Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 06-05-2012, 10:13 PM   #1
Des
Junior Member
 
Join Date: May 2012
Location: Australia
Posts: 2
Default points burning out on the Model A distributer

How do I stop contact points burning out on the Model A distributer?
Des is offline   Reply With Quote
Old 06-05-2012, 11:58 PM   #2
Peter J
Senior Member
 
Peter J's Avatar
 
Join Date: Jul 2010
Location: Olympia, WA
Posts: 691
Default Re: points burning out on the Model A distributer

Des,
Swap out your condenser, that could be it.
Pete
Peter J is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-06-2012, 02:38 AM   #3
dave in australia
Senior Member
 
Join Date: May 2010
Location: Victoria, Australia
Posts: 1,170
Default Re: points burning out on the Model A distributer

Do you have the right coil. Some coils require a ballast resistor to prevent the points from frying, that is if you have gone away from an original six volt coil.
dave in australia is offline   Reply With Quote
Old 06-06-2012, 02:40 AM   #4
pooch
Senior Member
 
pooch's Avatar
 
Join Date: Sep 2010
Location: South Coast NSW Australia
Posts: 2,596
Default Re: points burning out on the Model A distributer

My points were burning blue within minutes.

Turned out to be the powerhouse overcharging.
pooch is offline   Reply With Quote
Old 06-06-2012, 02:24 PM   #5
PetesPonies
Senior Member
 
PetesPonies's Avatar
 
Join Date: Jul 2011
Location: South Carolina
Posts: 314
Default Re: points burning out on the Model A distributer

Without a condenser operating properly, points will not last but a few minutes.
__________________
Pete's Ponies
Mustang RUSToration & Performance
PetesPonies is offline   Reply With Quote
Old 06-06-2012, 03:31 PM   #6
Mike V. Florida
Senior Member
 
Mike V. Florida's Avatar
 
Join Date: May 2010
Location: South Florida
Posts: 14,054
Send a message via AIM to Mike V. Florida
Default Re: points burning out on the Model A distributer

Sponsored Links (Register now to hide all advertisements)
ditto condensor
__________________
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
Mike V. Florida is offline   Reply With Quote
Old 06-06-2012, 06:44 PM   #7
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 8,099
Default Re: points burning out on the Model A distributer

A bad or loose connection at the battery cable will cause a voltage spike and burn out the points , I've had it happen .
Purdy Swoft is offline   Reply With Quote
Old 09-16-2019, 06:06 AM   #8
JRN1967
Senior Member
 
JRN1967's Avatar
 
Join Date: Sep 2017
Location: Monson, MA
Posts: 166
Default Re: points burning out on the Model A distributer

My points are lasting a coupe hundred miles, before they burn out. B distributor with a 6V system charging at 7 amps, I run parking lights while driving. I have 1.5 ohm resistor on incoming side.

Since I added the resistor it takes longer for the points to burn out. I also burn out brake lights unexpectedly.

I have checked all the connections from the starter through the ignition switch and amp meter to the distributor. I haven't checked the positive ground from the frame to the battery yet. But if that was loose, why would it turn over?

I run the diode for my cutout.
JRN1967 is offline   Reply With Quote
Old 09-16-2019, 09:00 AM   #9
Corley
Senior Member
 
Join Date: Aug 2011
Location: Battle Ground WA
Posts: 293
Default Re: points burning out on the Model A distributer

The whole purpose of the condenser is to act as a buffer for the counter emf of the coil, and protect the points from arcing and burning. As the points open, the surge of current needs a place to go, and the condenser absorbs this charge. Therefore, the value of the condenser needs to match the coils output pretty close. If the condenser is weak, or if the coil is not correct, the life of the points is negatively affected.

Condensers do go bad a lot more often than coils, so start there .
__________________
Corley
-----------------
Subscribed to the KISS principle!
Corley is offline   Reply With Quote
Old 09-16-2019, 09:11 AM   #10
JRN1967
Senior Member
 
JRN1967's Avatar
 
Join Date: Sep 2017
Location: Monson, MA
Posts: 166
Default Re: points burning out on the Model A distributer

Quote:
Originally Posted by Corley View Post
The whole purpose of the condenser is to act as a buffer for the counter emf of the coil, and protect the points from arcing and burning. As the points open, the surge of current needs a place to go, and the condenser absorbs this charge. Therefore, the value of the condenser needs to match the coils output pretty close. If the condenser is weak, or if the coil is not correct, the life of the points is negatively affected.

