Marine Air - afs code

[SailnMike]

I have a marine air air conditioning system that the code came up AFS. It is the airflow sensor but I cannot find any word on where the airflow sensor is and how to test or replace it.

Help, it's hot.

[transmitterdan]

There are two kinds.

One kind is a small black or brown plastic switch with a thin piece of metal that sits up next to the evaporator coil ( the bit that sweats a lot ). Air blowing through the coils pushes the metal flapper and closes the switch. The thin metal piece is easily broken off. There are two wires going to the plastic switch.

The other kind is sometimes on a boat but not that often. It’s not really an air flow sensor but a temperature sensor. If the evaporator gets too cold it will set of an alarm to prevent freezing. I doubt that is what you have.

The little metal flapper switch can usually be found at any decent urban AC parts store. Amazon have them I think.

There are quite a few air conditioner units in boats where the two wires are just shorted together because that flapper broke on a hot weekend and no time to find a replacement.

[SailnMike]

I have looked all over the Coil and traced every wire and I do not see any switches ?

and this is what I have, I turn the unit to cold and it comes on then blinks AFS for a second and then does nothing, no pump, no compressor, no fan. I can turn the fan on manually and it's blowing and then turn on the system and it doesn't do anything.

[SailnMike]

I see on the schematics there is an optional Alt Air Sensor ?
But there is not a plug in for that??

[SailnMike]

I have 5 wires going to the fan, could it be in the fan shroud ?

[transmitterdan]

If the fan does not run at all when first turned on then I think it must be some other problem. It has to spin the fan up to check the AFS sensor.

Some fans have speed sensors built in.

[SailnMike]

Yes Fan runs in manual mode

[SailnMike]

if the speed sensor in the fan can I bridge the two wire and bypass ?

[transmitterdan]

Originally Posted by SailnMike

if the speed sensor in the fan can I bridge the two wire and bypass ?

Probably not. If it is a speed sensor it makes pulses so the control module can calculate the speed.

In auto mode when you turn it on does the fan spin for a second or two and stop? If the fan does not turn at all in auto mode something else may be wrong. Like the control module.

[SailnMike]

Ok I got it !!

I went to p14 and turn on fan cycle w compressor and that bypasses the air flow sensor !!!!!

[SailnMike]

Thanks for the Help!