papadiesel
Full Access Member
Hey guys,
Many posts on this issue, usually the firewall vac motor for ac/ heat control. I need to know what the vac control motor is just up behind the control head ( inside firewall ) and if that is the one controlling floor defrost. 1989 Ford f250 7.3with factory AC. Vac is good throughout from the new coffee can to vac sector valve on head control. Mine is the two slider unit with cable actuating heat, cold. When I replaced the vac switch behind the head, I ran the system and saw movement on that vac motor, but it does not switch very well. It has two vac ports on it. Is this the culprit, should it move relatively quickly as all my other vac motors do? I am fairly familiar with these vac systems, but this has me stumped. The AC side works perfect moving to vents on demand and very cold. There is movement to defrost, mix and floor but it is not definite as it was before and blows poorly as a result. Thanks again! PS Cruise works perfect as well, the issue is only with the def/mix/floor motion! Also, moving from cool to heat works perfect as well.
Many posts on this issue, usually the firewall vac motor for ac/ heat control. I need to know what the vac control motor is just up behind the control head ( inside firewall ) and if that is the one controlling floor defrost. 1989 Ford f250 7.3with factory AC. Vac is good throughout from the new coffee can to vac sector valve on head control. Mine is the two slider unit with cable actuating heat, cold. When I replaced the vac switch behind the head, I ran the system and saw movement on that vac motor, but it does not switch very well. It has two vac ports on it. Is this the culprit, should it move relatively quickly as all my other vac motors do? I am fairly familiar with these vac systems, but this has me stumped. The AC side works perfect moving to vents on demand and very cold. There is movement to defrost, mix and floor but it is not definite as it was before and blows poorly as a result. Thanks again! PS Cruise works perfect as well, the issue is only with the def/mix/floor motion! Also, moving from cool to heat works perfect as well.