You mention it's not the resistor but you don't mention if you changed it out or not. Sounds like the motor is good because it runs when you jumped the ground wire. The ground for it is on the passenger side fender behind the air box.

 

I have the same problem but I swapped the resistor with a new one and still isn't working

 

hello. i had the same problem. remove you glove box and you will see a connector. unplug it and ill bet the brown wire/connector is burnt. i just jumped the brown wire with a but end splice.

 

Open your passenger side door. Remove the plastic trim right on the floor. Under where the door would be when it's closed. Then remove that kick panel under the dash. There should be a big blue plug behind there. Unplug it and check the connections. I think it's the brown wire. It melted in that plug and caused it to lose connection. I bypassed the plug and it solved my problem.

 

This

 

Maybe the blower motor is toast

 

:welcome:

Power goes from the fuse directly to the blower. All control of the blower operation is done using the ground side of the circuit. You should always have 12 volts at the brown wire of the blower connector. You won't get 12 volts by metering the brown and orange leads, if the ground is defective.

There aren't any HVAC grounds in the ground point on the left side. The compressor ground is G103, on the engine block.

If you don't have any blower operation at all, it is most likely something other than the resistor module. The high speed circuit bypasses the resistor module.

As mentioned above, there are other connectors, in the circuit, that have been problematic. One mounted on the HVAC case, behind the glove box, and one behind the right kick panel. They are both inline connectors.

To get access to the HVAC Control Module you will have to remove the trim panel around it. It is just retained by some spring clips, so you can just pry it off with a flat tool.

Probably a good idea to resolve the issue regarding the blower, then come back and see if we can help with the cooling problem.

 

This sounds familiar. Guess I'm going to tear into mine here shortly. Turned the truck on last night, fan ran for about 4 seconds then just stopped completely. No fan on any speeds. I didn't have a chance to mess with it due to the rain last night, so here's hoping I can do something with it.

 

Check the ground pack located next to your air filter along the passenger fender. This goes directly to the blower. Here is some images of it:

The blower motor ground ties into this ground splice. There is a member on CFans who works in the maintenance department for a company with a fleet of 355s.
After replacing numerous resistors and harnesses, he traced the schematics and found this ground. He ended up cleaning this ground on all the trucks and the blower motor issues ceased.

I removed the bolt holding the strap to the fender and lightly sanded the strap itself until I could see the brass. I then reinstalled with a stainless steel bolt and a star washer between the bolt head and the strap. Finally, I sealed it with a coat of touch up paint.

These pics show the location of the ground on the inside of the passenger fender behind the air cleaner. The first pic shows the air cleaner in place. In the last two pics, the air cleaner is removed for clarity.

 

Alright, I am having the same issues covered in this thread. I have checked all of the connections covered here and sanded/cleaned up the ground behind the air box. The blower will come on but will typically shut off after a few seconds. I can sometimes get it to run for a while on lower speeds but if I try to turn it up it will cut off. As I said, all of the connectors look great and show no signs of being burnt. I am at a loss on this one. Any help would be greatly appreciated.

 

The connector is weak.
It was barely durable enough to make it off the factory floor into our hands.

-it's made of a soft nylon-based super-cheapo plastic.
-the connector is also not robust.. it's whimpy.
The pins in the connector don't make really tight metal-to-metal contact when the two halves go together. The soft whimpy plastic doesn't help them maintain what little alignment they have by design. That causes them to heat up with the current drawn by the fan.


Open the connector (separate the two halves, the male and the female connector ends).
Look carefully to see if they look loose to you,.. like take the butt of a small drill bit and see if the ends of the pins are all loosy-goosy.... Think when you were a kid and your teeth were ready to fall out.

With the two connector ends together, use a good LED flashlight and look as you gently bend against the connector halves. You can see how chitzy it is.

Now.... add the heat of the resistor(s), which didn't have to be there at the connector body... They coulda been mounted separate and apart from the connector.. Same as they did for years, on the firewall nearby or even better, into the wall of the AC/heater box so the incoming air would cool it.

That connector would eventually be a problem even without the resistor heat added in.
They all fail eventually.

