Vansco output fault - Blower 1, Blower 2, Blower 3

[c_oneil]

I'm not sure if I have a problem with my dashboard fan or not. I have 3 flashing LEDs on the front Vansco at outputs #11, 12 & 13 and understand that to indicate a fault condition exists at those circuits. The schematic on the backside of the compartment cover lists those outputs as Blower 1, Blower 2 and Blower 3. The LEDs only flash when the dash fan is running at one of the 3 slow speeds. When I turn the dash fan to Hi or the mode selector to OFF(whick stops the fan) all three LEDs turn off. The blower fan seems to work fine at all four different speeds so do I need to look for a problem? I wouldn't want to damage my Vansco by neglect if this isn't normal.

[rrthor]

My thought is this is normal. Most people don't see it because they don't drive around with the cover removed. Both my current Vansco module and my spare exhibit this. My guess is my current module has been doing this for 11 years. I wrote EM about this and below is his response. I don't think he would mind if I post this. He has been very helpful to anyone who asks.

"The 3 VMM output circuits are tied (spliced) together after the output pins from the VMM and all are powered out for FanHi, and may be sensing a back-drive from each other &/or the fan when fan is On but either in FanMed or FanLo. Looks to me like the fan is driven one of two ways, either out of the VMM thru outputs 11, 12 & 13 for FanHi, or separately thru a block of resistors for FanMed or FanLo.

WRV may have done that to take advantage of the 6 amp max for each output (fan on high probably takes more than 10A so three 6A max sources provide a safety factor on a 10A+ load). FanMed & FanLo each drive the fan thru the resistors so the load is handled in some manner not thru the VMM, but because all are spliced together to the final fan power wire you (and I'm sure me and everybody else) is showing the back feed via flashing LEDs.

This appears to be normal and part of the design (WRV decided that you should be paying attention to other stuff while driving and not the flashing lights), & you don't seem to have any issue w/the operation end of the circuits."

[c_oneil]

I think you got it nailed. This would explain exactly what I see. My thanks to you and Mike.