No A/c, only hot and hotter!

[indyhog]

My 98 has turned into a sauna. It is only blowing hot air now. I checked the R134a pressure and thats ok. Everything on the engine side of the firewall seems to be working (accumulator is ice cold). I am suspicious of the the componets in heater box underneth the dash. Anyone, any thoughts or similar experiences?

How labourius is dash panel(s) remove?


...I had just gotten it back from the shop where they had to replace all bearing in the rear end...Doh.

[Chris Stewart]

If you have Climate Control, you might try disconnecting the battery the reconnecting it..........thanks Robmoo.
You might also check under the hood for a disconnected vacuum line around the motor and firewall.

[glathrop]

I have a 98 and behind the glove box door there's a little black
electric motor which moves a door in the heater box. This motor my be broken. The gears in the motor are plastic and break easily.
Unfor the little motor is a dealer item. And is about 175.00
But you can tell if it is not working by running the AC and watching
and listening to that motor while turning your climat control.
George

[ctesla]

george said it.
turn A/C on max, but fan blower to nothing.
now feel up in the lower vents (cold right?)
turn blower on one step at a time.
it might switch straight to hot (vacuum or elec. actuator motor)
or it might blow cold on low, and med, but high might shove door to heater core side (vac or blender door rod)
that motor is expensive, and I do not know many dealers wanting to take back electric components, so make sure it isn't vacuum or the door rod broken first.

[indyhog]

Thanks for your input, I think you guys may be right about the blend door motor not working anymore and stuck in the hot postion.

I spent saturday taking the dash completly out and found this small black servo motor box that set on top of the heater box. There were some position indicating marks on the box and shaft which were aligned to one side. What I belive to be the hot postion, so I just jabbed a screw drive into the top of the shaft just to turn it a little bit. Put the dash back on the the air is not blowing so hot anymore, but the same temp at any setting.

How do you take the heater box out so that this motor can be replaced?

BTW- How do you take off the whole windshield arm from the post. Mine seem to be stuck, is there a tool?

[glathrop]

There should be two screws that hold that servo motor on the box
and unplug it and it will came right off.

[indyhog]

Three screws, One is on the back side of the motor. I could not get to it with out pulling the whole heater box forward a little, but don't know how. Where are the bolts located to pull the heater box?

[glathrop]

I got some info it seems to get to and pull the heater box.
Are you ready for this? You have to pull the right front fender and
inter fender. All of the electronic componts have to come off the fender
The ac has to be evacuated. And then you should be able to get to
the bolts that are for the heater box. Quite a job thats way i have not
replaced my heater core yet. Most places want between 800.00 and
1200.00 to do the job. Their book says 8 to 10 hours in a shop.
If you do take it all apart make sure you replace the heater core.
It is inside the heater box.

George

[glathrop]

Me again forgot the screw on the back side of the servo is not a screw
i worked on mine for a long time until i just took the two front
screws out and it came right off.

[BrownBravada]

Indyhog just wondering if you have solved this problem mine just started doing the same thing. i have a 98.

[ericn1300]

Originally Posted by BrownBravada

Indyhog just wondering if you have solved this problem mine just started doing the same thing. i have a 98.

you need AC in Wisconsin in November? Global warming must be true

[indyhog]

Originally Posted by BrownBravada

Indyhog just wondering if you have solved this problem mine just started doing the same thing. i have a 98.

BB,

I have not fixed this problem yet, but I do agree with glathrop that the problem is the Climate control motor on top the heater box. I have been wanting to just go to a junk yard to get a new one...no free time.

Are you thinking about attempting to fix this you self? I competely understand wanting to fix this even with winter in sight. No mater how cold it is outside the heat on the inside is unbareable! Mine broke in August...DAMN HOT!

[indyhog]

Success!


Last weekend I replace the actuator for the blend door motor and I have hot and cold now! Taking the dash out is a heck of a lot easier the second time. It is some much easier to take the dash with the steering column dropped down 2", and that is even simple. Just remove the 4 M10 nuts from large black boat hull shaped bracket under the column and the two M15 nuts from the column attachment points to the body. You will see them, hard to miss. Also an air ratchet makes the work fast. Don't buy the replacement actuator from the dealership its almost $200. I found an AC-Delco replacement at Rockauto.com for under $120 with shipping and had it with in 2 days by standard ground. The GM part number for the actuator is 89018365 and the AC-Delco part number is 1572971. I believe this was a fair common part for many of the GM cars and trucks with this same climate control unit.

Rockauto.com is defiantly worth checking out when looking parts at good prices.


Good luck!

[blazee]

I'm glad to hear that you got it fixed.

This thread may help people reading this in the future:
http://www.automotiveforums.com/vbul...d.php?t=503195

[boldsmobile]

Had the same problem with my 98. I was able to get the blend motor out by just taking out the glove box. Two screws and one support boss hold it there. I used a 1/4 drive socket with a special ratchet wheel from snap on. Its a fine tooth ratchet head with no handle and the ege is knurled you can grip and spin it.

What i found in mine was that during one horrendously cold day a gear inside cracked. Sleeved the recess faced of the gear with an aluminum collar so the split in the gear would stay closed. Still working luckily.

Those things make some big torque !!!

Anyone else get this prob, check out the gear first to see if its cracked. You might find a way to fix the gear.