Greetings all,

i recently acquired a silverado 2500hd,
me being OCD, i took out all the chairs and carpet and cleaned everything.
dash was removed to be fixed because it was cracked.
speakers did not work so i replaced them.

of course, i did not unplug the batteries.

Speakers work great,

BUT now, air won’t blow.

i checked blowing motor, resistor and they are functional.

at blowing motor connection, it measures 12v (14.4 when engine on)

seems to have power but motor won’t blow at all.

has anyone ever had this problem?

my brother in law has a gmc 2500hd, he replaced his stereo and now has the same problem.

i tried my best to test continuity and fuses… everything seems ok,


but no air.

any info would be greatly appreciated.

thx for reading.

 

Here are some pics. I just noticed that multimeter shows ~12v with or without ignition key on

 

what about ground? Does it have a good low resistance path to the chassis?

 

mmmmm,
not sure, i am not very knowledgeable,

Red, black and small wire going to resistor has continuity from wire box on right side of passenger dash.
i was to understand that small white and purple wire is signal wire.

i did also use a test light.
battery negative with wire=green
battery positive with wire=red

not sure if that answers the ground question?

i could try with step by step advice.

thank you for your time.

i am just confused as to why it’s not working knowing there is voltage.
btw, blowing motor was hooked directly to battery and is turning.

 

voltage is not enough. You need positive and negative (ground in this case) in a closed loop to make complete circuit.

 

You didn't post you model year so I don't know what I'm dealing with.
But if you go to charm.li you will find the wiring diagram for your blower there. Post it and we can help you trace the problem.

 

Thank you, will check that later

 

Waooo,
just took a quick look at charm.li, huge information base.
thank you so much, will check on it and update .

sorry i forgot about the specifics

2008 chevy silverado 2500hd, 2wd, v8, 6.6l.

 

Good day all,

looked over the web site.

Only diagram for blowing motor is explanation and details of the connector.

purple is battery positive voltage
black is ground.

tests i did today:
resistor wires are continuous (no short) from side of door, please refer to pic 1
Battery was unplugged.

Trying to answer the ground question from mountainmanjoe,

i have: battery and blowing motor connector:

- measure battery + to blower negative =11.8v
- measure battery - to blower += 11.9v

i also tried blower + to a grounded screw =11.9v