HMMWV Owners might want to read...

From: Chance Wolf (bigbadwolf@telus.net)
Date: Tue Jun 13 2006 - 18:27:49 PDT


So, went on a long trip with one of the HMMWVs from work which worked
flawlessly, but on the return swing of the trip I noticed an odor which had
exactly the same smell as when you try to dig some electronic component out
of epoxy with the end of a soldering iron. Stopped to check several times
on the side of the road but saw nothing obvious, and the smell came and
went.

Yesterday I fired it up to go into a muddy field and, when I got back and
shut it off, saw a curl of what I thought was steam coming from the hood. I
was wrong. It had a decent-sized underhood fire going on.

To make a long story short, I'd heard about fires caused by bad PCBs and the
like, but the cause of this one was really strange. The RPM/ Tach
transducer mounted at the back of the engine (where the distributor would be
in a gas engine) evidently wore itself out, and either due to an internal
short or heat generated by friction or a combination of the two managed to
set itself on fire, and from there ignited the insulation on the inner
surface of the doghouse. Fortunately someone speedier than I put it out
with a fire extinguisher before it became fully involved, so instead of a
pile of aluminum slag, now I'll only have to deal with the mess everything
made of the doghouse, the fuel line, some plastic vent lines and a section
of the wiring harness.

I'm going to remove them from the rest of the fleet and cap off the fitting
with something suitable, as I believe the transducer is only used with the
STE/ICE tester anyway, and I never use them. I don't know how other HMMWV
owners would go about testing their own save for a general check of slop
and/or heat discoloration, but I thought I'd mention it all the same.

(The funny thing is we had a bag of marshmallows in the Hummer to toast on
our trip, but never managed to cross paths with an appropriate fire. Guess
ya gotta be careful what you wish for... ;)



This archive was generated by hypermail 2.1.4 : Tue Jul 18 2006 - 21:47:12 PDT