ok i have a 1998 blazer lt 4wd with ecc heat and a/c. the blower stopped working then would work for a lil bit, well i have a 19 month baby that rides in the blazer and not having a working blower just isnt going to work so when i pulled the trans to be rebuilt i pulled that crappy blower out and changed it and the black box attached to it and i still dont have any heat or fan working. the rest of the controlls work just no blower. help as to what to look for or try thanks. a noob blazer owner fixing these bugs.

 

So it wasn't working before you replaced the blower motor and still isn't working now.

The 'black box' that you state has been replaced, where is this located?

Here is the diagnostic chart for your condition:

 

it was working then it went to interminttly and then stopped all together. the lil black box was to the left of the blower. it says itt automotive on it if i recall right. i have tryed to locate the part online and other places with no luck.

 

Blower motor control module most likely.

You may have a break in the PWM signal wire from the ECC module or possibly just a bad ground to the blower motor control module. G117 serves as the ground for both the blower control module and the blower motor. I believe this ground is located over near the brake booster on the firewall. There should be a black wire that comes out of the harness and has a ground lug on the end of it bolted to the firewall.

 

holy cow batman thats alot for for me but ill take a look and see if the ground may be bad the connectors looked good to me nothing bad. the pwm signal wire where would i find that or a color of the wire so i can try to find that?

 

Check out the schematic I posted above.

 

im thinking that the blower controller is bad. is that the ecc module you are talking about? if so i priced one from the dealer and they want 500.00 for a new one.ouch

 

The ECC is the part that has the controls on it. There is also another component that the ECC interfaces with that controls vacuum to the various door actuators, but I doubt that has anything to do with your problem.

Did you go through the diagnostic I provided?

 

yea i tried to go thru as much as i could but with no garage to use its been hard to go thru everything.