Blower fan/relay

[84chevguy]

I have an 84 gmc k2500 I bought it a year ago and the heater never worked. Fan does not kick on at all. I've bought and installed the following.
Relay
Blower motor
Resistor
I regrounded the relay to the alternator. For some reason every time I turn the key to the on position the fuse 25a keeps popping near the pedal. I looked around near the firewall to see if there was maybe an exposed wire of some kind and found nothing.

Before when I figured it was the relay I took the metal too off it and connected the two points together and the fan kicked on without the key being on I believe. I get power into my relay which is weird but no power coming out of my purple wire into the blower motor even with the new relay...... I'm stuck in a rut. If anyone could please help me out I would appreciate it a lot!!!

 

[smoothandlow84]

Does the blower fan spin freely? Maybe the fan bearings are shot and its locked up. If you blowing a fuse, its definately a short somewhere. Could also be a bad switch or connection behind the switch

 

[84chevguy]

Does the blower fan spin freely? Maybe the fan bearings are shot and its locked up. If you blowing a fuse, its definately a short somewhere. Could also be a bad switch or connection behind the switch

It's a brand new blower motor. When I forcefully powered it on it sounded fine. Just don't understand why I'm blowing a fuse still and no power coming out of my purple wire to my blower fan motor from relay when I have good power running through my red wire in the relay. Not sure how I'm getting any power at all with my red if my fuse is now dead.

 

[ffgig]

I had a problem with my 84 blower fan and a 2nd new ignition switch solved my problem. The first ignition switch I installed worked for a few months and then I started having blower problems. First switch was from O'Reilly second one I bought at Napa.

 

[84chevguy]

Your fuse kept popping?

 

[89Suburban]

In ever heard of a relay in the blower circuit on these trucks.

 

[sfish]

I have an 84 gmc k2500 I bought it a year ago and the heater never worked. Fan does not kick on at all. I've bought and installed the following.
Relay
Blower motor
Resistor
I regrounded the relay to the alternator. For some reason every time I turn the key to the on position the fuse 25a keeps popping near the pedal. I looked around near the firewall to see if there was maybe an exposed wire of some kind and found nothing.

Before when I figured it was the relay I took the metal too off it and connected the two points together and the fan kicked on without the key being on I believe. I get power into my relay which is weird but no power coming out of my purple wire into the blower motor even with the new relay...... I'm stuck in a rut. If anyone could please help me out I would appreciate it a lot!!!

where is your relay located . I can't find it on my 84 gmc

 

[Wallace6]

I am having a similar problem,my blower motor worked fine a few days ago,no weird noises or anything and now nothing. I can hear the switch select modes, def,heat and so on. Checked the 2 fuses(rear ac) both were good.
is there a relay to control the front blower motor?

 

[75gmck25]

If you have A/C there is a blower motor relay mounted on the A/C plenum under the hood. I’m not sure of the setup on a non-A/C truck.

On my ‘75 there is also a blower resistor pack/assembly on the plenum. The resistors are used for lower speeds, and high speed is a direct 12 volts.

 

[Wallace6]

I don't think my problem is the resistor, I get no speeds. It was working fine ,no sound and than just quit. Fuse looks fine. Any ideas? Thanks

 

[PrairieDrifter]

I don't think my problem is the resistor, I get no speeds. It was working fine ,no sound and than just quit. Fuse looks fine. Any ideas? Thanks

High speed goes through a relay, the other three go through the resistor block.

 

[Wallace6]

So the relay like pictured above? On the a/c box? Thanks

 

[Wallace6]

Any idea what would cause the blower motor to quit working suddenly?

 

[PrairieDrifter]

Ground or power loss. Or blower motor just said it was done. It happens with anything electrical.

 

[Ricko1966]

If you can close a relay and the fan works that eliminates power to the fan it also elimates the fan,the fan bearings,the fan ground etc. It's the relay itself or on the signal side of the relay. The relay takes battery power in and when the relay closes it turns on the fan. The relay is not closing on its own. 2 wires of the relay 1 is 12v in and one is 12v out to fan when closed the other 2 close the relay 1 is ground 1 is switched power when switched power hits the relay an electromagnet pulls the points in the relay closed which supply voltage throigh the points to the blower.