We will get ya all fixed up

One more question,

if you turn the blower on, it doesn't work. you pull the connector right then and it has power right? Plug it back in and still doesn' work? at the same time, you run a jumper wire and it works?

Just want to make sure I ask this right.

As far as I remember that'* correct, I pulled the connector and jumped the blower and it worked, put the onnector on and nothing had power everywhere as far as I could tell.

Check the voltage with the blower connected, either by using jumpers, or piercing the wires. Is it still good, or did it drop?

Everything was still good.

Blower motor grounds at G101 which I believe is the passenger side ground bus. I'll check that in a minute. Here'* a link to a Techinfo article that shows where to find the ground bus & how to clean it.
http://www.bonnevilleclub.com/forum/...=article&k=102

It was weird it would work for weeks and then one day it would be working and then all the sudden just stop, a few days would go by with it still not working then bam I'd get in and it'd be working or I'd be driving when it had been not working and all the sudden it would start working again. Then one day it just quit all together and hasn't worked since.

I'm looking at FSM for 98 Pontiac and it shows the blower grounding at G105. If the power can be applied to the power line (purple) on the blower using the normal black ground wire, that shoud indicate the G105 ground is okay.

The other thing I see is that this system uses a blower resistor set. That power oes through the blower relay until the relay is switched on for the high blower speed which is direct power from the 30A fuse int he Relay center on the firewall. Could it be a connection on the blower relay, #30 that feeds the purple wire that'* bad, cutting in and out? Or the relay itself?

There is only one ground involved. The pwoer to the Heater and AC control is power only involving no ground. As I said the only thing still in the circuit on both high speed and speeds 1-3 is the relay and its connections. The relay connection 87A is the input from the resistor to the relay. The relay connection 87 is the direct feed from the 30A firewall fuse.

Have you tried switching the relay with another same number relay under the hood? Such as the AC clutch relay? The blower motor relay is third from left, facing the firewall. The AC clutch is the left most relay.

Looks like 97'* grounded at G101 & changed to G105 in 98. I was wrong about g101 grounding at the passenger side ground bus, it actually grounds at the engine block next to the oil pressure sender.

Have you tried switching to manual operation by pressing the mode button & turning the fan to high speed?
Did you try running jumpers while the fan was mounted to the firewall?

My appologies, let me make a correction.

When checking power (purple wire) I get about 1 volt.
When jumpering power direct to the fan motor, the fan runs fine.

As far as the relays go, Yes, I have swapped out the fan relay without any change in symptoms. I will look at the tech article today.

Also I seen a post in this section about the outside temp reading 137 degrees, well mine is also reading that but at 157 degrees, however this problem with the blower fan happened looong before the temp reading started reading wrong.