I have developed and intermittent problem with my HVAC blower motor. On average the blower will not come on at one of every 10 starts.

I have checked the fuse. I have adjusted the ECCU settings into "manual" and cycled both TEMP knobs as well as the air location distribution knobs. This has no effect.

Sometimes the blower will start, if I turn off and restart the engine one or more times. Other times, this will not work.

Has anyone else had/solved this problem?

Is there a relay in the system, which may be the culprit? Might it be the blower motor resistor? Is my ECCU beginning to fail?
--
Dave in Virginia; 1998 V70 T5(M): IPD MOTRONIC+ ECU Upgrade, Sport Muffler, IPD Strut Tower Brace; VDO Boost Gauge, IPD Anti-Sway Bars, Rocha ABS Control Unit, Koni FDS Struts and Shocks/// 1988 245 DL Wagon// 1967 MGB Roadster

If the blower motor doesn't make a lot of noise when it runs, I would suspect the "resistor".
http://www.fcpgroton.com/product-exec/product_id/31846/nm/Volvo_V70_Blower_Motor_Resistor_models_with_Climate_Control/category_id/66

The resistor is to the left of the blower, the white fins are in the air flow from the blower to keep it cool. One of the reasons why recirc should not be used when the heat is on.

You can check the fan motor by plugging it into 12V directly from the battery, this is for high speed only.

Did you try just moving the blower speed to max?

Klaus
--
Common sense trumps a PhD

Thanks for the insights, Klaus.

The blower does not make any unusual noises. I have never used RECIRC when heating. Never that cold here in Hampton Roads VA

When this problem has occured, I have moved the fan control from AUTO through the entire range of MANUAL speed settings and back several times. No effect.

I will have a look at the blower and resistor.
--
Dave in Virginia; 1998 V70 T5(M): IPD MOTRONIC+ ECU Upgrade, Sport Muffler, IPD Strut Tower Brace; VDO Boost Gauge, IPD Anti-Sway Bars, Rocha ABS Control Unit, Koni FDS Struts and Shocks/// 1988 245 DL Wagon// 1967 MGB Roadster