[AT] IH B275 Diesel

[Dean VP]

Ron:

We have made two assumptions here. Assumption one is that these glow plugs
are supposed to be wired in series. And the second is that they are rated at
0.9V. If either one of these assumptions is incorrect then we are fencing
with windmills and all that follows here will be incorrect. 

I just looked up some typical resistance on glow plugs and the ones I looked
at were 1.5 ohm at 12v or around 100 watts. To develop 100 watts at 0.9 V we
would have to have 110 amps of current. So something doesn't compute. What
is the part number of the replacement glow plug and what is it's wattage
and/or voltage rating? 

The reason the glow plugs are burning up is probably the coil (ballast
resistor between the 12V source and the first of the in series glow plugs)
resistance is not appropriate for the system and too much current is
flowing. For example if that coil is shorted out the lowest wattage rated
glow plug will blow out immediately. Which sounds like what is happening.
the coil resistance should be at least 10 times the resistance of the
individual glow plug resistance if the 0.9V rating has any merit which I am
beginning to doubt quite seriously. 


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
rdhaskell at juno.com
Sent: Monday, December 11, 2006 11:11 PM
To: at at lists.antique-tractor.com
Subject: Re: [AT] IH B275 Diesel

This crazy tractor is giving me fits.  I bought one new glow plug and
compared the resistance to my plugs and found I had two bad glow plugs. 
I also bought an new resistor/indicator.  Wired it according to the
diagram.  Tested it and the indicator did not show anything, checked the
voltage along the line and found number two glow plug (a new one) had
melted. Checked the wiring and everything was according to the diagram. 
Bought another glow plug and tried it again with the same results, number
two melted.  This system sucks, the voltages can only be checked when
energized but the glow plug only lasts a coupe of seconds.  Who would
know if there are 12v glow plugs that will fit directly in the head?  I
am even considering drilling these out to fit another design glow plug. 
Any advise?

Ron Haskell
rdhaskell at juno.com
Riverside, California
USA
http://albums.photo.epson.com/j/AlbumList?u=3009370&f=0
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