Re: [MV] Another CUCV glowplug story

From: chance wolf (chance_wolf@shaw.ca)
Date: Sat Dec 18 2004 - 11:07:55 PST


----- Original Message -----
From: "Mike" <michael@tsixroads.com>
To: "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Sent: Friday, December 17, 2004 10:50 PM
Subject: [MV] Another CUCV glowplug story

> I have been working on my M1010 glow plugs and though I
> would share my results so far. Mike
> Tishomingo, MS

The relays were made by Clum, and come in two styles: a bakelite sort of one
with the input/output terminals 'pointing at you' as you look at it, and a
silver 'canister' type one with a more traditional look. The black ones
seldom made it out of warranty period without failing, but nevertheless a
lot of CUCV family vehicles seem to have made it through their entire
service life and out through DRMO with the black one still fitted. If
anybody has one of those in their vehicle right now - change it today. It
will fail, and when it does, it tends to fail closed which means you'll be
changing 8 glow plugs pretty damn soon. Not something you want to have
happen on a cold night at 1am after your Christmas Party when you just want
to get home.

The silver ones fail too, but seem to fail "open" or otherwise make a really
poor contact. There's a Ford glow plug relay replacement with the same
footprint which you can get at NAPA called a "GPR109", if I remember another
lister's post correctly, and they seem to do the trick nicely.

The WAIT light thing is another story. If the batteries are low, the WAIT
light will stay on longer than usual, but if not, there are a few problems
you might be looking at. They had a lot of trouble with the temperature
sensor (back of the block near firewall) which kept the plugs energized too
long, and came out with a replacement type which also required a change of
harness plug that they generously included with the kit. You cut off the
old plug and leads, splice on the new one, and replace the temp switch with
the new one. I've only seen one through surplus channels, but evidently you
can get the parts from the Chev dealer any time you want.

Third issue is the card itself. Underneath the dashboard somewhere up
around the steering column or the fusebox is a black box containing a
circuit card. From what I've pieced together from manuals and stuff, the
card design is part of a very early Chevy "slow-glow" system which was
adopted for the CUCV trucks. Those cards have problems. The only physical
problem I've ever noticed after pulling a card is that one (or both) of the
electrolytic capacitors (look like blue miniature 'cans') are poorly
soldered to the board, but I think resoldering them only fixed the problems
in one of our trucks. The other boards had various problems from no wait
light to too long of a wait light to no relay trigger etc., etc. - and
rather than waste time trying to sort out which was which, I bought a couple
of new cards off the dealer for the first two trucks when I was really
naive, and now just ditch the works altogether in favour of a manual system.
Everything at work (six-seven CUCVs of all types) is now manual, and I've
not changed a glow plug in two years.

The Chev repair guys cringe as soon as you mention a 6.2 glow plug problem,
and most of them whisper in your ear just out of earshot of the Service
Manager that the wisest motorists have long since changed over to a manual
system.

Anyhow, mileage varies depending on differing experiences, as always, but
that lot's what I've found trying to keep the movie vehicles going over the
years. At one point when I was changing glow plugs out bi-weekly in an
effort to keep the automatic systems going, I had enough dead glow plugs to
construct a decent model of the Brooklyn Bridge. That got old real fast.



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