Frogger2662 Posted February 29 Author Share Posted February 29 https://forum.garysgaragemahal.com/Next-issue-Heater-air-flow-tp145358.html The truck came with a/c and heat. It has controls for both still in the cab. Even have the original pigtails cut off short. If I use just the heater for now can I wire it like the top diagram without any of the a/c wiring? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 1 Share Posted March 1 The truck came with a/c and heat. It has controls for both still in the cab. Even have the original pigtails cut off short. If I use just the heater for now can I wire it like the top diagram without any of the a/c wiring? I posted both of them so you could see what you're up against. I'm going to say, look at the AC model and notice "off" position , while all blower speeds are on the right. If you have AC, you probably want to use the left switch to control the relay and the right to deal with speeds. I believe the AC switch is piggybacked. Be careful which row of contacts you make live. I hate when people hack stuff before they understand how it works.... Link to comment Share on other sites More sharing options...
Frogger2662 Posted March 1 Author Share Posted March 1 I posted both of them so you could see what you're up against. I'm going to say, look at the AC model and notice "off" position , while all blower speeds are on the right. If you have AC, you probably want to use the left switch to control the relay and the right to deal with speeds. I believe the AC switch is piggybacked. Be careful which row of contacts you make live. I hate when people hack stuff before they understand how it works.... I think I have most of it figured out. Going to use the a/c heater combo switch. Two more questons. On the blower resistor there is 3 prongs grouped together and 1 seperate. The 3 together are high,medium and low. Which is which? On the a/c-heater function switch can I leave out this leg of the circuit. It appears to me to be for the clutch which I do not have. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 1 Share Posted March 1 I think I have most of it figured out. Going to use the a/c heater combo switch. Two more questons. On the blower resistor there is 3 prongs grouped together and 1 seperate. The 3 together are high,medium and low. Which is which? On the a/c-heater function switch can I leave out this leg of the circuit. It appears to me to be for the clutch which I do not have. Correct. Note that left and right are the same control, just that it is stacked, with two rows of contacts..... So (for now) you only need to power the right hand one in the illustration. If you look at the blower resistor you'll note a thermal fuse. Be certain you have continuity through the resistor block before you pull your hair out. AC and heat only trucks (like mine) have different configurations If you can't match the colours shown in the diagram, I'm going to suggest you just ohm out the pins to determine which of the three is what speed. Link to comment Share on other sites More sharing options...
Frogger2662 Posted March 1 Author Share Posted March 1 Correct. Note that left and right are the same control, just that it is stacked, with two rows of contacts..... So (for now) you only need to power the right hand one in the illustration. If you look at the blower resistor you'll note a thermal fuse. Be certain you have continuity through the resistor block before you pull your hair out. AC and heat only trucks (like mine) have different configurations If you can't match the colours shown in the diagram, I'm going to suggest you just ohm out the pins to determine which of the three is what speed. Still fairly new to this level of electrical work. Can you tell me exactly what to look for when I perform the ohm check? I can follow instructions pretty well. Thanks Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 1 Share Posted March 1 Still fairly new to this level of electrical work. Can you tell me exactly what to look for when I perform the ohm check? I can follow instructions pretty well. Thanks Look at the picture. Orange/black is high and power in. Lt Blue/orange is medium Red/orange is low. Blk is ground, as is the case throughout the truck's harness. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted March 1 Share Posted March 1 Still fairly new to this level of electrical work. Can you tell me exactly what to look for when I perform the ohm check? I can follow instructions pretty well. Thanks You need to check the ohms between the orange/black (common) terminal and the other 3 blades. Link to comment Share on other sites More sharing options...
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