Got my 2 new GPs today so tomorow I'll try to find out what the
problem is.
To refresh memory - I have new GPs and new GP relay - preglow light
goes out
within 1 sec. of turning the key)
That sounds like a problem internal to the GP relay. These things are
likely NOS, not new-new, and the timing capacitor could have aged to
death before you ever got it.
I got my DMM out and set it to
Resistance - using a new GP I touched the threads at the top and the
threads
that contact the cylinder head - got a reading of .3 - then I crossed
the
leads and the reading was .0 - is it OK that my DMM doesn't have a
reading
greater than .0?
Yes, you just cross the leads to find out what its idea of zero is, and
then subtract that from your reading.
How do I tell if my DMM will measure current in the range you
mentioned --
Was it exceedingly expensive? Then maybe. It's usually clearly written
on the face somewhere, if it does current at all.
I'm thinking I need at least a 30A max? But I think my DMM is good for
0A's - it's from Radio Shack --
Most DMM's have a 10A current scale, if they have anything at all.
To measure more requires a shunt, rarely seen these days, or a
relatively expensive clamp-on DC ammeter probe. Even my $300 Fluke
only goes to 10A without the 400A external probe (another $200 IIRC).
Attempts to measure more than 10A results in blowing its internal
fuse, an item that costs more than an entire DMM from Harbor Freight.
An old-fashioned charging gauge from the auto parts store could work,
those are usually 60A over a half-scale, so are a bit too crude to get
a good measurement off of. It would have detected my one bad one that
had 2x normal current, however.
-- Jim
