Engine Blower Fan

[JonJG]

I have a 2003 Volvo Penta D2-55 fitted in a monohull sailing yacht. This is the standard VP set up so when should the blower kick in?
My understanding was when the engine ignition was on / motor running.
If not how is it controlIed as I don’t think this is related to temperature but to ensure sufficient air to the engine intake.
I have also noticed just how hot it gets inside the engine bay after a long motor run - 1hour plus. Should I be fitting an extractor fan too - to ensure a flow of air in the engine bay?
Any thoughts on when the blower should kick in?

[pcmm]

The engine blower will turn on when YOU turn on the blower switch. It would be unusual to have the blower come on automatically. The blower doesn't ensure sufficient air to the intake, it is used to remove excess heat from the engine room,

Its actually a good idea, but most boats aren't setup this way. Having said that I've got mine setup to turn on automatically when the iginition switch is on via a relay, but this is an unusual setup.

[Tin Tin]

In a diesel engine recreational sail boat the blower is used for sucking fresh air in and expelling warm air out. The fresh air intake goes to the the bottom of the engine room and the blower output exhausts from the high point in the engine room. You will find in the installation manual of your engine the manufacturer's recommended air circulation capacities. Usually the blower runs continuously and will come on with the ignition switch.

[Calif.Ted]

On a Catalina there's a switch under the instrument panel, on a Jeanneau it's wired to the ignition, depends on the boat builder more than engine type.

[JonJG]

Originally Posted by pcmm

The engine blower will turn on when YOU turn on the blower switch. It would be unusual to have the blower come on automatically. The blower doesn't ensure sufficient air to the intake, it is used to remove excess heat from the engine room,

Its actually a good idea, but most boats aren't setup this way. Having said that I've got mine setup to turn on automatically when the iginition switch is on via a relay, but this is an unusual setup.

Thanks PCMM. I don’t have a manual switch but I have discovered that my blower comes on with a relay switch control on the ignition switch on. I think will check that actuates first. Guess I am luck in that it does have an automatic system.