Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 08-23-2017, 01:33 PM   #1
Darrell Kinnan
Junior Member
 
Join Date: Jan 2012
Posts: 19
Default Ballast resistor.

Installed a new ballast resistor on a rough running 37 engine. Started the engine and the resistor started smoking. Put the original back on, it's made out of ceramics, it didn't smoke but reach to 300 degrees. Should the resistor run this hot, if not, what could be the problem? Obviously the new ballast resistors can't stand the heat as they are not ceramic.

Always grateful for your help,
Darrell
Darrell Kinnan is offline   Reply With Quote
Old 08-23-2017, 01:44 PM   #2
RalphM
Senior Member
 
RalphM's Avatar
 
Join Date: Nov 2015
Location: North Pole, Alaska
Posts: 2,512
Default Re: Ballast resistor.

They do get warm, not sure of the actual temp.
If this is ignition resistor, they still make ceramic ones. Do a search for part number. It has been discussed here before.
RalphM is online now   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 08-23-2017, 01:48 PM   #3
flatheadmurre
Senior Member
 
flatheadmurre's Avatar
 
Join Date: Apr 2015
Location: Sweden
Posts: 3,045
Default Re: Ballast resistor.

If the coil is drawing to much current....being partial shortened or some other issue the resistor will heat up more then it should.
They should heat up a fair bit...that´s part of the design.
Those chinese bambo versions from the company whos name we shall not mention are just plain junk...you´re better of fixing your old one...
flatheadmurre is offline   Reply With Quote
Old 08-23-2017, 01:57 PM   #4
George/Maine
Senior Member
 
George/Maine's Avatar
 
Join Date: May 2010
Location: Mid coast Maine
Posts: 1,878
Default Re: Ballast resistor.

The resister is about .5 ohms but you must have a watt rating of 10
See if you can get one on line .5ohms 10 watts

Last edited by George/Maine; 08-23-2017 at 05:43 PM.
George/Maine is offline   Reply With Quote
Old 08-24-2017, 01:39 AM   #5
BillM
Senior Member
 
BillM's Avatar
 
Join Date: May 2010
Location: Everett, WA
Posts: 504
Default Re: Ballast resistor.

HTML Code:
See if you can get one on line   .5ohms 10 watts
Ignition ballast resistors have a positive temperature coefficient; as they get hotter their resistance increases. Normal power resistors have a neutral temperature coefficient so don't react like ballast resistors. There was a post recently that listed different values of ballast resistors from NAPA I believe. That would be what one would want if you need a special resistance.
__________________
My web page:
http://myplace.frontier.com/~wgmumaw/
BillM is offline   Reply With Quote
Old 08-24-2017, 08:32 AM   #6
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 14,439
Default Re: Ballast resistor.

All of these are higher value than what you need for a stock Ford application.

•#ICR23 – 1.20 ohms
•#ICR11 – 1.35 ohms
•#ICR34 – 1.40 ohms
•#ICR37 – 1.60 ohms
•#ICR35 – 1.80 ohms
•#ICR13 – 1.82 ohms
Lucas* 3BR (1.3 - 1.4 Ohms)
Mopar* DCC-4529795 (1.40 Ohms)
Accel* ACC-150250 (1.35 Ohms)
Standard* RU-4 (1.35 Ohms)
Standard RU-23 (1.20 ohms)
Standard RU-37 (1.40 Ohms)
JSeery is offline   Reply With Quote
Old 08-24-2017, 08:54 AM   #7
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 11,687
Default Re: Ballast resistor.

We need to know if this is a stock 6-volt system. Resistors use some power to drop voltage and control current since they are a load device. They will get hot so they use ceramics & place them on a board that can take some heat. Ford generally placed the board in an area where they will be somewhat protected from hazards.
rotorwrench is offline   Reply With Quote
Old 08-24-2017, 10:17 AM   #8
George/Maine
Senior Member
 
George/Maine's Avatar
 
Join Date: May 2010
Location: Mid coast Maine
Posts: 1,878
Default Re: Ballast resistor.

I think the 6 volt coils need about 3 amps or 4.5 volts to work. With no special meters ,only a volt meter if you measure 1.5 volts across the resister that should be good. By putting a larger 1.5 ohms you cut the amps to 2 amps and the coil voltage to 3 volts. So with a .5 ohm 10 watt this should work if you can't find a original resister.
George/Maine is offline   Reply With Quote
Old 08-24-2017, 10:54 AM   #9
Init1
Senior Member
 
Init1's Avatar
 
Join Date: May 2010
Location: Oregon City, Oregon
Posts: 208
Default Re: Ballast resistor.

Be careful you use the right resistor. If you use one with too much resistance it will reduce the juice to the plugs and soot them up so much they will misfire.
If you see black sooty plugs your resistor is too big.
Init1 is offline   Reply With Quote
Old 08-24-2017, 04:29 PM   #10
G.M.
Senior Member
 
Join Date: May 2010
Location: Florida and Penna.
Posts: 4,356
Default Re: Ballast resistor.

