Blower motor resistor AND connector melted AGAIN !?!?!?!?!?!?!

[767Jockey]

2005 T'Blazer, 6 cylinder, manual A/C controls. Maybe 6 months ago, blower fan speed 5 stopped working, followed by the rest shortly after. Following the great advice on this forum, I checked the blower motor resistor and plug, and replaced as advised. Sure enough, everything worked fine once again. Now, here I am maybe 6 months later, and I have the SAME problem yet again. Fan speed 5 stopped working a week ago, and today the rest of the speeds quit. I pulled the resistor down again, and the connector plug is so melted in there that I can't get the plug connector out of the resistor. One of the center wires is burned and melted about 1/4 inch outsode the plug. By wiggling that wore I can get speeds one through four to work again, but the wore and plug get really hot. I bought the connector and resistor at Auto Zone last time, the one that's in there now. I don't recall what brand they were, I'm 99% certain they were AutoZone's own brand. Could it be bad parts from Auto Zone? Low quality? Is this a known problem with AutoZone brand parts of this type? Any ideas on what would cause this to fail yet again in the exact same way? Is there a better brand or resistor and plug that I should buy? If so where should I buy it?

Thanks in advance for any and all advice you guys may be able to lend.

 

[McGMT]

2005 T'Blazer, 6 cylinder, manual A/C controls. Maybe 6 months ago, blower fan speed 5 stopped working, followed by the rest shortly after. Following the great advice on this forum, I checked the blower motor resistor and plug, and replaced, ad sure enough, everything was fine. Here I am maybe 6 months later, and I have the SAME thing again. Fan speed 5 stopped working a week ago, and today the rest of the speeds quit. I pulled the resistor down again, and it's so melted in there that I can't get the plug connector out of the resistor. I bought the connector and resistor at Auto Zone last time, the one that's in there now. I don't recall what brand they were. Could it be bad parts from Auto Zone? Low quality? Is this a known problem with AutoZone parts of this type? Any ideas on what would cause this to fail yet again in the exact same way? Is there a better brand or resistor and plug that I should buy? If so where should I buy it?

Thanks in advance for any and all advice you guys may be able to lend.

That sounds like a crappy old part from autozone. IIRC they made changes to the resistor to get rid of the harness melt issue. Seems like you may have gotten an old style part. I could be wrong though and the new ones might be melting like the old ones did but I am not 100% on that.

 

[bore_pig]

Change the end on the harness, put in another new resistor, and change the blower motor as well. Blower motors that are starting to go bad are often a cause for resistors burning up. The bad motor will draw too much current and cause the heating that damages everything.

 

[CaptainXL]

Odds are that your resistor pack is OK!

Get the properly redesigned Delphi harness from Amazon here: GM Blower Motor Resistor Harness Connector 88953358 : Amazon.com : Automotive

It's much cheaper and has been working great for a year for me.

View attachment 23030

 

[neelskit]

Change the end on the harness, put in another new resistor, and change the blower motor as well. Blower motors that are starting to go bad are often a cause for resistors burning up. The bad motor will draw too much current and cause the heating that damages everything.

You can check the current draw of the blower motor with a 12V battery/power supply and a DMM to be sure.

 

[767Jockey]

given all the good responses I've gotten here, is to buy the connector plug that the Captain linked to, a new Delco resistor, and install them. The blower motor seems fine, it sounds and runs as it always has. I'll run the motor and feel the wires. If they get as hot as they were with the old stuff, I'll pull the motor and check it our really carefully. If they're relatively cool, then I'll button it up and hope for the best.

 

[JerryIrons]

I had a resistor overheat, blower motor seemed fine. 3 months later my blower motor died on me. This time I replaced all 3, motor resistor and connector. The crimps that I had used had softened up quite a bit, this time I soldered them together. I'm not saying your motor is bad, but keep it in mind. Not all DMM can measure amperage.

 

[Kurb]

You can check the current draw of the blower motor with a 12V battery/power supply and a DMM to be sure.

What is the acceptable range of current or resistance (preferred) for the blower motor? I have a bad resistor and melted connector. I only want to fix this once, but I also do not want to waste money on a blower when it is not really needed. Something had to cause the connector to melt, so I am guessing the motor is pulling too much current, which would also kill the resistor. From other posts, however, it seems like most people just replace the connector and resistor.

 

[Tiggerr]

Yep. A blower motor that is going out can smoke a resistor.

 

[MAY03LT]

I lost #5 (no melting, relay in resistor crapped out) and after replacing the resistor the motor clamped at 23A and some change. I replaced the motor just to be on the safe side and it was right around 22A. I think I would have been ok without doing the motor but peace of mind is a good thing to me.

 

[BlazingTrails]

I've recommended this several times before for many issues but I will mention it again, On any electrical connections that I work on I put dielectric grease in the connections, it keeps them from corroding and also on higher current connections such as the fan connector it will isolate the electricity and keep it from arching. Arching is what's melting the connector. when you put the connectors together it may be a good idea to take a scratch awl or pick and squeeze the spade connectors in the plug tighter.

It's like Frank's Red hot sauce, I put that sh*t on everything :Yes:

Example: