I'm troubleshooting what appears to be a low amps problem to an AC
blower motor on an '03 Spectra.

With the blower disconnected, I can put a multimeter across the pig
tail and read 13V when the fan knob is at any of the positions other
than off.  When I plug the blower fan back in and try to take a
reading from the back of the pigtail, I get about 0.3V in all
positions except the off position where I read 0V. I have been able to
hot-wire the blower by connecting it directly to the cigarette lighter
socket and it works fine.

I thought maybe it might have been the blower resistor.  I tested all
3 points on it and read 1.7 Ohms, 1.0 Ohms and 0.6 Ohms.  I don't know
what the reading is supposed to be because the resistor is just a
circuit board with a bunch of zig-zagged trace lines with no
components on it.

I then bypassed the resistor by jumpering across it with a piece of
wire, which should have been the equivalent of the fan in the high
position, but there was no difference. The fan didn't spin or even
twitch.

Before the fan went completely dead, it cut out for a few days but
then came back on when the car was driven over some railroad tracks
for about a day and then died again when hitting a pot hole and hasn't
worked since.

This reminds me of something like when you have a set of cheap jumper
cables and you can't get the engine to turn over but when you use a
good set of thick gauge cables you can start the car fine.

I checked all the associated fuses and even put another relay in the
AC blower socket.  Nothing has helped at all.  If anyone has anything
else to try, I'd appreciate some input.  Otherwise I'm going to end up
getting a cigarette lighter plug, some lamp cord and two female spade
connectors and rigging that up.