New Member, A/C question on '98 GT

[Wolfpack]

Hello everyone. I've had my white 1998 GT since 2004 and have a Dark Forest Green 1999 GTP I just bought in March. Both of them 4 doors. Only mod on both is an aftermarket air intake.

My question is this. For the past 2 years the '98 hasn't had strong air coming out on neither a/c or heat. I replaced the blower motor and it didn't really help. I just replaced the blower motor control module and it still didn't help. It blows cold and hot, just has very reduced air flow.

[Fivefingerdeathpunch]

Try checking over the blend doors.

[Wolfpack]

Try checking over the blend doors.

Is there a lot involved with that? I have a repair manual at home, but I'm no mechanic.

[Wolfpack]

When I looked over the repair manual it seemed like the blend doors just control the temperature. Does the temperature actuator control where the air flow goes. Like if I set it to the vents? Is it possible if the actuator's go bad that the air flow is just not working correctly? I'd just hate to buy 2 new actuator's and it still not fix the problem.

From this thread: http://www.grandprixforums.net/blend...ent-21941.html
I can't tell if this is what I need to do.

[Fivefingerdeathpunch]

Yes, the blend doors tell the air where it needs to go.

Try inspecting them to see if they are working correctly and I believe on the pass side of the engine bay there is a vacuum line that runs down and connects to part of the system, sometimes that is broken or knocked off.

[Scottydoggs]

the blend door actuators only control hot or cold. nothing to do with speed of air flow.

if your def, vent, floor setting are not working right chances are you have a broken vac line to one of the vac pumps that do move the air from setting to setting.

or theres a rats nest in the air box blocking it up. long shot there lol

the round thing with the tube off the top and the arm leading up, it is the vac pump in this pic

same thing on the other side.

this vac tube runs out the pass side fender around the battery across the bumper, then to a round ball in the d/s fender.

[Wolfpack]

Is the vac pump in the pic close to the blower motor in the passenger foot well?

[Scottydoggs]

in this pic the vac pump is further up towards the center console. see the lines in the top of the pic, those would go to the vac pump on the pass side.



if you take out the glove box you can get a pretty good look at it, with he car running work the controls and watch the lever that comes out of the top, it moves the air from def, to vent to floor, and the blend combo's, vent floor, def/ floor.

[Wolfpack]

It looks like the arm is moving when I change settings, except it doesn't look like it moves when I go from the floor setting to the vent setting.

[Scottydoggs]

when you have it set to vent is the floor still blowing softly? or the defroster?

im thinking your air flow is being directed to 2 places. that makes the fan less powerful feeling.

[Wolfpack]

when you have it set to vent is the floor still blowing softly? or the defroster?

im thinking your air flow is being directed to 2 places. that makes the fan less powerful feeling.

Yes, it still feels like quite a bit coming out of the floor.

[Wolfpack]

I just checked it again. When the setting is at floor, vent, or both, the air flow is same coming from the floor with very little coming through the vents. And the arm doesn't move.

[Scottydoggs]

i'd have to think your problem is related to a bad vac pump or broken linkage.

if you can get the vac tube off, and put another tube on the pump, if you blow or suck the tube the arm should move.

you could even try to take the arm off, be careful with it so you dont break it, i've never had to take one off so i cant help with that part, but once its off work the linkage by hand and see if you get air to flow all at once to one setting or another.