Engine Blower Fans not Working

[GB42Wishes]

The 2 Engine Blower Fans on my 1990 Grand Banks Classic just stopped working. Does anyone know if they are interconnected somehow? I have 12V a the source, but no current/amperage. Both Fans test good on the bench. They don't seem to be interconnected to the fire system either, so ruling that out for now.

 

[rgano]

If you have one breaker and one switch for ER fans, they are interconnected alright. Have you used a meter to check for volts at the fan locations using the engine as a ground for your meter? If you have power, the ground leg is your issue. If not, there is obviously a break in the positive leg.

As an aside, are the fans both blowing the same direction, or is one an exhaust and the other an intake. I learned early on that running my one exhaust fan while underway on my GB42 was a non-starter because the diesels were sucking far too much air to allow a fan to remove any. Burned it up in a trice.

 

[Comodave]

Is there a switch labeled for the bilge blowers? Or maybe another switch somewhere. Like Rich said put a volt meter on the wires and see if you have 12 volts or not.

 

[Steve1.0]

My 46 (1992) has separate breakers for port and stb. blowers. Both blowers (jabsco/par) were DOA when I purchased the boat. They don't seem to be very long lived.

 

[GB42Wishes]

I have 12 volts at the ends of terminal block where the fan connects, when I attach the wires of fan to the other side of the terminal block all voltage goes away. I have even tried removing the terminal block and connecting the wires directly together.

 

[Steve1.0]

Try connecting a spare bilge pump or similar 12v device. If it runs, the circut is ok and blowers are dead. If not the plot thickens.

 

[SteveK]

The 2 Engine Blower Fans on my 1990 Grand Banks Classic just stopped working. Does anyone know if they are interconnected somehow? I have 12V a the source, but no current/amperage. Both Fans test good on the bench. They don't seem to be interconnected to the fire system either, so ruling that out for now.

So they both work on the bench hooked to a battery. There is 12V at the terminal block. As soon as you connect at the installed location nothing happens. Sounds like an open ground.

 

[GB42Wishes]

Steve - That's what I'm guessing as this point as well. Now where to find it...

 

[SteveK]

Start by confirming it with a volt meter. Use a test wire clipped to + and both leads at fan connection. Also use test wire from a negative location to confirm a positive wire at fan connection point.
If either fail, trace the wire to a connection point.