Heat (Intermittent) Problems

[tonypass]

I have already searched previous posts. Please help I am at my wits-end.
At times my heater won't come on. I have taken out the Control on the dash, replaced it and rebuilt it cleaning contacts and grease. I have had the blower out twice and bench tasted it.

One day I slammed my door and miraculously it came on. So now when the heat doesn't respond I slam the door and it usually turns on. My question is

Is There a connection for the HVAC control in the drivers side panel or perhaps in the fuse panel on that side. It seems that something is making partial contact. Thanks in advance Tony

[fdryer]

Thank you for the BOLD request for help but your request will go unanswered...............because you haven't provided any car info. Year, model, engine size, and some car history goes a long way to painting a picture of what you're having problems with. And if you can, update your profile so car info pops up under your name, negating having to repeat car info every time an enquiry is made (unless its about a different car).

Your descriptions of symptoms seems scattered and not pointing to a specific problem. Is this about the lack of blower operation or a lack of temperature control? Since you haven't posted car info, the hvac control panel is either completely computer controlled (one description is auto climate control) or manual. Which one?

If this is a Saturn, every model made has 100% coolant circulating all the time. The temperature door allows mixing incoming air to flow thru the heater core to modulate cabin temperature from 100% outside air to full conditioned air thru the heater core. Your hvac control head uses either a dial to computer select desired temperature with digital display or manually controlled dial/lever to select zero to maximum heat.

[tonypass]

(The bold was only an expression of frustration.) I own a 2001 LW200 4cylinder. The problem is the blower it doesn't always switch on when I want it to. There is a loose connection someplace, I have cleaned (and replaced) the HVAC control panel. I also removed the blower and bench tested it. As I stated the blower if it doesn't switch on as requested, will come on if I slam the drivers side door. Once on it heats and changes speeds just fine.
Thanks for your reponse.

[born again]

OP still hasn't identified his climate control, manual or automatic. A few random causes could be worn brushes in the fan motor (can be intermittent), the speed control resistor card, wiring or grounding.

[fdryer]

tonypass, did you examine the blower motor connections? There are instances where either the power of ground wire is burned, causing intermittent connections. You may have to fish around for the wiring harness to see where the cooked wiring goes. You can also try measuring for voltage to see if power is getting to the blower and connect a separate ground wire to the chassis. A 12v test light can be used too without a multimeter.

[pierrot]

An application check at gmpartscenter.net showed that the unit should be a manual HVAC control, there was no other option listed. I compared his model year to my own. My car has the manual control and utilizes the same part number as the '01 LW200.

[02L200MrJ]

I'm leaning towards a bad blower motor.
Few weeks ago when changing the BCM I waited to button up the glove box until after the 30 minute marrying cycle just in case.

Anyhow, it was getting cold so I let the engine run as I reinstalled the glove box, while trying to realign everything and that short piece of ducting that secures under the glove box I was moving around a section of wiring harness that obviously ran thru the firewall to the blower motor. Some times it would cut out or on, some times the speed would change slightly. We had bought a new motor before the BCM went belly up but hadn't had the chance to replace it.
Our symptoms...ran when it wanted to, some times when not running would start up on left hand turns. Sounds like bad contacts in the motor, OK bought a new motor.

But now I started thinking it was a burnt/bad ground. Crap, $100 for a motor that wasn't needed.
Anyhow, couple days later after having the BCM reprogrammed at a shop I got around to working on the blower problem. To verify it was a bad blower and not the cars wires/ground, after I got to the motor but before removing it I reached under the motor and wiggled the wires right at the plug. Sure enough the motor cut on/off intermittently. Obviously the problem was bad/worn contacts inside the motor that wiggling the wires was enough to make good contact at times.
And again to check that, after the new motor was in I wiggled the wires the same way, there was no cutting on/off anymore.

Your door slamming was like my left turns and wire wiggling and caused a temporary good connection.
Of course there still is the possibility of a bad ground in your case.