1999 S70 - No blower fan

[Mccjim12]

Hi All-

My blower stopped working in the ‘99 S70 base. First when the AC was on the fan would seem to not work at first but after leaving it on and drving a few minutes it would come back fine. AC also seemed to blow warm at times which I’m not sure is a coincidence (refrigerant level checks out despite rapid short cycling of compressor).

At a certain point I could not get AC to blow cold except on AUTO briefly. Shortly after there was no blower response when turning on climate controls. No hot air of cold air though the compressor can still be heard coming on if AC is selected. When turning dial though different air settings you can hear action under the dash from different vents opening and closing. I do get blinking lights on climate control panel but have for years. Checked fuses and all are good. A friend hooked fan to 12v power and it appeared to spin. Upon reinstallation blower worked intermittently for about a day then nothing again.

Tried a used eBay power stage to no success. Thinking about ordering up a new fan but a little baffled at this point. Wiring issues are out of my repertoire. Any help appreciated as always.


Jim

[RickHaleParker]

Unplug the wire from the blower motor. Jump it straight to +12V. If it runs like the Energizer bunny the problem is in the control circuits. If it still had issues its the motor.

[abscate]

On AUT the fan speed is controlled by the ECC control unit, so you may or may not get fan action. Vacuum put the little grille on the dash that detects cabin temperature , if that gets clogged it will inhibit climate control

Push the slider for fan far right and the fan should blow high, if it doesn’t there is work to be done - usually it’s just the fan

Read the codes from the ECC unit with a decent scanner or catch me on my BPT ALB run!

[misha]

Unplug the wire from the blower motor. Jump it straight to +12V. If it runs like the Energizer bunny the problem is in the control circuits. If it still had issues its the motor.

My experience says that faulty cabin fan will always work when connected directly to 12v.
The problem is that if it pulls too much current than it should...ecc will shut it off to protect the circuits and turns on flashing ac/rec lights because it stored dtc.

After lubricating the shaft and bearings with a bit of oil...it works properly for a while.

[abscate]

…and the ECC will record a nice code for excessive current to help you diagnose….

[RickHaleParker]

The problem is that if it pulls too much current than it should...ecc will shut it off to protect the circuits and turns on flashing ac/rec lights because it stored dtc.

Unplugging the wire from the blower motor. Isolates the ECC from the motor current.

[abscate]

I’ve got a parts 2000 coming but it will be on the wrong side of Long Island Sound