Number47

Ok after much searching and test i still dont know why my heater doesnt work. my coolant flow is good. my blend door is moving stop to stop(did it manually and heard a thud) and my recur. door behind the glove box is moving(on Max A/C only) but i still don't have heat. now tomorrow i am going to drop the blower motor out and reach in there and see what i can feel. but if anyone has any ideas please tell me. my selector for defrost, dash and floor venting seems to be working but no heat. whats next?? Are there doors i'm missing??

thanks
brad

Number47

oh i forgot to mention when i was screwing with door behind the glove box with my hand i could get hot puffs or air out the vents. and yes my blower motor works

Doj Dewd

search harder - 'heater core' - it's been a real popular topic on here lately. . .

rage_blue

If you know your getting air blowing though your heater core, you may have a pluged heater core. I delt with that on a 98 gas 2nd gen.

jnicewan

what they said above, i know you said you checked coolant flow, but did you see if its circulating through heater core. its not real hard to remove rubber hoses toward back of eng above exh manifold and flush with a garden hose through hoses both ways. i also have heard of people uses a product like CLR pouring into core and letting set then flushing. if that doesnt work then its replacement time.

BIG DOG

I have the exact same problem. Temp seems to be the same going in and coming out of heater core. I did notice that when i turn on max a/c, i got heat but windows fog up. Why would that be? Does opening and closing the door behind the glove box redirect the air to the core?

Tazman

Number47,

Heater core, Heater core, Heater core.........

Been there done that. Exact syptoms. It's not that bad a job. Lot's of patience and consider doing the evaporator while you're in there.

I didn't try CLR as suggested above.....might work for you, but chances are the evaporator is ready as well. Not sure if this was corrected in 00, it certainly was pooched in my 98.5

mike1788

not jumping to far off the beaten path with this but any ideas as to why my ducts on the floor wont get any air on my 97? it blows great heat but only out of the defrost and the dash. if i put it on the dash/floor combo then it blows from the dash and the defrost but no floor. about 1.5 months ago my truck gelled up and while re-installing the fuel filter housing i broke a small hard plastic black hose that im guessing was a vacume line for the cruise control (the cruise doesnt react as fast as before i broke the line). i temp. fixed the line with a small piece of plastic hose but now im wondering if the heather controls run on the same vacume as the cruise. any pointers?

nickg

Likely your 4x4 wont engauge as well, also check to make sure you did not knock the main vacuum line off the pump. you could have other leaks in the vacuum lines, this will cause heater/cruise/4x4 issues

mike1788

the 4x4 works great all the time, havent ever had any problems with it... and i use it a lot. and the cruise works just takes awhile for it to pick up (if i set it at 60, it drops to 55 then picks back up to 60). i just wasnt sure if the heater control worked on the same vacuum as everything else. and if so, then why would it be able to switch to the dash but not the floor?

oneeye1977

I have a problem of the blower motor is working right and it switch direction right the heater core is about 1 1/2 years old but sometimes I get a good volume of air out the vents and sometime i get very little even on high? the othe day i noticed that my accumulator was covered in frost, does this have anything to do with the volume of air coming out the vents? I know that i do not have the system over charged wth freon so i know that snt the problem.

jnicewan

hey oneeye, sounds like your truck might be freezeing up. no matter what temp selction you set the air coming in passes through the evaporator core. if you see ice on the accumulator there is a good chance the evap core is frozen too. it basically forms ice on the core causing restricted or no air flow. you might check the clutch cycle switch. and you can unplug it to verify your concern.

nickg

Mine does the same thing and I know its overcharged so in the winter months to keep the evap from freezing I unplug the Hi-Low switch thats on the Air Dryer (near firewall pass side near ECM) If the Evap ices up you will have virtually no air flow into the cab.
If you know its not overcharges the Hi-low switch is likely faulty and keeping the compressor on causing the Evap to freeze.

oneeye1977

thanks i'll try it!

Stamey

Your problem is likely this: http://dodgeram.info/tsb/1996/24-16-96.htm
It happened on my 96. Replaced the actuator valve and now the floor vents work fine.

Chris