cat 325b problem

hey fellas at work we have a 325b with digital heat/AC climate control usually seconds after its been started the fan starts blowing, yesterday i did nt turn on for over 2 hours and the display screen said it was on high, today when i started it the heater fan blew even with the power button pushed to the off position, i could just call it grumpy but i am curios why? thanks for any feed back i found this site a couple weeks age and have enjoyed learning and reading the post at least i know i am not the only one that has stuff break down

it seems to only do it when its cold out

I sounds like a grounding problem to me but those electronic controllers have a habit of doing strange things at times. As I recall the controller runs a couple of relays that control the outlet doors and the fan.

A "B" model is a little older machine as well. You could have some wiring problems causing the gremlins also.

Good Luck!

We have a 320BL with the digital controller, it did goofy stuff as well. Checked all the easy stuff, found no problems, figured it might be a contoller problem, it's been working flawlessly since. In my parts book, Cat calls it a "module", but it is the entire controller box. Pop out the old box, unplug it, popped a new one in, we we're good to go.