2000 Jeep Cherokee XJ Sport 4x4 w/ 4.0L & Auto Trans

My blower motor went out a week ago or so. I live in Phx, AZ, so this is no laughing matter. This is our only vehicle and we have 2 small children so, needless to say, this needs to be fixed ASAP.

Here's what I've done so far:
1. My first thought was to check the connection at the motor. I couldn't get the connector to let go (even though it was loose - not welded), so I pulled the motor to get a better angle. Got the connector off and checked out the motor. Internal wiring was toast. Bought a new motor. It spins now, but it cuts in and out every 10 seconds or so like clockwork. If I move the switch through the speeds, changing speeds every 2 seconds or so, it doesn't cut out.

2. Cut the old connector off and put on standard push-on connectors. No change.

3. Swapped out the blower motor relay. No change.

4. Swapped out blower motor resistor. No change.

5. I used a test light to check power at the fan. It is constant. Light stays on when motor cuts out.

6. Autozone guy recommended a new motor, so I swapped it out again. No change.

I've been told to use a volt meter to check voltage at the motor. I can do that, but I have no idea what it's supposed to be.

I've also been told to check the ground, but I don't know where it is.

Today, the plan is to swap out the switch.

Has anyone ever had this problem? Does anyone have a recommendation as to what to check? Any help will be greatly appreciated. Thanks, in advance.

 

two wires in the plug correct ones pos ones ground hook test light to pos post on battery check other wire that simple