No defrost on a 2000 Base S70

[scot850]

Let us know how it works.

I have traced the wires to the larger of the 2 connectors to the rear of the ECC unit and so will add this info to the write up when I get some more time. That way we may be able to check motor operation by removing say the resistor pack and blowing air into the system through the hole and then using a 12V source (battery charger set to 2A?) be able to power the 2 pins for the servo motor without dash dismantling to check if the motors work without the ECC unit attached. It would be a way to eliminate the ECC unit from being the issue and help which if any motors are not working.

Neil.

[leftyref56]

Neil,

Thanks for that info. i look forward to the write up.

Bob

[leftyref56]

Update:
I put the car back together with vents in the mostly defrost position. it is good to have my Volvo back! There were no blinking lights upon starting. When I turned the knob to defrost on the ECC the air conditioner started, but here was no movement of the motor, so I guess the motor is bad. i am going to try to find a used one and take everything apart again. At least it will be easier this time since I have already done it once.

[abscate]

The motor comes out without taking too Much ECC apart. You can also pull the plug and check/apply 12V to the motor to check it too

The transistor pack which controls the fan speed also

I have spares for sale / karmic gift in the spare threads too , thread called part out 1999 v70