Condensers do go bad a lot more often than coils, so start there .
Ok, I'll give that a shot.
JRN1967 is offline   Reply With Quote
Old 09-16-2019, 09:32 AM   #11
ryanheacox
Senior Member
 
ryanheacox's Avatar
 
Join Date: Apr 2013
Location: Northwest CT
Posts: 1,092
Default Re: points burning out on the Model A distributer

Burning out brake lights would make me think a poor battery connection causing the generator voltage to spike like Purdy said back in 2012.



Have you burned out any more bulbs since going through your wiring? I would definitely check out your battery ground.
ryanheacox is offline   Reply With Quote
Old 09-16-2019, 09:39 AM   #12
johnbuckley
Senior Member
 
johnbuckley's Avatar
 
Join Date: Jul 2010
Location: United Kingdom
Posts: 1,439
Default Re: points burning out on the Model A distributer

Quote:
Originally Posted by Des View Post
How do I stop contact points burning out on the Model A distributer?
how long do they last before they're pitted/burnt out? Some of the "modern" type points in particular are poor quality and seem to last only 2000 miles or so whatever.
johnbuckley is offline   Reply With Quote
Old 09-16-2019, 11:00 AM   #13
JRN1967
Senior Member
 
JRN1967's Avatar
 
Join Date: Sep 2017
Location: Monson, MA
Posts: 166
Default Re: points burning out on the Model A distributer

Quote:
Originally Posted by johnbuckley View Post
how long do they last before they're pitted/burnt out? Some of the "modern" type points in particular are poor quality and seem to last only 2000 miles or so whatever.
John, my points are lasting about 200 miles. I'm using NOS model B point sets.

I will try a condenser, and look at my ground connection as Ryan suggests.

The only reason I didn't consider the ground was because it starts easily. Wouldn't it turn over slow if I had a poor ground?
JRN1967 is offline   Reply With Quote
Old 09-16-2019, 11:51 AM   #14
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 8,099
Default Re: points burning out on the Model A distributer

Sometimes a slightly loose ground connection will make good enough connection to work , other times it may not .
Purdy Swoft is offline   Reply With Quote
Old 09-16-2019, 12:09 PM   #15
Patrick L.
Senior Member
 
Patrick L.'s Avatar
 
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
Default Re: points burning out on the Model A distributer

Not much info to work with.
6v or 12v ? If 12v then look at the coil, make sure its a 3ohm or has a ballast resistor.
There shouldn't be more than 8v to the points.

A loose connection can cause the generator 'runaway' and put out about 30v.

As the others said, good info.
Patrick L. is offline   Reply With Quote
Old 09-16-2019, 12:16 PM   #16
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 8,712
Default Re: points burning out on the Model A distributer

These threads get so confusing we people hijack 7 year old threads. Need to start a new thread.
Bob C is offline   Reply With Quote
Old 09-16-2019, 03:00 PM   #17
JRN1967
Senior Member
 
JRN1967's Avatar
 
Join Date: Sep 2017
Location: Monson, MA
Posts: 166
Default Re: points burning out on the Model A distributer

Quote:
Originally Posted by Bob C View Post
These threads get so confusing we people hijack 7 year old threads. Need to start a new thread.
Yes I see, I was trying to do the opposite and not create a new thread with the same subject.
JRN1967 is offline   Reply With Quote
Old 09-16-2019, 05:20 PM   #18
30 Closed Cab PU
Senior Member
 
Join Date: Aug 2018
Posts: 2,332
Default Re: points burning out on the Model A distributer

I like what you did, shows you have already taken the initiative and done some research.


Let us know what you find using all of the info in this thread, new and old info.
30 Closed Cab PU is offline   Reply With Quote
Old 09-17-2019, 06:41 AM   #19
Patrick L.
Senior Member
 
Patrick L.'s Avatar
 
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
Default Re: points burning out on the Model A distributer

Oopps, I missed the date.
Patrick L. is offline   Reply With Quote
Old 09-17-2019, 02:12 PM   #20
Bob Bidonde
Senior Member
 
Bob Bidonde's Avatar
 
Join Date: May 2010
Location: Long Island, NY
Posts: 3,432
Default Re: points burning out on the Model A distributer

My best guess is that the points and or condenser case do not have a low resistance ground path back to the battery. Resistance should be 5 Ohms or less. I use jumpers to get the ground path resistance to 2 Ohms or less.
Attached Images
File Type: jpg Ground Resistance Check.jpg (17.1 KB, 58 views)
__________________
Bob Bidonde
Bob Bidonde is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:03 PM.