I was wondering if there is a way to test the power stage (for the heater control) using a voltmeter/multi-meter. I ask this because I will be going to the boneyard here soon to pull a cooling fan, and I was going to grab a Power Stage, but I wanted to make sure it was good before I left.

Also - does anyone know the size of that alan/hex screw that holds the Power Stage to the firewall?

Thanks in advance!

(1995 Volvo 850)

 

Do you have ECC or MCC?

They are mounted in the duct work with a T15.

 

It's an ECC

 

well?

 

It's not allen or hex but "Torx".

 

Volvo ECC service info with testing procedures:

http://www.volvoclub.org.uk/tech/ser...ystem-Auto.pdf

Volvo 850 ECC climate control AC & heater system service manual

 

Yeah didn't see that at first.

 

Just didn't want you to make a mistake and go after it with an allen. I recently did my old pickups blend door motor and it was mostly by feel as you couldn't see up in there. There isn't much light or room under most dashboards.
Hopefully the info helped.

I remember something on DIY repairs to the power stage if it turns out to be the problem.

AWD - How to remanufacture your Blower powerstage yourself- final update