Buick century high blowers wont turn off, not the relay?

Maintenance/Repairs
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1

1997 buick century.

recently, my ac high blowers stopped being able to turn off. with the car running, i could turn it up and down, but when i turned it off, it would turn on the high blowers. i managed to identify the relay responsible and, when removed, the blowers would stop. but…everything relating to heating/cooling the cabin would stop. when i put in a new relay, the problem would start again, so its not the relay.

the display for the control hasnt worked since i bought the vehicle. i can still use push the up/down to change/control the temperature, but no display lights have ever worked.

im a total noob with electrical stuff, anything helps!!

2

Are you referring to the blower motor under the dash that blows the air (hot cold whatever) on you, the floor and or the windshield??
Or are you referring to the radiator/AC condenser fans??
You have one blower motor (no s) and two radiator fan motors, so saying blowers with a s means two or more… Just trying to make sure we are on the same page…

3

If the HVAC control module display isn’t working, then that means there’s a problem with the module.

So, that needs to be replaced to make sure all components in the HVAC system are working correctly to find the actual problem.

Tester

5

thanks, tester. im a little puzzled b/c it has been now seven years with the display not functioning with no other apparent issues stemming from it, but it does seem as good a start…i found another thread since posting this that identifies the “blower control module” as being a problem - is this referring to the same thing as “HVAC control module” ?

6

thanks davesmopar, i mean the first, radiator/ac blower that controls the climate, defrosts, all that. the relay i pulled that stopped the high ac motor from going is labelled “high blower” (singular) on the fuse box diagram.

7

HVAC means Heating, Ventilation, and Air Conditioning, and all components in that system.

Electronic components can fail instantly, or go thru a slow death.

You can’t fix a system if you don’t first fix what you know is broken in the system.

Tester

1 Like
8

Relays can weld themselves closed… try swapping an exact copy from one nearby.

2 Likes
9

I agree and would try that first.

But as I was reading your initial post I was thinking that your HVAC control head was messed up - as Tester mentioned.

10

That’s what I would have replaced and did. I paid about $25 at the junkyard. My blower would continue running with the car shut offf. I just pulled the fuse. Don’t know what you replaced or the other problems but that was my issue.

11

It sounds like a faulty control module to me. It should be possible to verify that’s the problem before replacing it, but it seems like the consensus here from the experienced folk is the module is almost certainly the problem so save the expense of testing and just replace it. I’m not keen on that idea and if I had this problem myself I’d probably do the necessary testing to prove it is a faulty module first. If you do decide to replace the module, suggest to retain possession of the currently installed one.