Blower fan control wiring

[TJones]

I just got a new heater switch and pigtail for the blower fan connector from lmc. I see the yellow blue and orange in the wiring diagram but the pig tail has different colors and 4 instead of 3 wires. Can anyone help me figure out which wires form the new pig tail connect to the each of the 3 wires form the factory harness?

 

[PrairieDrifter]

You got the wrong ones if it doesn't match your wiring. Its a 70 vs 80'e thing and an a/c vs non a/c thing.

 

[TJones]

You got the wrong ones if it doesn't match your wiring. It’s a 70 vs 80'e thing and an a/c vs non a/c thing.

gotcha. I ordered what looks like should have been for the truck according to lmc. I ordered for a 1983 non a/c. Is there a different one I should have ordered?

 

[PrairieDrifter]

gotcha. I ordered what looks like should have been for the truck according to lmc. I ordered for a 1983 non a/c. Is there a different one I should have ordered?

Are you positive that's what you have? Could be a different harness or year. 83-84 was a transition year.

 

[TJones]

Are you positive that's what you have? Could be a different harness or year. 83-84 was a transition year.

I verified the truck is a 1983 gmc k2500 diesel with no a/c. I called lmc and they checked their database and said that should be the correct set up

 

[Ricko1966]

I verified the truck is a 1983 gmc k2500 diesel with no a/c. I called lmc and they checked their database and said that should be the correct set up

Is your old switch totally smoked? If not you should be able to use an ohm meter and check resistance on the wires in different positions.Then do the same to the new switch,noting which wires have same values in the same positions,hook the new switch up accordingly. As a matter of fact just check resistance on the old switch in different positions anyway to verify if your old switch is good or bad.