05-27-2018, 12:44 AM

Yes, my money is on the brake switch being shorted to ground.
Take it apart and fix it, or buy a quality switch from A&L.

Bob C · 05-27-2018, 11:38 AM

NOS switch for good price. https://www.ebay.com/itm/NOS-Model-A....c100290.m3507

Bob

CarlG · 05-27-2018, 10:30 PM

FWIW, As a young lad of 15, I burned up not one but two wiring harnesses in my first ever vehicle, an AA. (Didn't learn my lesson the first time) Bought the replacement harness at JC Whitney (about $5), the NOS Amp gauge (still in the Ford box) from our local "wrecking yard" (25¢).

chap52 · 05-28-2018, 07:05 AM

Glad you were there to get it under control before it spread. There is ALWAYS a blessing hidden in these adventures. You have already acknowledged one here. Chap

eagle · 05-28-2018, 08:56 AM

You DEFINITELY need to install the fuse or a breaker. There are just no good reasons not to do it. As Tom says, carefully take your stop light switch apart and repair it. Too many of the repros are no good/poor Q.

oldman - NorCal · 05-28-2018, 01:12 PM

My short was at the horn. Thankfully, there was no fire as the car was parked in the attached garage. Replaced all my wiring and have had a fuse ever since. I too, had my car for over 20 years at the time without any problems.

blaneys98 · 05-28-2018, 09:21 PM

It was the brake light switch. Odd that it burned the amp gage wires first but they appear to be the smallest gauge.

chap52 · 05-29-2018, 09:04 AM

I knew you would track it down. Good job, Chap

Chuck Sea/Tac · 05-30-2018, 04:33 PM

Good job!

jm29henry · 05-31-2018, 08:50 AM

Great news a real learning experience for me thanks

Y-Blockhead · 05-31-2018, 12:36 PM

Good to see you found the problem. I hope you have installed your fuse along with a Master Cutoff Switch on the Battery Ground Cable.

Now the hard part is getting the replacement smoke back in the wires...

katy · 06-01-2018, 08:53 AM

Quote:

Now the hard part is getting the replacement smoke back in the wires...

The easiest way is to take the band off of the generator and pour the smoke into the generator when the engine is running at a fast idle.

05-26-2018, 02:21 PM	#1
blaneys98 Junior Member Join Date: Jun 2016 Location: Washington Township, NJ Posts: 11	Burning wiring harness Was working on my 30 roadster today putting on a dual updraft manifold and carbs. I started it multiple times as I the was adjusting the Idle and the battery was running low. While starting, It began to smoke from the dash and the wires started a small fire. I pulled the dash and the amp meter wires were burning. (It has a stock 6volt system). I pulled the amp meter and its wires. I ran a 10 AWG jumper instead of amp meter wiring. Hooked everything back up and it immediately burned the wiring harness to the generator. Any ideas on what is causing this? I have had the car 2 years without any electrical problems. I know IÂ’ll need to replace these harnesses, but I want to figure out the problem before I ruin another harness.

05-26-2018, 04:43 PM	#2
J Franklin Senior Member Join Date: May 2010 Location: Oregon Posts: 5,963	Re: Burning wiring harness It is a short to ground, check things with an ohmmeter.

05-26-2018, 07:38 PM	#3
Gary in La. Senior Member Join Date: May 2010 Location: Louisiana Posts: 866	Re: Burning wiring harness Bad cut out.

05-26-2018, 08:41 PM	#4
Chuck Sea/Tac Senior Member Join Date: May 2010 Location: Between Seattle & Tacoma Posts: 2,354	Re: Burning wiring harness Did it start smoking the second time with the key on or off? I’m assuming you disconnected the battery to jumper the amp meter? Then reconnected.

05-26-2018, 08:45 PM	#5
Purdy Swoft Senior Member Join Date: May 2010 Location: Alabama Posts: 8,099	Re: Burning wiring harness I agree with Gary .The points in the cut out are probably stuck . The cut out problem had probably caused the generator to try and motor . The generator would get pretty hot and weaken the battery. Overloading the system caused more heat and wires started to burn . If the cutut is really bad , it can be gutted and a diode can be added to replace the troublesome cut out points . Bratton lists a diode conversion kit for six dollars and ninety five cents on page 73 of their catalog . A better but more expensive replacement for the cfut out is the Fun Projects can style voltage regulator .I have used both with excellent results .