Most members here have purchased the GM update kit for the blower pigtail.
I repaired my '05 with a soldering iron and 18 inches of 16-gauge wire.
(only to say here that I don't know anything about the factory fix. I've never seen it)

Haven't actually yet repaired my (current) '08. Winter's coming... it's on the list.

I went to the dealer when shopping for my low-miles '08 single-cab expecting the blower fault and looking for it, Got $1k discount off the purchase price for that. He didn't know what I knew.

.

 

Do you have an more info on the GM update kit?

 

I don't know anything about the GM repair kit. I've never seen one.


From this thread though:
https://www.355nation.net/forum/how...lighting-electrical/6401-how-hvac-fan-motor-resistor-connector-replacement.html

I got these part-numbers:
Note:
The resistor needs to be purchased to complete the repair. You can either decide to splice in a replacement connector or replace the entire wiring harness.
Another option is to buy the resistor, connector and harness as a package. See photos below.

Resistor- p/n 15218254 $9.57*
Connector- p/n 15306069 $30.70*
Complete wiring harness - p/n 89019124 $23.52* (no splicing required)

Package deal (p/n PK15218254) $31.97

Maybe someone with experience using those parts can help here.

 

btw, didn't want to give the impression that you should expect that the connector alone is 'bad'.


A resistor being used that way to reduce the speed of a small motor is gonna get warm/hot.
It's normal and expected. The problem isn't the resistors themselves. They're doing what they are supposed to do.
(those resistors are also pretty whimpy though...I would have wanted them to be twice the size/wattage )

The problem is the connector. The resistor being mounted to the connector just aggravates the problems caused by the whimpy connector. What I was trying to get across is that the connector could easily become unreliable over time even without the resistors being there.
(like if the resistors had been mounted on the firewall or kickpanel)
The (normal, expected) heat from the resistors just makes it worse and kinda tips it over the edge.

 

Elect schematic located at: (from start page)
First Generation- Aesthetics- Electrical/Lighting/Security- 1st post: Electric schematics:
04-06 Canyon/Colorado= AC Heater.PDF
Note: I think the other years are wired very similar.

 

Elect schematic located at: (from start page) First Generation- Aesthetics- Electrical/Lighting/Security- 1st post: Electric schematics: 04-06 Canyon/Colorado= AC Heater.PDF Note: I think the other years are wired very similar.

Hi. Do you still have these schematics? Links aren't clickable anymore. Maybe u could email selina22perez at Gmail. Thank you in advance if you can .

 

Well, I ordered the replacement harness and resistor and got them changed out this afternoon. Still the same problem. It will not run on high (4) and will only run for a second on 3 before it shuts off and I have to completely turn the ac off. It will run on 1 for a while. I am suspecting heat to be the root cause but finding where it is causing the issue is my problem. Tomorrow morning I am going to try to splice the brown wire around the blue connector behind the kick panel. Any other places you can think of to check? I have pulled all of the connectors off and checked the for a little “wiggle” on the pins but couldn’t find anything that really stood out.

 

I am just curious, I have tried searching on here for it, but does someone happen to have a circuit diagram for this? The blue plug looks fine but I’ve found once the ac cuts off I can wiggle that plug and it will come back on. None of the pins look out of the ordinary, but I have narrowed the problem down! I am just wondering which wires are which now.

 

BigA24, see post #15 (3 up from here)

 

I've been a little delayed on getting my response on here but, I soldered a jumper wire (Brown Wire) around the blue connector under the kick panel and pulled the ground block behind the airfilter box completely apart. Even though it didn't look burnt or corroded i went ahead and buffed the pins with scotchbrite and gooped a pile of dye electric grease inside it and put it back together. So far the blower fan has been working perfectly! even on one day last week were the temperature got into the low 90's. thanks for the helkp and guidance! I will keep you posted if anything changes!:salute:

 

Great info on this thread, thanks to all and apologies for highjacking this old thread but it is closest to my problem. For background this is my daughters 04 colorado 2wd z71 with an I5 and 181K.

To start, no blower at any speed. I have plus 12 at fan but not ground. Fan works when it has ground. It will run sometimes on it's own for 10 to 30 seconds intermittantly. When it does work, I have ground on the brown wire behind the glovebox and lower kick panel. When it does not I do not.

