I guess I'll chime in with my heat problem now. I've had this issue for a few years now and am out of ideas. I have a 1997 Olds Bravada with 143K miles, and here's what I've done so far:

1) Thermostat replaced. 195 installed. Verified operation in pan of hot water before installation.
2) Heater core and heater hoses were replaced when heater core started to leak.
3) Both heater hoses get hot.
4) Blend door works correctly.
5) Fan clutch replaced (it was stuck on).
6) Water temp only at 177 even after driving for 10 minutes or idling for 15 minutes @ 40 degrees outside temp. Used laptop to read PCM. Dash gauge shows about the same temp.
7) Coolant is full.
8) Flushed heater core. Water was clear and full flow in both directions.
9) Upper rad hose is getting hot - not sure why if water temp is only 177. Therm shouldn't be open yet.
10) Small amount of heat coming from rad fan. Again - if water temp is only 177, therm shouldn't be open yet.
11) Heat at vents is only 105 degrees.
12) The only time that I've seen the temp gauge go to 210 is when it was about 80 degrees outside. Then I have a decent amount of heat.

Anyone? I'm stumped and out of things to try.

Thanks,
Tim

 

Is 105' F at the air outlets not considered hot?

 

Not really. According to the service manual, here are the minimum acceptable heater air temperatures at various outside air temperatures:

Vent | Outside
temp | temp
130 - > 0
139 -> 25
147 -> 50
155 -> 75

 

How is the air flow though the vents?

I ask as when I was replacing my blower motor I had found about 6 good handfuls of tamarack needles and ash leaves plugging the AC condenser, up stream from the heater core. This was in addition to those needles I got with the shop vac.

My '99 that has the climate-control (auto temperature control system). Part of that system is a Blower Motor Control Module thermal sensor that has a large heat dissipation surface. I think this module did not work properly due to the presence of the needles insulating the heat dissipation surface, fooling my temperature control system.

Might this be the problem? It is something that happened to me very gradually, so slow I had not noticed the diminished air-flow. I thought I had been good at cleaning out these needles but I had had no idea they had gotten so far into the system.


needles packed in on the upstream side of the AC condenser by behind where the Blower Motor Control Module mounts


Some of the needles I removed.


inside surface of a Blower Motor Control Module

 

The air flow through the vents is meh to adequate. It's not outstanding. I attributed this to a bad design.

I have the manual temperature control, and all 4 blower motor speeds work.

The pictures that you have included look different than my 97. Removal of my blower motor requires cutting the plastic housing (which is starting to get very brittle). Also my resister pack is on the other side of the evaporator.

Perhaps I should cut a hole in the area where your resister pack is located (after the blower and before the evaporator) and look for debris?

 

On mine, where your blower motor resistors are located, I have a simple access panel that can be removed by first cutting through the outer rubber layer. (A previous owner once removed the panel for some unknown reason.) This is where the resistors for the manual motor control would have been located, just like yours. Perhaps yours has a similarly unused access panel where a blower motor control module like on mine would have gone? If not, to do the check for debris you would have to remove the blower motor.

I looked at Rockauto and for your year (1997) there is no solid state control module which suggests that there might not be an access panel where it might go. However, it is always really easy to take a look.

It is not hard to pull the motor, just really annoying at all of the stuff you have to first get out of the way to replace it.

Regarding the motor removal, yes you have to cut the rubber over-layer. When I replaced the blower motor, I sealed it back up with some black rubber compound, per the instructions. If you use RTV, use a type that is non-corrosive. The original RTV silicone formula releases corrosive gases as it cures which would be bad for any electrical connections. There are plenty of youtube videos that you can watch to get a feel for what is involved. If you do remove the motor, be careful of not cutting the motor drain tube. I had purchased a replacement tube so I was not very careful of it but the replacement tube was not long enough so I had to fix the tube with some Rescue-Tape (self-fusing tape).

Finally, for your case with the manual blower motor control, the only effect of a blocked AC condenser would be reduced air flow. Even on my system the control module's primary job is to control the blower motor speed, not the temperature. Then again, maybe a blockage could affect what is going on. If it is easy to check, you might try.