MattJS

I have a 2000 ML430 with the 4.3L V8. I have been having trouble with the electric fans mounted on the condenser, the fans pretty much come on when they want to. When the fans are running the A/C is very cold but when the fans are off it only blows warm air. When the fans do kick on the come on strong and have no visible issues. I have checked relay K26 which is for the fans and it is good. I checked all other fuses and relays pertaining to the A/C system and they are all good. When the fans do kick on they stay on, I turn off the a/c and turn it back on the fans won't kick in so the a/c starts blowing warm air again. Its like the fans are intermittent but work great when the decide to kick on. Could it be the fans themselves?

Any suggestions or help would be greatly appreciated.

art_arev

Make sure you have enough gas in the AC system.

MattJS

I have had the A/C checked, there are no leaks and the freon is where it should be at.

Maj. Dundee

Every time you request A/C, do the fans eventually come on?

The actuation of the fans ON depends on the refrigerant pressure PSI and or coolant temp. Once it reaches that threshold the fans will remain on unless you are driving at hwy. speeds, at which time they will shut down and the onrush of air will lower the readings.

MattJS

Not everytime when you have the A/C on due the fans kick on.

Maj. Dundee

Matt, this is a poor explanation. Working with a cold eng., open the hood and start the engine and request A/C.

Let the eng. run for approx 2 mins. Do the two elec. fans come on?

Feel the two aluminum pipes at the firewall. One should be hot and the other cold.

Do the fans run continuously and are the pipes hot and cold? Even if the fans shut off, are the pipes still hot and cold?