I have the control unit installed but i am having some problems with it. The fan doesn't automatically turn on at temperature at all. But it does run when i connect the fan positive with the battery positive. Whats wrong and how do I fix it/test it??
What temperature do you have the DCC unit set to turn the fan on at? Is it the dcc unit w/ the knob or did you have to set jumpers? I think most of the newer ones have the knob.
Either way, since you know the fan works when given proper power, I'd first double check your installation and make sure that you hooked the wires up according to the diagram provided from Brian (the DCC creator).
If all of that checks out, I would pull the little sensor out of the radiator, drop the temperature setting to the lowest setting, and put the sensor in a cup of water a little hotter than the temp that you've set the controller to kick the fan on at. This, obviously, will test to make sure that the sensor is working properly.
Just curious, where did you mount the sensor? It should be on the inside of the radiator about an inch from the bottom hose (drivers side) and make sure you carefully press the fins of the radiator around the sensor.
Additionally, you may try some searches regarding your DCC issues. Brian has posted in quite a few of them sharing his expertise, which usually gets to the root of the problem fairly quickly. There were quite a few threads started with similar issues within the past couple of weeks. Not that the units are bad, it just seems that people have small issues which are usually easily corrected with the aid of a little more experienced person.
Don't give up, the DCC unit is good (I have one and it's worked well for a year and a half).
Good post from James. The probe is the first place to always check IMHO.
I havent considered using a cup of hot water for the probe testing - I wasn't sure if the probe was meant to be submerged in 190*F water.
Also, Brian has some tech on his site (like testing across the probe terminals to see if the probe seems to register). And an email to Brian always takes care of issues (I hope he has a list like JRichker and can just cut/paste what applies to the particular user).
Absolutely, check out Brian's troubleshooting section, it has some good things to check/rule out. Do you have the controller with the temperature set knob, or the jumpers? If you turn the AC on does the fan go on to 50% power? Make sure you follow the directions word for word.