[louisanak1500]

hey i have a 1998 k1500 with a 5.7. my blower motor wont work on high. works on the other speeds and blows strong. ive replaced the resistor, the high speed relay, the blower motor it self and the speed switch on the control panel. dont know what else to do. Please help.

 

[kennythewelder]

Welcome to the forum, from a fellow member from Lafayette La. Its almost always the resistor on the top of HVAC box, but you say that youve replaced it. Next step is to use a VOM multi meter and see that you have current to the wire supplying the blower on all speeds. Then check it at the resistor. You could have a defective resistor. Its going to take some tracing down to find your issue.

 

[louisanak1500]

Welcome to the forum, from a fellow member from Lafayette La. Its almost always the resistor on the top of HVAC box, but you say that youve replaced it. Next step is to ise a VOM meter and see that you have current to the wire supplying the blower on all speeds. Then check it at the resistor. You could have a defective resistor. Its going to take some tracing down to find your issue.

Ive heard that the resistor only controls the other speeds the relay controls the high speed?

 

[kennythewelder]

Not 100 percent sure, I just know that mine was only working on 1 speed. After I replaced the resistor, I got back all my speeds. Then the blower motor started making noise. After replacing that, the air flow improved a ton from the vents.

 

[louisanak1500]

yeah im thinking its a wiring issue gotta be

 

[kennythewelder]

Do you have a shop manual? It will have wiring digrams to help you trace down whats what.

 

[kennythewelder]

I swapped out the HVAC control unit in the dash a little while back. I am not impressed with the new unit, but it is an ebay one. Im having AC issues. Found the compressor is leaking, but even of a full charge, the only way to get the compressor to come on, is to jump the relay. I have no time rite now to work on it. Like you, i need to trace wires. Also I need to replace the compressor. Ot works for about a week and a half, so I will add freon untill I have the time to fix it.

 

[louisanak1500]

Update found my issue. The dang blower motor fuse. Figured hey the blower motor is working so the fuse should be good. Nope it was blown so if yalls blower motor ain't working on high its the fuse

 

[RayVoy]

Update found my issue. The dang blower motor fuse. Figured hey the blower motor is working so the fuse should be good. Nope it was blown so if yalls blower motor ain't working on high its the fuse

Sorry louis, wish I had signed on here a few days ago, might have saved you a little frustration. You have 2 fuses, one for high speed and one for all others