Can anyone give me details on where to plumb a Aux heater on a 525? I called merc and they were no help and nothing in the service manual for this motor either. Thx, Craig

For the motor or for the cabin ?

For the motor.

You mean for warming to prevent freeze damage?

I don’t think anyone’s asked this question before.

Apparently, I wasn’t clear what I am trying to do here, so let me try again…….

I am installing a cabin heater in my boat and need to plumb the two 5/8” hoses to the Cooling system on the motor. On a 496 which uses almost an identical crossover as the 525 there are two ports on the starboard side of the crossover that those hoses plumb into. On the 525 there is only one Port. From pictures that I have seen on other motors with Aux Heaters it appears that one of the hoses hooks up there, but not sure where the other hose hooks up to. A water heater hooks up the same way as a cabin heater does so if somebody has a water heater maybe they can look where those two hoses attached to?

In the picture, you can see where one of the hoses hooks up to the end of the heat exchanger and in the bottom right where the two hoses come in from a water heater in this boat. Hopefully this makes more sense now? Thx