My heater-A/C blower was not working so I changed out the resistor and relay. Before I changed them the Blazer started fine. Once I did, I turn the key to start and nothing except after holding the key in the start position for about 3 seconds, I hear something engage. I believe it to be the starter solenoid. I feel like an idiot because I did not unhook the battery when I changed the resistor and relay out. Everything else electrical does work except for the blower motor yet but still it will not start. Any suggestions would be appreciated and Thank you in advance.

 

On the firewall there is a black distribution block. Make sure everything is clean and connected.

 

All the connections are clean and tight on the distribution block. Any other ideas?

 

Either charge the battery or give it a jump and try starting it.

 

It ended up being extreme corrosin on the battery cable connections inside the battery. I am not searching why my heater blower motor will not work after I changed the relay and resistor. I just got a test light and am now going to test all the wiring. Thanks all.

 

Usually even if that resistor is fried your blower motor will work just on high only. Get a test light and see if you have power going to the resistor. Also try running a 12v wire to the blower motot to see if it works

 

The reason the blower will work on high is because it taps a different fuse than on low or M1 or M2. Been there, done that. Someone had a bad connection on mine across the black connector (can't remember the number) next to the resistor block and jumped around ot with too small of wire. I replaced the wire with the correct size and it works OK but I'm going to replace the connector soon. It's the purple wire that leads to the blower motor. Does your blower work if you hook up a jumper wire (fused of course) directly from the battery?