Radiator fan

[la nomade]

as i was driving back from the garage where i had the Horn fixed,the back up light and the radio....close to home,a blessing,the HOT came on,on the dashboard and i realised the fan was not coming on...parked,and found the radiator cover dripping and a sizzeling,hissing sound.....i hope it did not damage anything...the collant now cold is way down,i know it was full when i left home...can it be the thermostat?bad electrical connection???where is the thermostat located???looked in A. stream manual,no mention of Radiator nor radiator fan....Help!!!!thanks.

[masseyfarm]

BUMP

"the coolant now cold is way down,i know it was full when i left home..".

Had you just filled it? Did you check it after running the engine? If the heater core was leaking, or a vapour lock in system, the rad may have appeared full, until running engine.
Have you got an electric fan? or a Viscoses oil type?
The thermostat, as such, would not normally run the fan, as there would be a sending unit for the electric fan. This sending unit would probably be on the engine block.

Dave

Originally Posted by la nomade

as i was driving back from the garage where i had the Horn fixed,the back up light and the radio....close to home,a blessing,the HOT came on,on the dashboard and i realised the fan was not coming on...parked,and found the radiator cover dripping and a sizzeling,hissing sound.....i hope it did not damage anything...the collant now cold is way down,i know it was full when i left home...can it be the thermostat?bad electrical connection???where is the thermostat located???looked in A. stream manual,no mention of Radiator nor radiator fan....Help!!!!thanks.

[t7389sg]

If you did not hear the fan roaring when it got hot it would seem your fan clutch is not functioning. It’s easy to replace from the dog house. All it takes is a 1/2 inch wrench. I just replaced mine while at the Alumapalooza campsite. If you need a walk thru let me know because its all still fresh in my brain. Steve

[HowieE]

First you have to determine where the coolant was coming out.

Was it the cap, in which case it was just re leaving the pressure from over heating. Over heating could be bad thermostat, clogged radiator, or bad fan clutch.

Was it cracked radiator or hose leak.In which case the coolant level dropped to a point the engine overheated and boiled the remaining coolant.

Don't replace anything till you determine why.

[la nomade]

Originally Posted by t7389sg

If you did not hear the fan roaring when it got hot it would seem your fan clutch is not functioning. It’s easy to replace from the dog house. All it takes is a 1/2 inch wrench. I just replaced mine while at the Alumapalooza campsite. If you need a walk thru let me know because its all still fresh in my brain. Steve

thanks Steve,i hope that is all it is,i would appreciate a walk thru...your air stream looks very much like mine!!!My friends by now call it Martine's great folly because i keep having to fix things,if its not one thing its another,and yet....the love affair goes on,with no reason or rime.....

[la nomade]

Originally Posted by masseyfarm

BUMP

"the coolant now cold is way down,i know it was full when i left home..".

Had you just filled it? Did you check it after running the engine? If the heater core was leaking, or a vapour lock in system, the rad may have appeared full, until running engine.
Have you got an electric fan? or a Viscoses oil type?
The thermostat, as such, would not normally run the fan, as there would be a sending unit for the electric fan. This sending unit would probably be on the engine block.

Dave

quiet certain its a electric fan..will check for thermostat on engine bloc...thank you....will get my friend Don to come over to help me sort this out following all your suggestions...will keep you posted. M

[la nomade]

Originally Posted by HowieE

First you have to determine where the coolant was coming out.

Was it the cap, in which case it was just re leaving the pressure from over heating. Over heating could be bad thermostat, clogged radiator, or bad fan clutch.

Was it cracked radiator or hose leak.In which case the coolant level dropped to a point the engine overheated and boiled the remaining coolant.

Don't replace anything till you determine why.

Right....it was from the cap....will check it out thanks...love your mailbox!!!!

