eldridge201

I worked as a Ford technician for about 6 years roughly 20 years ago but I'm not as familiar with Chevrolet vehicles so I'm hoping you guys can help me out here.

Got a friend that has a 2017 Chevrolet Trax and the blower was only working on the high setting so with my experience, I immediately assumed the blower motor resistor was bad so I got one from O'Reilly Auto parts and switched it and installed it and everything seemed to be fine until they got a hold of me a couple weeks later and said that the blower was not working on any settings so I switched out the resistor again.

After a couple more weeks, they got a hold of me and informed me that it was not working again unfortunately. Once again, for the second time, I switched out the resistor and I believed that it was working correctly on all settings so I thought all was good.

I typed "I believed" it was working on all settings because I may have actually not verified that it was working on the first setting and I will explain that in a second.

The client contacted me about 2 or 3 weeks later roughly and explained to me that the blower motor was not working at all. Fortunately, we saved their original resistor which at least was working on the high setting so we switched it out until we could get a replacement from O'Reilly's but the client informed me that they did not believe that the blower motor was working on the very first setting after I changed the 2nd resistor out. I thought that I had verified that but it is possible I did not so that may be a potential indication of what is going on here.

Anyway, I switched out the resistor for a 3rd new resistor from O'Reilly's and verified that everything was working this time and it was working on all the settings so I thought everything was good to go.

Unfortunately, the client contacted me another 2 weeks later (a couple days ago) roughly and informed me that the blower was only working on the second and third setting and not the first or fourth setting. When I got the client to bring me the vehicle, I actually verified that it worked on all settings except for the highest setting or the fourth setting.

Upon examining the wiring as well as the connectors at the resistor and the blower motor, the wiring and connectors looked perfect without any indications of any slight burning so there was no light tan or light brown coloring at all and the wires did not appear to be hard or brittle like what normally happens at the blower motor resistor or the blower motor itself so I did not think that there was any indication that the blower motor was having any issues.

However, the wiring and connectors were only fine for the first three times of switching out the resistor. The last time, unfortunately, the connector at the resistor has now gotten melted a little bit and burnt at a couple pins so it needs to be replaced as it is now bad.

The blower motor did not make any noises such as any squealing or clicking so I did not presume that the blower motor itself would have any issues that would be causing this problem but of course that is obviously a potential issue.

Since this is the third replacement part that we have switched out, O'Reilly's is not willing to do another replacement so I am trying to figure out what is going on here. I know that we are supposed to figure out what is causing a part to go out but since I thought everything was working fine after the first replacement, I assumed everything was okay but then after it went out only a few weeks later, I got suspicious however, since parts do fail and are defective, I figured potentially it was a fluke issue so that's why I got a second replacement part from O'Reilly's.

Obviously, replacing it after the second time is a major cause for concern that it is probably not the part since it is highly unlikely that you're going to have three defective parts in a row but I have heard of some really odd situations from people having issues with parts and I myself have had to replace multiple defective parts just because the parts themselves were not manufactured properly.

Obviously, I'm aware that there could be a number of things going on from the blower motor itself to the HVAC control module as well or potentially a relay but just wondering if somebody could give me some direction in this area?

I called a couple dealerships and one of them informed me that they did end up switching out a resistor and blower motor twice but after the resistor went out a third time, they finally figured out that it was an HVAC control module or head unit.

I'm not sure if I should lean that direction or not as my experience tells me that normally it is a blower motor that causes the resistor to go out but without any sort of noises or anything to indicate that there are problems with the blower motor, I don't know if that's the way I should go.

Can anyone give me the specs that the voltage is should be at the blower motor when on the different settings or what the voltages should be at the blower motor resistor when I have it on each setting at the control unit? If so, obviously I can check that with a multimeter.

Otherwise, if somebody has experience with this and could just tell me that it is likely a blower motor or the HVAC control unit itself, I can switch those out easily enough.

I know it sounds like I just threw parts at it by just changing the blower motor resistor three times but in spite of that, I don't typically like throwing parts at things but since I was able to replace it under warranty each time, that wasn't a big deal. I haven't sat down and did any testing really because I don't have the information regarding what the specs need to be.

So, that's why I'm here. I apologize for the extremely long post as it's my first I apologize for the extremely long post.

Thanks to anyone that made it this far and read it and for anyone that can offer me any help.

jfmorris

When blower motors start going bad, they pull more current, and could potentially lead to burning up the resistor or the wiring harness. All current flows through the resistor packs, and the lower speeds have more of a drop across them, and probably get hotter. In high speed, the current is flowing through the blower relay, bypassing all the resistors in the pack.

I would be tempted to replace the blower motor even if it works, as *something* is causing the resistor to burn up...

Just my 2 cents, having replaced blowers and resistors on Chevy trucks that I owned over the past 24 years.