1997 No Heat! Help!

I have a 1997 Ram and the heat has failed. It only blows cold air:banghead: . The mechanic replaced the thermostat and now does not know what the heating problem is. The air also switches from the body level to defrost when i hit the gas. Any help would be appreciated.

Josh

Okay...couple simple questions:

Have you checked the heater core (or had someone check it)?

Have you checked to see if there are any vacuum lines melted or damaged under the hood (mine was) to where the air comes out in various places...?

Have you taken the heater control out to see if anything is disconnected or the wire is broken (if there is one like there is in my 94)?

Check this 50MB+ download for answers also (thanks to Tony36):

http://www.neonix.org/nero/files/2001ramsrvcmanual.zip

Let me know...

- Ray -

your heat is controled by a mix door in the heater assy. by an electric servo. it opens the door for heat and closes for cool. the servo could be bad. it is located under the dash on pass side of trans hump right against the floor. the problem is if it is bad, you have to pull the dash and raise it up to get the servo off. It is an external part but its pushed against the floor and you need space to remove the screws.Removing the dash is not a big deal once you have done it before. The servo is a dealer only part and costs $125@. The change from floor to defrost(my truck is currently doing that) is probably what is called the heat/def actuator. It is inside the dash. If that is bad then when you accelerate it changes the vacuum to it. It is possable you have a vacuum leak elswhere, but is most likely the actuater. I priced them at around the $38-$78 range. If you need a little help pulling the dash follow the book, but you can contact me if you need to, I have done it many times and there are some shortcuts for what you may have to do.

Thanks a ton to both that have replied! I won't get a chance to look at it for at least a week. I will probably contact you if I run into any problems. Thanks again!:grinyes:

Keep us informed...if it hasn't happened...i'm sure it could happen...so elt us know what ya find out. :)

I told you I was having the problem also with the heater switching from floor to def., I finally found my problem, I had a vac line disconnected at the crossmember in front of the tranny. Did you solve your problem yet?

Funny...i just noticed it doing "something" strange in mine...like switching to defrost on its own (1994 RAM 1500)....

Will look around the trans & see what I find.

Funny...i just noticed it doing "something" strange in mine...like switching to defrost on its own (1994 RAM 1500)....

Will look around the trans & see what I find. Yah, that is an almost sure sign of vac leak. It goes to def with no vac on it's own and it takes vac to switch to other position. I've found that line at the cross member is prone to coming off especially if you have been through deep snow or mud. It simply pushes down onto the metal line, nothing to haold it there, so I took a plastic tie and put around it to hold it down. The line that came off on mine was to the disengagement for my transfer case. It would take forever to shift out and I had a check engine light come on and the tranny would shudder bad when cold, after I hooked it back up, everything cleared up.