[AT] IH B275 Diesel

Wed Dec 6 20:25:37 PST 2006

Kevin:

I would respectfully request that you re-read Brett's initial response on
this thread. Assuming a serial circuit setup and 12 Volts nominal. It isn't
0.09 volts, it is 0.9 volts across each glow plug. Secondly, he carefully
pointed out that there is a resistance coil between the 12V source, behind
the dash, that drops the voltage 8.4 volts to at least 3.6V at the first
glow plug and then each glow plug reduces the voltage serially and equally.
I suspect the plugs are rated at 0.9 V but operate at slightly less than
that, but let's say they are supposed to operate at 0.9V to glow properly.
Without knowing the glow plug resistance, the coil resistance and the
intended current one can only guess what their respective values might be.
But lets say it takes 8.1 Watts (V X I = Watts or 0.9V x 9 amps = 8.1 Watts)
to make them glow properly. That implies approximately 9 amp current and
then each glow plug is 0.1 ohm to have 0.9V developed across it.  And the
coil would be aproximately 0.94 ohms. The coil under this scenario would
dissipate approximately 75.6 watts.  Voltage across the resitance/indicator
coil of 8.4 Volts x 9 amps = 75.6 watts. 

So if any glow plug failed all would not work and the indicator would not
light. Now if one has a high input resistance voltage meter and one or more
of the glow plugs has burned out and it is now completely open - very high
resistance, the voltage would read 12 volts at all glow plugs contacts until
one got to the second leg (the lead to the next plug) it would read 0 V.
That would tell you that the plug you have the lead on has failed. But a
better way to check this would be to use the VOM in resistance mode and
check the resistance of each plug. If any plug reads considerably higher or
very high compared to the others then it is the failed plug.

PS: All wires should be disconnected for this test. The last plug in the
chain can have its wire connected to ground and the ohm reading should be
the same across the plug as it is to ground. If not the grounding wire has
failed. If all plug contacts read 12 volts then either all have failed or
the ground wire isn't making a connection. Starting at the grounded plug the
voltages (referencing ground) should read something like 0.9 V on the first,
1.8V on the second, 2.7V on the third and 3.6V on the plug that connects to
the resistance coil. These may not be the exact numbers but the plugs should
all develop similar voltage drops. If they are not similar then something is
wrong. 

Hope this helps.  

 Dean A. Van Peursem
Snohomish, WA 98290

"He who makes decisions in haste repents at his leisure."

www.deerelegacy.com

http://members.cox.net/classicweb/email.htm

-----Original Message-----
From: at-bounces at lists.antique-tractor.com
[mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Kevin
Sent: Wednesday, December 06, 2006 5:23 PM
To: Antique tractor email discussion group
Subject: Re: [AT] IH B275 Diesel

Well if they say .09 Volt they aint like what I said. 460-560 IH Diesel, All

I was saying was how mine work.
If ya put a .09v light bulb on 12 v its going to glow very bright for a 
fraction of a second,
then won't glow at all any more. Wow wonder who was the brilliant mechanic 
that figgerd thatn out !  If its .09v you need to get the manual. Cause 
there has to be a resistor to get that low voltage.
What year is this tractor anyways ?
Dont seem like .09 volts would heat much in the summer.
Kevin Mosier

----- Original Message ----- 
From: "Dave Merchant" <nesys_com at ameritech.net>
To: "Antique tractor email discussion group" <at at lists.antique-tractor.com>;

"Antique tractor email discussion group" <at at lists.antique-tractor.com>
Sent: Wednesday, December 06, 2006 2:56 PM
Subject: Re: [AT] IH B275 Diesel

> It really sounds like these ones are wired in series (which is dumb, but 
> you work with what you got),
> so each one wants only a fraction of a volt.  As the plug says, 0.9 volt.
>
> If you put 12 V on one, it should glow very bright for a fraction of a 
> second,
> then won't glow at all any more.
>
> Dave Merchant
>
>
> At 08:40 AM 12/6/2006, Kevin wrote:
>>If these are like 460-560D they each need 12 volts, take one out and clip 
>>a jumper on pos terminal.
>>Touch the gloplug to the tractor, is good to have a cigar ready to light 
>>at this time for if the gloplug is good it will get red hot in seconds. If

>>not set it aside and try another. Once you find out which ones are good, 
>>get replacements for the bad. Then rewire the whole thing !
>>A poor man has poor ways
>>ironman
>>Kevin Mosier
>>----- Original Message ----- From: "Gus" <gibsongus at earthlink.net>
>>To: "Antique tractor email discussion group" 
>><at at lists.antique-tractor.com>
>>Sent: Tuesday, December 05, 2006 11:21 PM
>>Subject: Re: [AT] IH B275 Diesel
>>
>>
>>>John I have a B275 and I had to change some of the glplugs there are two 
>>>circuts in each plug hot to first plug ground to hot next plug and so one

>>>last plg is grounded...
>>>
>>>-----Original Message-----
>>>>From: John Kennedy <ihctractor at hotmail.com>
>>>>Sent: Dec 5, 2006 11:06 AM
>>>>To: at at lists.antique-tractor.com
>>>>Subject: Re: [AT] IH B275 Diesel
>>>>
>>>>I think that your plugs are grounded to the engine though the threads It
>>>>doesn't make any sence that the would be in series as they would only 
>>>>work
>>>>if you had 6 of them.  The wires going in and out of the plug are there 
>>>>so
>>>>that you can use one wire from the switch to light up all of the plugs.
>>>>
>>>>The last plug should only have one wire to it, it should not be 
>>>>grounded.
>>>>That will only ground out your hot wire to the plugs.
>>>>
>>>>A freind of mine who was Electrician always said I don't understand how
>>>>automotives wiring works with on one wire. I told that the frame was the
>>>>other wire, he still had a hard time understanding that.
>>
>>>AT mailing list
>>>Remembering Our Friend Cecil Monson 11-4-2005
>>>http://www.antique-tractor.com/mailman/listinfo/at
>>
>>_______________________________________________
>>AT mailing list
>>Remembering Our Friend Cecil Monson 11-4-2005
>>http://www.antique-tractor.com/mailman/listinfo/at
>
> Dave Merchant
> kosh at nesys.com
> nesys_com at ameritech.net
>
> http://www.nesys.com
> http://www.nesys.org
>
>
> _______________________________________________
> AT mailing list
> Remembering Our Friend Cecil Monson 11-4-2005
> http://www.antique-tractor.com/mailman/listinfo/at 

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