What is the pump thing under the hood on the passenger side fender right in front of the blower fan motor?

I have never really noticed it running until today on a cold start after it sAt for Few days.

 

Vacuum pump. Used to operate things like the HVAC controls or 4x4 (with ESOF)

 

Vacuum pump for the HVAC system and front auto hubs on 4WD.

The vac resevoir lost vacuum wihile sitting. It is auto start with a vac sensing switch.

 

mine also seems to run alot while i'm under the hood, key on. should it shut off after so long? and does it control the blower motor swith in any way. that just recentely started to only work on high. thanks

 

It shuts off automatically once the reservoir reaches a certain vacuum but I don't know the actual vacuum value.

Blower motor switch is purely electrical.

 

thanks robin, that makes sence on the pump, maybe i should check for some leaks.

also, which one do you think would be the first to go bad, the switch or the resistor.
looks like my to do list is growing when i get her in the garage

 

If the blower motor only runs on high it is most likely the resistor or bad connection at the resistor for lower speeds. On high the resistor is bypassed.

 

i'll try that. thanks again robin

 

Check the connector plugs at the resistor. They often get overheated and rusty. Then they won't pass current, or worse yet, get very hot and melt things.

If you put a new resistor in and reuse rusty connectors, the new resistor won't last long.

P.S. - Hi Robin. I've been out of touch for a while and it is nice to see you're still here!

 

Backatcha Jock. Until just a couple months ago I was off the forum for several months.