[t7389sg]

The fan you can see in the front of the radiator is usually the condenser fan for the ac. If you remove the dog house cover from inside the motorhome you can see the cooling fan behind the radiator. That fan is controlled by a fan clutch. When you first start the engine cold this fan should roar loud for a couple minutes and then calm down. It should get loud again when the engine gets hot while climbing a hill. The fan clutch seems to have a limited life on these big Moho. I too had the hot light come on in my rig so I am dealing with this too. It puked out its coolant into the overflow bottle and after filling that it all went on the ground. Check your overflow bottle and make sure there is a hose connected to the underside of the overflow bottle can to suck the coolant back into the radiator when it cools down. Mine was missing so the coolant only flowed one way. Steve

[DA TAZ]

I went through all the same trial and tribbulations with engine cooling a few years ago. I recored the radiator to a 4 core and while i jad it out i put a flex fan in. Big mistake! The moho sounds like a convair 990 at take off and man do those fans take hp. My current project is going all eletric on the fans. Just a heads up as you sort this out.

[dadstoy]

Originally Posted by DA TAZ

I went through all the same trial and tribbulations with engine cooling a few years ago. I recored the radiator to a 4 core and while i jad it out i put a flex fan in. Big mistake! The moho sounds like a convair 990 at take off and man do those fans take hp. My current project is going all eletric on the fans. Just a heads up as you sort this out.

Love those pics...nice!

[la nomade]

Originally Posted by t7389sg

The fan you can see in the front of the radiator is usually the condenser fan for the ac. If you remove the dog house cover from inside the motorhome you can see the cooling fan behind the radiator. That fan is controlled by a fan clutch. When you first start the engine cold this fan should roar loud for a couple minutes and then calm down. It should get loud again when the engine gets hot while climbing a hill. The fan clutch seems to have a limited life on these big Moho. I too had the hot light come on in my rig so I am dealing with this too. It puked out its coolant into the overflow bottle and after filling that it all went on the ground. Check your overflow bottle and make sure there is a hose connected to the underside of the overflow bottle can to suck the coolant back into the radiator when it cools down. Mine was missing so the coolant only flowed one way. Steve

it is the fan clutch,i ordered a new one...should come in the next few days,your help in finding the problem is so great,thank you....what a difficult access ....but i have great help to fix this.....M.

[t7389sg]

A couple of tips when changing this fan clutch out. Put a piece of cardboard under the fan on the ground to catch any bolts or washers you may drop. I did mine in a field so I had to be extra careful not to drop anything lest it disappear forever. My coach is very close to your model so you should have room once you remove the clutch to just hang the fan on the water pump pulley and maneuver the clutch up and out from around the AC compressor. Other than that it’s just a yoga class being stretched out over the doghouse reaching for those bolts. Not too hard compared to other projects I've done on this thing. Steve

[la nomade]

Originally Posted by t7389sg

A couple of tips when changing this fan clutch out. Put a piece of cardboard under the fan on the ground to catch any bolts or washers you may drop. I did mine in a field so I had to be extra careful not to drop anything lest it disappear forever. My coach is very close to your model so you should have room once you remove the clutch to just hang the fan on the water pump pulley and maneuver the clutch up and out from around the AC compressor. Other than that it’s just a yoga class being stretched out over the doghouse reaching for those bolts. Not too hard compared to other projects I've done on this thing. Steve

i am pleased to report that it is fixed,the new clutch went in,when tested,it did what it is supposed to do....all is well...thank you for your help with this,it made it all much easier....M.

[dadstoy]

Originally Posted by la nomade

i am pleased to report that it is fixed,the new clutch went in,when tested,it did what it is supposed to do....all is well...thank you for your help with this,it made it all much easier....M.

Glad you got it fixed. What manufacturer and part number was the replacement clutch fan? I'm not sure I'm happy with the second one I put on ;(

[la nomade]

Originally Posted by dadstoy

Glad you got it fixed. What manufacturer and part number was the replacement clutch fan? I'm not sure I'm happy with the second one I put on ;(

the fan clutch number is HTR 77276..did not look at who the manufacturer is....got it from Car Quest and it cost $ 68.83..it looked identical to the old one which now is in the local dump.....

[dadstoy]

Originally Posted by la nomade

the fan clutch number is HTR 77276..did not look at who the manufacturer is....got it from Car Quest and it cost $ 68.83..it looked identical to the old one which now is in the local dump.....

Thanks. That part number must be a carquest number only. I can't find any cross referenced number.