05-26-2018, 08:59 PM	#6
Bill G Senior Member Join Date: Jun 2017 Location: Walla Walla, WA Posts: 1,045	Re: Burning wiring harness Sponsored Links (Register now to hide all advertisements) Time to add a fuse?

05-26-2018, 09:13 PM	#7
blaneys98 Junior Member Join Date: Jun 2016 Location: Washington Township, NJ Posts: 11	Re: Burning wiring harness Thanks for the responses. It burned with the key off almost instantaneously after I added the jumper and reconnected the battery. I just pulled the cutout cover and the points are not stuck shut. I have had intermittent problems with the brake switch. Could this be the cause? I bought the starter fuse last week and obviously didn’t get it installed quick enough. Just glad it happened when I was there or the car and my house would have went up in flames. I’ve never seen wires burn like that. They were completely burned.

05-27-2018, 12:44 AM	#8
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Burning wiring harness Yes, my money is on the brake switch being shorted to ground. Take it apart and fix it, or buy a quality switch from A&L.

05-27-2018, 11:38 AM	#9
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,754	Re: Burning wiring harness NOS switch for good price. https://www.ebay.com/itm/NOS-Model-A....c100290.m3507 Bob

05-27-2018, 10:30 PM	#10
CarlG Senior Member Join Date: Nov 2010 Location: Anchorage, Alaska Posts: 9,115	Re: Burning wiring harness FWIW, As a young lad of 15, I burned up not one but two wiring harnesses in my first ever vehicle, an AA. (Didn't learn my lesson the first time) Bought the replacement harness at JC Whitney (about $5), the NOS Amp gauge (still in the Ford box) from our local "wrecking yard" (25¢). __________________ Alaskan A's Antique Auto Mushers of Alaska Model A Ford Club of America Model A Restorers Club Antique Automobile Club of America Mullins Owner's Club

05-28-2018, 07:05 AM	#11
chap52 Senior Member Join Date: Jun 2013 Location: Marana Arizona Posts: 1,776	Re: Burning wiring harness Glad you were there to get it under control before it spread. There is ALWAYS a blessing hidden in these adventures. You have already acknowledged one here. Chap

05-28-2018, 08:56 AM	#12
eagle Senior Member Join Date: Aug 2011 Location: Eagle Bend, MN Posts: 2,025	Re: Burning wiring harness You DEFINITELY need to install the fuse or a breaker. There are just no good reasons not to do it. As Tom says, carefully take your stop light switch apart and repair it. Too many of the repros are no good/poor Q. __________________ "There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."

05-28-2018, 01:12 PM	#13
oldman - NorCal Member Join Date: May 2010 Location: Gold Country Posts: 64	Re: Burning wiring harness My short was at the horn. Thankfully, there was no fire as the car was parked in the attached garage. Replaced all my wiring and have had a fuse ever since. I too, had my car for over 20 years at the time without any problems.

05-28-2018, 09:21 PM	#14
blaneys98 Junior Member Join Date: Jun 2016 Location: Washington Township, NJ Posts: 11	Re: Burning wiring harness It was the brake light switch. Odd that it burned the amp gage wires first but they appear to be the smallest gauge.

05-29-2018, 09:04 AM	#15
chap52 Senior Member Join Date: Jun 2013 Location: Marana Arizona Posts: 1,776	Re: Burning wiring harness I knew you would track it down. Good job, Chap

05-30-2018, 04:33 PM	#16
Chuck Sea/Tac Senior Member Join Date: May 2010 Location: Between Seattle & Tacoma Posts: 2,354	Re: Burning wiring harness Good job!

05-31-2018, 08:50 AM	#17
jm29henry Senior Member Join Date: Sep 2010 Location: michigan Posts: 1,126	Re: Burning wiring harness Great news a real learning experience for me thanks

05-31-2018, 12:36 PM	#18
Y-Blockhead Senior Member Join Date: Jul 2011 Location: Redondo Beach, CA Posts: 5,849	Re: Burning wiring harness Good to see you found the problem. I hope you have installed your fuse along with a Master Cutoff Switch on the Battery Ground Cable. Now the hard part is getting the replacement smoke back in the wires... Last edited by Y-Blockhead; 05-31-2018 at 12:58 PM.