# constant rv motor/fan/compressor/thingy



## delboy57 (May 1, 2005)

hi all, we have a rockwood bayport with the chevy v8 6.5 litre turbo engine. when i turn on the ignition a small motor in the engine compartment clicks in and runs a fan for a few seconds, once the engine starts this then clicks in approx every 35 seconds for approx 3 seconds (ive timed it). when i look at the engine compartment it is mounted on the mid right of the bulkhead it is approx 9" long by 3" diameter with the fan part on the left. (see pic 1). there is a 1/2" rubber tube going from this right across the bulkhead to the left hand side where it fits on to what looks like the ball off a toilet ballcock.(see pic 2). there are two wires coming out of the right hand end of the fan/motor, a black one which goes to an earth point on the bulkhead and a red one which goes to a switch of some sort mounted on the bulkhead (see pic 3). this switch has another red wire which disappears through the bulkhead into the cab it also has a thin plastic tube coming out to a rubber t piece which has two more plastic tubes, one follows the red wire into the cab and the other goes off to the left (i think it may also go to the ball along with the 1/2" rubber tube). there is also a cylidrical/spherical gubbins below the ballcock ball which has a plastic tube going to it and this tube appears to have disintergrated. my question is, does anyone know what this fan/motor is? what function does it perform and should it keep coming on like this and if it shouldnt has anyone got any idea of how to fix it. sorry to be so long winded, cheers, derek


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## damondunc (Feb 14, 2006)

The pump/motor is a vacuum pump which supplies vacuum to the heater directional control ie which way the output from the heater is directed, the vacuum is what moves the flaps in the heater box. The black ball is a vacuum resevoir and if you have a split/perished pipe the pump will run nearly all the time. In other words you have a vacuum leak,replace the offending pipe and turn on the ignition and wait for the pump to stop, then turn the ignition off and listen for any hissing which would indicate another leak. Fix this pronto if you leave it you will burn out the pump and they are expensive! 
Dunc.


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## sallytrafic (Jan 17, 2006)

*Saw this and thought of you!*

>cast out those Demons Damon<



Regards Frank


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## sallytrafic (Jan 17, 2006)

URLs now fixed see previous post

Frank


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