Heater only blows thru dashboard vents, won't defrost
I own a 1995 Pontiac Grand Am. The radiator cracked and I had to have a new radiator installed, yesterday, 31Dec08. With the new radiator, the heater works okay, but I cannot direct the heater airflow with the right heater control knob. The heater only projects an airflow through the instrument panel outlets. When I put the dial to defrost, no air comes out of the defroster vents, the airflow continues to come out of the instrumet panel outlets only. It is as if the control knob only operates in the "vent" mode, no matter where I position the dial.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
yes --it is a common thing
the transmission oil cooler is in one of the radiator tanks and have a habit if cracking allowing the transmission oil to mix with the coolant
the fix is a new radiator and a very good wash out of the cooling system ( heater included)
I suggest that you use an accredited radiator shop and have then do the flush and the radiator replacement
remove as followed :
1- upper trans cooler line.
2-upper radiator hose.
3-lower trans cooler line.
4-cooling fan electrical connection and retaining bolts .
6-splash guard below lower radiator hose .
7-lower radiator hose from radiator.
8-condenser line retaining clip.
9- condenser to radiator bolts .
10-coolant tank small hose from the radiator .
11-radiator retaining bolts.
That's it. feel free to contact me I did this removal more than five times to your grand am type specifically .
Vacuum vents not working:
Your vent controller is not working. Is theair coming out the defrost vents? If yes, this is the default when there is novacuum to the switch. In this case, check the small plastic vacuum line that isconnected to the engine intake manifold and going into the firewall. Make surethis line is connected to the manifold and the hose is not cracked. If this isgood, go inside the car and see if you can trace that line to the control switch. If theline is good to the switch, see if you can pull the vacuum connector from theswitch for troubleshooting. with the engine on, check for vacuum on the linefrom the engine with your finger. If the vacuum is there, your switch isprobably leaking and needs to be replace. Any other questions, please reply.
it maybe a hose not installed correctly, if it is a v-6 check the intake gaskets for signs of leaking, when you over heat the engine, automatically replace the thermostat, the cooling fans may have a hand in the overheating issue, they may not be turning on due fan motor failure, check cooling fan fuses, very rarely does the coolant temp sensor give out and if it has, that would also be the reason the cooling fans are not coming on, a cracked radiator is also common on gm or any other radiator with plastic tanks. good luck
first check to make sure that the hose,s back there didn't crack / of there fine then the heater core has blowen open and is know leaking / if you are in an aera that diesn't get real cold take the hoses off and route one to the other till you can get it fixed
its located on heater box, there are 3, what you do is watch each one as you move selector to vent ,deforost, hot cold etc, watch to see which one is no moving.should be on drivers side. hope this helps.