Slowly working on restoring a tired 97 TJ 4.0. When I got the jeep the blower was intermittent for about 30 minutes then never came back. When it did work, air seemed to blow decently out of the panel vents.
So....
For troubleshooting i used the field service manual, tested the H/S blower motor relay, A/C relay, blower motor switch and blower motor resistor and they all passed. I then bench tested the blower and determined the blower was bad (if i gave it a spin it would sometimes spin up a bit but it was weak). I replaced the blower with a new four seasons blower - afterwards it spun up and changes speed with the blower motor switch. Although i still cant get any air out of any vent. Ive changed out the hs blower motor and a/c relay to be safe and changed out the blower motor resistor. Still no air. Returned the relays back to originals
Not a vacuum leak...
Using a hand vacuum pump i pulled a vacuum on the line that connects to the vacuum reservoir and observed the 3 panel door actuators moving correctly (panel door, defrost/demist, floor). There was a second of hose that was very brittle - replaced and retested and vacuum holds well over 15-20 min.
What else works...
I checked the recirc air door actuator and that works fine (open/close). Blend door cable is good. Looking through the drivers side floor and moving the blend door to cold I can see the a/c evaporator.
Lost?
WIth the blower motor resistor out some air comes out of the hole. Doing a smoke test on the hood suction area it pulls the smoke into the blower housing.
Could the blower motor really be spinning in reverse? If so what could have changed that? Thank you much.
So....
For troubleshooting i used the field service manual, tested the H/S blower motor relay, A/C relay, blower motor switch and blower motor resistor and they all passed. I then bench tested the blower and determined the blower was bad (if i gave it a spin it would sometimes spin up a bit but it was weak). I replaced the blower with a new four seasons blower - afterwards it spun up and changes speed with the blower motor switch. Although i still cant get any air out of any vent. Ive changed out the hs blower motor and a/c relay to be safe and changed out the blower motor resistor. Still no air. Returned the relays back to originals
Not a vacuum leak...
Using a hand vacuum pump i pulled a vacuum on the line that connects to the vacuum reservoir and observed the 3 panel door actuators moving correctly (panel door, defrost/demist, floor). There was a second of hose that was very brittle - replaced and retested and vacuum holds well over 15-20 min.
What else works...
I checked the recirc air door actuator and that works fine (open/close). Blend door cable is good. Looking through the drivers side floor and moving the blend door to cold I can see the a/c evaporator.
Lost?
WIth the blower motor resistor out some air comes out of the hole. Doing a smoke test on the hood suction area it pulls the smoke into the blower housing.
Could the blower motor really be spinning in reverse? If so what could have changed that? Thank you much.
