G3500 van. No power to blower motor

VINTSHAVE

MEMBER
1993 GMC
5.7L
V8
2WD
AUTOMATIC

Hi,

This problem is really driving me crazy. My blower motor doesn't work. It used to. I replaced the moter, replaced the resistor that the blower motor plugs into. If I jump the center wire that plugs into the resistor to the battery, everything works fine, so the center wire going into the resistor isn't getting current. I can't figure out where this wire is coming from. Fuses are all good.

Please help.

John

5 Replies

HMAC300

MECHANIC
48,601 POSTS

Check your blower motor relay that may be bad. It's on the evaporator case in engine compt

Was this

answer

helpful?

Yes

No

Saturday, November 8th, 2014 AT 10:22 AM

VINTSHAVE

MEMBER
62 POSTS

Sorry, I made a typo. It was the relay I replaced. Didn't work.

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

Saturday, November 8th, 2014 AT 10:26 AM

VINTSHAVE

MEMBER
62 POSTS

There is no power going into the relay

Was this

answer

helpful?

Yes

No

Saturday, November 8th, 2014 AT 10:27 AM

HMAC300

MECHANIC
48,601 POSTS

The relay will only have power on high so check to see if power is going to switch itself and resistor which should be on evap hsg as well. That controls lower speeds. Then check for a burnt fusible link on junction block under hood that supplies power to blower see pic

Image (Click to make bigger)

Was this

answer

helpful?

Yes

No

Saturday, November 8th, 2014 AT 11:52 AM

VINTSHAVE

MEMBER
62 POSTS

I VERY much appreciate your help on this! I figured it out. The clue was the orange wire not getting power. I traced it through the firewall and back to the rear of the ac/heat controls. When I popped it out of the dash I found that when I pushed the plug behind the blower control to the right, it went on. So I used a mechanic's best friend - tape - to hold it in that direction until I can get to a junkyard and replace the thing :

P Time does nasty things to plastic.