Date: Tue, 16 Jan 2001 00:19:49 -0500
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: Ground wire from heater blower warm
In-Reply-To: <25.ffc52bd.2794ff8a@aol.com>
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At 08:36 PM 1/15/2001, Ken Hunter wrote:
>In a message dated 01/15/2001 3:06:40 PM Mountain Standard Time,
>dbeierl@attglobal.net writes:
>
><<
> Probably not, but you can measure -- the motor draws just about twelve amps
> at high speed. >>
>David, my VOM only goes to 10A DC. Is there a shunt I can use to measure
>higher DC amps?
You can buy shunts, but they're not cheap. You can make one good enough
for your purpose with #18 wire. Take a piece a bit longer than 20" and
stretch it out on a board. Measure 19.2" and solder two wires at that
distance to go to your voltmeter. Solder bigger wires (16 or 14 ga) to the
ends and crimp a male terminal on one end and female on the other.
This will give you ten millivolts per amp at some standard temp, prolly
20C/68F. It will rise as the wire heats up. Keep it pinned to the board
so it doesn't coil up. You can zigzag it around nails to make it more compact.
>Also, is there a liquid chemical that will clean corrosion
>off the ground connections? I can clean up the ground junction but the female
>spade connectors are tough to get at.
If they're reasonably tight (and you can pinch them a bit if not) just
plugging and unplugging gives a good mechanical cleaning to both male and
female. The crimp itself, however, may very well be going bad. There you
have to remove it, clean the strands of the wire (a stinking nuisance but
you *have to*) and crimp a new terminal on.
>There was a 25A fuse on the blower circuit and it was on the hot side of warm
>to the touch.
That fuse is *supposed* to be no bigger than 16 amps (if it's in position
10) and believe it or not 8 amps if it's in position 13 (in '82 the blower
is on S13 by itself and the rear defroster is on S10 with the wiper and
washer. In '83 they swapped blower and defroster, I presume because people
kept blowing the fuse. The fuse will be too hot to touch, probably. I
will publicly state here that VW screwed up this one -- the blower
high-speed needs its own 16-amp circuit, and it needs not to run through
the blower switch which is not heavy enough either. That's the plain
yellow wire from the switch to the blower -- I recommend to cut it and use
the switch end to drive terminal 85 or 86 of a relay, the other going to
ground. The blower end goes to terminal 87 and you run a separate fused
circuit from the panel to terminal 30 on the relay.
>I replaced the heater core two years ago (before joining the
>list) and shoulda/coulda easily checked out and lubed the motor then. This
>problem has been getting my attention lately with the bad NM weather. When I
>turn the heater switch to high the lights will dim and the wipers will slow
>down.
That ain't right. And it's wrong, too, and shouldn't be. I wouldn't even
bother building the shunt, I'd go hunting for voltage drops (and build the
shunt later, it's useful). If it's killing the lights too then it's not
the load reduction relay. There's a twinned Bk/Y wire to the light
switch. Check the drop between there (X terminal on switch) and the X
terminal on the ignition switch. Put your probes on the actual switch
terminals, not the wire terminal. If that's it, find out which terminal
has the big drop (could be both) and fix.
If it's good, measure from X terminal to 30 terminal on ign switch. If
bad, bad switch. Then the 10-ga red wire from the 30 terminal back to the
fuse panel. Then the 8-ga red from there to the glow-plug fuse. I doubt
it's beyond there, as the glow plugs draw some big chunk of 50 amps...
>I might mention also that when I unscrewed the ground cluster that the
>motor was on the motor kept running.
It was grounding through something else like the radiator fan that was also
plugged into that cluster.
>Thanks for your help,
Yr welcome, let me know wha' hoppen.
d
>Ken Hunter
>82 Westy 1.9D
>84 Jetta 1.5D
David Beierl - Providence, RI
http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"
