Vessel- This is on a 2006 41 CMY with twin gas engines. It has four blowers, four breakers on helm breaker panel, one blower switch on instrument panel (main on and off for all four), and one switch on the dc panel in the salon you can use to turn on blower prior to starting genset.

Problem - tried to turn fans on. All four breaker switch’s on, main power for dc panel on, instrument panel switch turned on. Fire extinguisher light comes on, light in instrument switch on- nothing from blowers.

Tried with switch on dc panel in salon- no light on switch and no blowers

Read in forum about blower #1 must be on, so tried, nothing, then #2. It ran! Three-nothing. Four-nothing

Started engines. Usually light on instrument switch comes on when engines are on. Blower still ran but no,light

Turned off engine and blower switch #1 & #2. Tried to turn blower on again, nothing, tried all sorts of combinations - nothing. Thought a relay might have overheated, so waited a while- nothing.

So, I’m sure I have power at main dc panel on switch. (Horns and everything else works) Pretty sure I have power at four blower switches, (a blower ran) at least in the first one because light comes on in instrument panel switch. Pretty sure in at least the manual on position I have power at the instrument panel switch.

I don’t think all four blowers would die at once. And # 2 blower worked at least for a little while. The light for the blower switch in the main dc panel does not come on in any configuration.

I’ve read about relays in these forums. Are they next to the blower motors in the bilge?

My first mate and I are 95% sure when we got back to the dock, yesterday, no blowers were on. I don’t recall turning them off. They are usually so loud you can’t forget to turn them off. I did run them for four minutes prior to departing and all was fine.

Thoughts?