Electric Radiator Fan. Running constantly. On Furnace/Starcool circuit

[Tech Tonics]

Greetings

I had a previous thread last weekend regarding some questions about the electrical system in my 2001 e250. This morning I replaced both house batteries and -hallelujah- everything turned back on and seems to be operating perfectly!

Except.

There’s a small radiator fan directly behind the front bumper. As soon as I connected the battery terminals the fan kicked on…and it hasn’t gone off.

Under the gaucho are the house-fuses. If I pull the 15a fuse for the Furnace system, that radiator fan shuts off. It also seems tied to the starcool system. (The main starcool fan sits directly under the drivers feet, that’s not the fan I’m talking about.

Van is currently plugged into shore power and starcool is turning on (and blowing cold air) as it’s designed. And the furnace also cycles on correctly when the thermostat calls for it.

Anyone have any idea? Maybe something to do with the thermostat?

[Tech Tonics]

Also, as soon as the van-motor starts, the fan stops.

Shut the van-motor off, and the fan goes on.

[1der]

And if you shut off the Starcool while on shore-power it shuts off?

I only have a light knowledge of Starcool but sounds like the fan upfront is being used to cool the a/c radiator up front since the SCool system utilizes both the factory A//C and the one hanging below the driver area.

[1der]

see page 12 of the Starcool manual courtesy of geofff
https://octopup.org/img/sportsmobile...ers-Manual.pdf

[Tech Tonics]

Originally Posted by 1der

And if you shut off the Starcool while on shore-power it shuts off?
.

Nope. Stays on. Only way to make the fan go off is to start the van’s engine (or pull the fuse).

[Tech Tonics]

Great info with starcool manual! Thanks.

It appears to be:

“AUXILIARY CONDENSER FAN
Locates under van. Blows ambient temperature ar across auxliary condenser so that compressed remgerant vapor will change to a liquid state before entenng vehice condenser.
WILL ONLY OPERATE WHEN:
• Starcool blower switch set to low, medium or high Thermostat set to "cool" and temperature selector set below intenor temperature.
• Vehicle ignition is "ofF.”

Except, the thermostat is set to “off” and the starcool blower switch is also set to “off”. (There’s also a main power switch for the starcool near the driver’s head which is also set to off.)

[1der]

Page 12 of the manual says it stays on - lower right side of page that shows the Condenser fan behind the grill. Sounds like it is normal.

Note, if your SCool is on and shorepower kicks off your batteries are going to be drained very quickly.

[Tech Tonics]

With no shore power, and starcool off at all 3 locations (thermostat, blower fan, main starcool switch) the fan stays on.

And it’ll stay on indefinitely.

I don’t think that fan is supposed to stay on for 24hrs when all other systems are off?

[Scalf77]

Have you messed with the thermostat lately? Sounds to me like a miss wire on the thermostat, or wire shorted. The RC and Y wires (usually brown) are for the Starcool. RH & W are for heat, one of those should be from the 12 volt heater fuse.

If you had the 12 volts on "RC" inadvertently, it would turn that fan on.

[1der]

I would expect that fan behind the grill should shut off when the SC3 is off.

At this point i think you have identified the problem and what likely drained your batteries. Scalf77 would have better insights as to how to isolate the component/sensor that is causing the fan to run. In the meantime I would install a switch or at least disconnect that fan so your batteries are not being drained.