Quote:
Originally Posted by Init1 View Post
Be careful you use the right resistor. If you use one with too much resistance it will reduce the juice to the plugs and soot them up so much they will misfire.
If you see black sooty plugs your resistor is too big.
This sounds like more of a guess than fact. Truth is the engine will
run good on 4 volts to the coil and also good in the 3.5+ range but
when you get below 3.5 it may not even start. In the lower range
sometimes it will start just as you release the starter the engine is
still spinning and the voltage to the coil increases from the voltage
increase when the starter disengages. Much over 4 volts will cause
the points to arc and pit them. G.M.
__________________
www.fordcollector.com
G.M. is offline   Reply With Quote
Old 08-24-2017, 05:39 PM   #11
Darrell Kinnan
Junior Member
 
Join Date: Jan 2012
Posts: 19
Default Re: Ballast resistor.

Here's what I'm getting with the engine not running:

6 volts on the battery
2 volts at the coil
6 volts on the ignition side of the resistor
2.5 volts on the coil side of the resistor

Is the resistor taking too much from the coil? Engine starts but runs real rough.

Darrell
Darrell Kinnan is offline   Reply With Quote
Old 08-24-2017, 06:13 PM   #12
Init1
Senior Member
 
Init1's Avatar
 
Join Date: May 2010
Location: Oregon City, Oregon
Posts: 208
Default Re: Ballast resistor.

Just like I said......
Init1 is offline   Reply With Quote
Old 08-24-2017, 06:43 PM   #13
George/Maine
Senior Member
 
George/Maine's Avatar
 
Join Date: May 2010
Location: Mid coast Maine
Posts: 1,878
Default Re: Ballast resistor.

Quote:
Originally Posted by Darrell Kinnan View Post
Here's what I'm getting with the engine not running:

6 volts on the battery
2 volts at the coil
6 volts on the ignition side of the resistor
2.5 volts on the coil side of the resistor

Is the resistor taking too much from the coil? Engine starts but runs real rough.

Darrell
I like to test when running, measure across resister.
I would buy a resister from
Resistor Fuse Terminal Block
1933 - 37
40-12250
dennis-carpenter
about $30 looks like original.
George/Maine is offline   Reply With Quote
Old 08-24-2017, 08:05 PM   #14
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 14,439
Default Re: Ballast resistor.

Quote:
Originally Posted by Darrell Kinnan View Post
Here's what I'm getting with the engine not running:

6 volts on the battery
2 volts at the coil
6 volts on the ignition side of the resistor
2.5 volts on the coil side of the resistor

Is the resistor taking too much from the coil? Engine starts but runs real rough.

Darrell
Several issues here, but the big one appears to be the voltage drop across the ballast resistor. The coil needs a min of 3.5v (as already stated) and is better at around 4.0v. The battery should be greater than 6v not running, more in the 6.2-6.3 range and somewhere above 7v running.
JSeery is offline   Reply With Quote
Old 08-24-2017, 08:40 PM   #15
BillM
Senior Member
 
BillM's Avatar
 
Join Date: May 2010
Location: Everett, WA
Posts: 504
Default Re: Ballast resistor.

Quote:
If the coil is drawing to much current....being partial shortened or some other issue the resistor will heat up more then it should.
Agree with flatheadmurre.
__________________
My web page:
http://myplace.frontier.com/~wgmumaw/
BillM is offline   Reply With Quote
Old 08-24-2017, 08:46 PM   #16
JSeery
Senior Member
 
JSeery's Avatar
 
Join Date: Nov 2012
Location: Wichita KS
Posts: 14,439
Default Re: Ballast resistor.

Quote:
Originally Posted by BillM View Post
Agree with flatheadmurre.
Don't think so with these voltage numbers.
JSeery is offline   Reply With Quote
Old 08-24-2017, 11:37 PM   #17
flatheadmurre
Senior Member
 
flatheadmurre's Avatar
 
Join Date: Apr 2015
Location: Sweden
Posts: 3,045
Default Re: Ballast resistor.

If the coil is shorted out having a lower resistance then it should have you get readings like this.
Or if the ballast resistor has a bad connection between the resistance wire and the connection points giving it a higher value then it should have.
Is the coil heating up more then normal ?
flatheadmurre is offline   Reply With Quote
Old 08-27-2017, 02:57 PM   #18
Darrell Kinnan
Junior Member
 
Join Date: Jan 2012
Posts: 19
Default Re: Ballast resistor.

Thanks for all replies. I've learn that ballast resistors can get red hot. I put the old one back on and it seems to be working ok with at least 2.5 volts to the coil. Waiting for Skip to rebuild the coil and have received a distributor rebuild back from Cliff Green. Hope to be on the road soon. DK
Darrell Kinnan is offline   Reply With Quote
Old 08-27-2017, 03:59 PM   #19
Paul Bennett
Senior Member
 
Join Date: Sep 2016
Posts: 605
Default Re: Ballast resistor.

My 1950 car havingh no resistor I'm want to ask, what year did resistors no longer become standard on Ford engines?
Paul Bennett is offline   Reply With Quote
Old 08-27-2017, 04:39 PM   #20
TJ
Senior Member
 
TJ's Avatar
 
Join Date: May 2010
Location: Napa,California
Posts: 4,536
Default Re: Ballast resistor.

I think your '50 went to the coil with the internal resistor.
TJ 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 12:51 AM.