i bought a 02 harley truck and i love it. but now thats its cold i found out that the floor vents dont work they go straight to defrost when the floor or panel/floor is selected. i was told it was a vacumn problem. how do i go about diagnosing and fixing the problem. thanks troy

 

Does it blow out the defrost vents all the time, or just when you put it on floor/defrost? If it does it all the time it is a vacuum supply issue. If it only does it in that position you probably have a problem with the control head or the cold weather is causing something to not seal very well somewhere else. The vacuum lines that feed the HVAC controls are behind the battery. It is not uncommon to find them rotten, leaking, or completely broken. There are two or three check valves back there that could also be bad, but they usually cause the airflow to go to defrost under periods of heavy throttle.

 

it only goes to defrost when i put it on floor. everything else works fine def., panel,all of that work just floor doesnt when i put it on floor it goes straight to defrost

 

socks?

Just kidding...

Look at the silver ufo shaped thingy that sits above the diverter bow (behind the radio) and see if the line there is fubar....or....as a last result, grab the linkage on the driver side of the box and see if you can manually move the flap. If you can, but it is difficult, the actuator may have blown the diaphragm. If you can't, look for a dead rat carcas impeding the flap.....and wear thicker socks!

 

thanks man i'll check it out. i'll let you know if i find a rat. lol