[AT] tractor electrical question

John Hall jtchall at nc.rr.com
Thu Aug 26 14:13:01 PDT 2021


Good reading!!!

On 8/26/2021 2:45 PM, Carl Szabelski wrote:
> https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=366678 
> <https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=366678> 
>
>
> https://www.hemmings.com/stories/article/ignition-coils 
> <https://www.hemmings.com/stories/article/ignition-coils>
>
> Did a quick search and found these two links. Hope they help to 
> understand how coils function.
>
> Carl
>
> On Thursday, August 26, 2021, Howard Pletcher <hrpletch at gmail.com 
> <mailto:hrpletch at gmail.com>> wrote:
>
>     I would concentrate on the coil first.  Defective new ones are not
>     unheard of.  Have you got another vehicle--tractor or car or
>     truck--that you could swap with. Any that has 6V to the coil when
>     running should work.  If it won't fit your mounting, just secure
>     it temporarily, be sure the case is well grounded, and see what
>     happens as it runs for a time.  And you can test the one from the
>     tractor in the donor vehicle.
>
>     Howard
>
>     On Wed, Aug 25, 2021 at 11:54 PM John Hall <jtchall at nc.rr.com
>     <mailto:jtchall at nc.rr.com>> wrote:
>
>         Ordered coil from CaseIH by the parts book is all I know. I
>         have the same issue with either coil. After reading about
>         ignition systems, it seems resistors are used in a different
>         circuit for once engine is running, voltage is dropped so as
>         not to burn points. 12 volts are sent for cranking only. I'm
>         wondering if there is a resistor somewhere thats failing when
>         it gets hot?
>
>         John Hall
>
>
>
>         On 8/25/2021 11:21 PM, Howard Pletcher wrote:
>>         Is that the original coil?
>>
>>         I'm not familiar with the 454, but in the truck world, most
>>         coils are intended for 6V use.  There is a resistor wire in
>>         the harness that drops the voltage while the current is
>>         flowing with the points closed.  But there are also coils
>>         intended for 12V use with no resistor wire.  If that is not
>>         the original coil, perhaps you have the wrong one.
>>
>>         Since it seems to work fine with 12V applied, I'd probably
>>         run another wire from the ignition switch to the coil to
>>         bypass any possible resistor wire.
>>
>>         Howard
>>
>>         On Wed, Aug 25, 2021 at 11:08 PM John Hall <jtchall at nc.rr.com
>>         <mailto:jtchall at nc.rr.com>> wrote:
>>
>>
>>             If there is, I can't find it. Closes thing I have found
>>             is the
>>             diode/rectifier for the alternator. Its inline and is
>>             tied in on this
>>             particular "circuit" . Matter of fact, the side opposite
>>             the alternator
>>             is where the fuel solenoid feeds from.
>>
>>             John Hall
>>
>>
>>             On 8/25/2021 11:05 PM, Spencer Yost wrote:
>>             > Maybe there’s an external resistor?
>>             >
>>             > Spencer
>>             >
>>             > Sent from my iPhone
>>             >
>>             >> On Aug 25, 2021, at 10:35 PM, John Hall
>>             <jtchall at nc.rr.com <mailto:jtchall at nc.rr.com>> wrote:
>>             >>
>>             >> Got what I hope is a simple question. On my IH 454
>>             tractor, is the voltage going to the coil a constant 12V?
>>             I'm having some issues with it running bad when it gets
>>             hot (I've already replaced everything but the plug
>>             wires). Found out today that if I run a jumper wire from
>>             battery to the coil, the problem goes away. Take it off
>>             problem comes back, put it back it goes away, take it
>>             off, it comes back. So I am tracing the wiring but this
>>             one isn't simple, new enough there are tons of gauges,
>>             fuel solenoids, safety switches, etc. Anyway, if I check
>>             voltage at the coil, the fuel solenoid, and there is one
>>             small terminal on starter solenoid that all read 12V if
>>             the switch is on. If I bump the engine over slightly (I
>>             guess the pts are closing) then the coil and starter drop
>>             to just under 6V, fuel solenoid stays the same. So
>>             shouldn't there always be 12V at the coil?
>>             >>
>>             >> John Hall
>>             >> _______________________________________________
>>             >> AT mailing list
>>             >> AT at lists.antique-tractor.com
>>             <mailto:AT at lists.antique-tractor.com>
>>             >>
>>             http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
>>             <http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com>
>>             >>
>>             > _______________________________________________
>>             > AT mailing list
>>             > AT at lists.antique-tractor.com
>>             <mailto:AT at lists.antique-tractor.com>
>>             >
>>             http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
>>             <http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com>
>>
>>             _______________________________________________
>>             AT mailing list
>>             AT at lists.antique-tractor.com
>>             <mailto:AT at lists.antique-tractor.com>
>>             http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
>>             <http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com>
>>
>>
>>
>>         -- 
>>         Howard
>>
>>         _______________________________________________
>>         AT mailing list
>>         AT at lists.antique-tractor.com  <mailto:AT at lists.antique-tractor.com>
>>         http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com  <http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com>
>
>         _______________________________________________
>         AT mailing list
>         AT at lists.antique-tractor.com <mailto:AT at lists.antique-tractor.com>
>         http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com
>         <http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com>
>
>
>
>     -- 
>     Howard
>
>
> _______________________________________________
> AT mailing list
> AT at lists.antique-tractor.com
> http://lists.antique-tractor.com/listinfo.cgi/at-antique-tractor.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.antique-tractor.com/pipermail/at-antique-tractor.com/attachments/20210826/0c73f73f/attachment.htm>


More information about the AT mailing list