Hey guys,
I have a '98 C5 and since the day I bought it the air (warm or cold) hasn't worked right. At first it would turn on and off at random times and then eventually it just stopped working all together. It has the removable glass top so I never really cared that the air didn't work cause I'd stay cool in the summer from the breeze. It's getting colder though so I called an auto parts store and bought a used climate control unit assuming mine was broken. When I put the new one in the lights didn't work so I checked the fuse by the passengers feet and it was blown. I replaced it and the lights turned on. I figured at this point I was good to go but the blower/fan still won't turn on I thought I'd try my old climate control unit thinking maybe I was a moron and it was the fuse all along, but the old one didn't get the fan to turn on either. So what do you guys think? Could I have 2 bad climate control units or is there something else I should be checking? Is there a chance my blower motor is bad or something? How would I know?

Thanks!

 

If you have auto climate control theres a logic module mounted on the bottom of the air box in the passengers foot well:





The Manual HVAC system has resistors on a board for the fan apeed control lke this:



The Auto control is different and th speed is controlled by digital circuits.

Bill

 

Thanks Bill!!!

How do I know which one I have?

If it helps, I don't have the digital display climate control unit with the LCD screen. All mine has is 3 dials I can turn (fan speed, temp from red to blue, and the dial that indicates which vent the air will come from)

 

Haaaaaaaaaa!! Your wallet will appreciate that! You have the one pictured with the burn marks on the board. That one is a TON less money that the digital one!

If yours is burnt up and you get a new one, can you send me the old one??? I want to expirement with it.

BC

 

Bill, this isn't the first time you've helped me out on these boards. If that turns out to be the problem you can no doubt have my burnt up one to tinker with!

 

Oh!!! Be CAREFUL working on the blower. If you GROUND the motor case, the fan WILL RUN in high speed! Remove the fuse prior to removal!!! ASK me how I know that!

BC

 

To replace it take off the panel at the passenger footwell and look up to see the blower motor. It is difficult to reach due to the awkward angle to get at it. The two screws at the back just need to be loosened NOT REMOVED because the module is slotted at those two screws. Remove the one screw in the front, loosen the back two and pull it out.

 

Well ****!

I spent the day today replacing everything I could think of and nothing fixed it. So far I have replaced the: Blower Motor, Blower Motor Resistor, and the Control unit itself. The maxifuse that controls the blower motor is not blown either. So what the Hell!? Why can't I get this damn thing to work!?!?!


Is there a relay or something in between the control unit on my main console and the blower motor itself? I mean, I've replaced all the working parts so it's gotta be electrical...right? Anyone know where I should start?

 

There are TWO HVAC Fuses:

Instrument Panel Electrical Center
HVAC Mini Fuse#18
BLO MOT Maxi Fuse 49

That goes to the Blower Motor relay . The blower Motor relay is grounded at Splice pack 202 and that is grounded at Chasssis groundd point 202:





Make sure that the switch its self is properly connected and working.

BC

 

Thanks Bill! How exactly do I get to Chasssis groundd point 202?

 

Starting at the lock pillar lift the sill plate unsnapping the clips from the door opening finish trim panel.
Unsnap the sill plate from the hinge pillar.
Slide the sill plate out from under the hinge pillar upper trim, and on the drivers side out from around the hood release handle and the foot rest.

 

Looks to me like it's time to stop throwing parts at it, and do a little troubleshooting. Some times it saves lots of $$$$$$$$$.
------------------------------------------

 

Byron

Thanks for the shcematic!

Simbotto

You have an early C5 98. Your BLO MOT fuse is Maxi fuse# 49 vise the late C5 Fuse # 51

I agree.. Grab a meter and start looking for the basic. Power and ground and then pecific signals.

The front door sill cover just pops up. Its secured with body clips

 

I disagree Byronhunter.....there are plenty more parts to change.....

 

Yelp Lucky, you're right about that, It goes on all the time!

 

Well, I checked the chassis ground point on the passenger side and it looked just fine. Although, while I was at it I decided to pull the one on the driver's side by the headlights and holy crap was it corroded!! Does anyone have a list of common ground chassis packs that tend to corrode more than others?

Also, is splice pack 202 on the drivers or passenger side? If it isn't the grounds is it safe to say it is that relay you were talking about Bill? What do you guys think I'm looking at here? How many more things could it possibly be!?

 

SP 202--------Look at post #9 and 11. That is the Pass Side.

 

The wires that you see going UP into the dash in my G-202 picture have SP-202 taped to it. Just follow those wires UP and you will find the splice pack Doubt it its anything to do with your issue but,, at least you will know where its at and what it looks like. It will look just like this:





What you really need to do is use a meter and trace out the 12 VDC signal. Find that relay and figure out if its working.

BC

 

Thanks guys. On my next day off I'm going to try the meter idea and see if I can figure anything out.



Bill - PM me where you would like the blower motor resistor shipped to.