Auxilary fan always runs

[burt ragio]

I replaced the water pump & thermostat added coolant fluid elevated front of car a bit and burped the system through two heat/cool cycles & added more coolant fluid. My concern is after the motor warms up it does not overheat but the aux fan continuosly runs. I don't recall if it always ran after the engine got to normal operating temp. The air temps are now apx 62 degrees. Is it normal for the aux fan to continuosly run ?

[Zack]

Is your AC on?

[burt ragio]

No the AC is not on.

[SC Cheesehead]

Sounds like a similar issue to what bigdogjim had during MV8. You may want to send him a PM, also one to 03mmmonroe, he did the diagnosis and the repairs.

[djv5150]

I had the same issue it is the Bosch fan speed controller on the front of the fan shroud I had an old one from my old 03 CV and replaced it trouble stoped
see my old post. page 2
http://www.mercurymarauder.net/forums/showthread.php?t=61950

[fastblackmerc]

Whatever you do DO NOT, I repeat, DO NOT buy an aftermarket fan unit. They have a tendency to have "thermal events".

[FordNut]

Open the fuse box cover and tap on the relays. See if you find one that causes the fan to switch off & on. I found one on my wife's MM like that, replaced the relay and fixed it.

[burt ragio]

Thanks for all the help. I changed the 50 amp relay at the tune of local Ford stealer cost $17.98 and I think I am good as gold again. What mark up. I should have listened to Zack & taken a walk through a junk yard. Just think how many cups of coffee that conveince cost me.