I have cleaned the bolt, removed paint, and checked/sanded both the bus/common side and molex side of the ground sp106 behind the air filter.

I replaced the resistor and 4 wire connector.

My main confusion is stuck on why would I be seeing ground on the brown wire when it works? My interpretation of the wiring diagram says it has nothing to do with the fan motor and more to do with the PCM telling the relay to turn on. Many have said the brown wire was key for ground but how? I only see a black wire on the ground buss and the wiring diagram which turns into a resistor reduced or bypassed ground straight to the fan motor.

What am I missing?

Thanks for your time.

 

In the blower motor circuit, the power to the blower motor connector is a Brown wire. There should be 12 volts on that wire whenever the key is "on". The ground for the blower motor is an Orange wire that goes to the resistor module for fan speeds 1-2-3. The Orange wire also goes to the fans switch for "high" speed, which bypasses the resistor module. From the fan switch to the ground splice pack, the ground wire is Black.



There are two Black wires in the connector behind the kick panel. Both are ground wires and both go to the splice pack. One of the Black wires comes from the fan switch and one comes from the circuit board in the HVAC Control Panel.

Have you checked the condition of the terminals in the 10 pin connector that is attached to the face of the HVAC case? It is located directly behind the glove box. All lot of the HVAC wires go through that connector.

 

The brown wire to the blower motor is getting 12 V, and the black wire and the fan speed switch has continuity to ground and the black wires in both the connectors you mentioned. The orange wire and the fan speed switch to the connector pin looks a little melted. Would you suggest changing the fan speed switch out?

 

Thanks for the response,,, my daughter is at the YMCA taking her life guard test (odd for a sunday I thought) so I'll have to wait till tomorrow afternoon to take it further. I could have sworn my PowerProbe 3 was indicating ground on the brown behind the glove box when it was working. Would not be the first time I was wrong though.
I ordered the complete harness but did not see anything bad other than the resistor pack and connector which was already replaced. New harness should be here wednesday. It's the ground that is bothering me.I only see it when it works. 12+ is at the motor anytime it is in the on position and the key is on.
I had no discoloration on the connector behind the glove box or the one behind the kick panel. Both were disconnected and inspected twice.

Thanks again

Jim

 

I took the ground pack out and replaced it with eyelets to ground the wires. I tried cleaning mine but I believe it was internally broken, I have not had an issue since that repair

 

I received the main harness for it yesterday, if that doesnt take care of it i think ill go for the eyelets.

Thanks

 

Replaced the GM 89019303 harness it did nothing other than make the resistor connection pretty again as I had already replaced the resistor and harness pigtail last year and they were all one color.

Took the F and G connectors out of the ground block and put labels and eyelets on them and everything continued to run perfect one day later. Normally only ran for a minute or so. There was pull back on the F termination wire insulation so I guess it was getting some excessive draw and messed things up internally. I did the G as well because it is still part of the HVAC circuit. That is one cheaply made grounding bus, bad on GM for that one.

Moral of the story,,, if your AC indication comes on and you have Positive 12 at your fan but no ground at any speed on the orange wire at the fan then the problem is the F connection on the grounding block behind the air filter. You can try to clean it but if that does not work cut it out and put a heat shrink eyelet on it and all will be well.

Thanks for everyone's help.

 

The fan receives a constant 12V. The switch controls which ground the fan gets. One of the black wires in the ground pack by the air filter is the ground. It's a black wire, but I think they might all be black. On the link, if you click on picture #2 it will show how it all works. I had to copy and paste the image to a word document and blow it up so I could read it.
Good luck
https://www.2carpros.com/questions/chevrolet-colorado-2005-chevy-colorado-blower-not-working

 

I just had this issue this morning. Started the truck before work and fan was blowing, but 10 minutes later when I went to leave it would not run on any setting. Inspecting the blower motor connector I saw that I was getting 12V at the connector so it should be spinning. I ended up giving the motor housing a good thump and it started up. I'm thinking the bearings are on their way out so a new motor is probably necessary but at least I have heat again.

TLDR: if your blower is dead, crawl under the glovebox and give it a whack to see if that will cure it.