Blower motor stays on

[meridian6]

FFShawn. What did you finally do to solve your problem?? I have the identical situation and have already blown two of the new designed Power Modules and do not what to make it three. Blower motor is good and not drawing too many Amps. Did you end up replacing relay, blower motor, in dash ATS control head or some combination of the three to resolve the continuous high fan and repeated Blower Motor Power Module (Resistor) failures. Would appreciate hearing from anyone else that eventually solved this problem.

[Bill Grissom]

Originally Posted by meridian6

FFShawn. What did you finally do to solve your problem?? I have the identical situation and have already blown two of the new designed Power Modules and do not what to make it three. Blower motor is good and not drawing too many Amps. Did you end up replacing relay, blower motor, in dash ATS control head or some combination of the three to resolve the continuous high fan and repeated Blower Motor Power Module (Resistor) failures. Would appreciate hearing from anyone else that eventually solved this problem.

Even though not asked, I'll chime in. My blower is still working fine at least 3 years after installing the new-design module with round pins. I assume you changed your climate filter (~$22 at rockauto). If not, it could restrict air flow and over-heat the module. You could always run without a filter, since most cars don't have one. Maybe you have poor air flow from something else, like a non-functioning air diverter door. Perhaps you could remove the module and feel for air flow out the hole. For that test, use one of your shorted modules since a good one could over-heat if not in the airstream.

[meridian6]

Thanks. Filter out and lots of air flow. The two new modules blew within minutes of install. They worked fine after plugged up and screwed in. Moved blower speed up and down and worked fine for a few minutes, then the module failed and blower defaulted back to HIGH Speed. Thanks for the input. Still at a loss as to what is causing these to go so fast.
Keith

[Bill Grissom]

meridian6,

If in your shoes (might be in a few years), I would first search for other reports of new modules failing. It seems that in our global economy, parts with different branding often originate from the same factory, often in China or India, and many rebuilt auto parts have a shoddy record of testing and quality control. It could be a bad batch is out in the supply chain. I would buy the next module from the dealer to be slightly safer.

My next suspicion would be the blower motor itself. I wonder if this electronic control is closely designed to the motor, so that degradation of the motor might affect it. If the output to the motor is just 2 wires, it is probably a simple DC permanent magnet motor with brushes. In that case, sparking by worn brushes might be the culprit, and they can sometimes be replaced. If more than 2 wires, it might be a more complicated "brush-less" DC motor, in which case the speed controller interaction is more complicated. Sorry I don't know the details. Check on rockauto if the same motor is used in ATC and regular climate cars. If so, you are more likely to find a vehicle to rob in the junkyard. Otherwise, let us know what a new motor costs and also how easy it was to change.

[meridian6]

It is a two wire motor. I have ordered a lot of five transistors to replace the one that fails in the power module, so I will see if a got into a bad lot of blower motor control modules if one with a new replacement transister doesn't fail. This may take awhile, but will post my results. FFShawn did indicate that he had to replace his blower motor with no further problems. I just hate to replace a blower motor that "appears" and "sounds" fine - but it is ten years old! Thanks again.

[paulburkhart]

hey guys/gals! got a 1999 chrysler 300m i have replace the control panel and the blower control module with no luck i have read that if those two things dont fix it i should check for varible voltage at the red/lime green wire at module connector i have done so and found no varible voltage as i turn the fan speed switch, now all the forums and diy sites do not show any further test to confirm whats wrong the memos say "test ged/lime green wire at module if varible voltage replace module" but nowhere does it say if no voltage check this....... any help will be greatly appreciated. thanks paul

[meridian6]

Thanks for all the advice. Repaired Module doing the trick since I replaced Blower Motor. Old motor drawing 22AMPS running on HI, New motor drawing 18AMPS, but the startup draw on old one sometimes was in the 30's and 40's. The new one maxs out at about 25 AMPs.

[stvphillpss]

Hey all. I've had a similar problem as the one stated here. A few months back my blower motor went out and after replacing it my fan was stuck on full. I could change the temperature and where the air came out, but nothing else. Because of lack of funds I have been unable to replace the blower motor power module. I woke up this morning to no fan at all. I guess what my question is is can the blower motor control module get so bad that it will keep the motor from blowing at all or have I blown the motor again?

[woldog]

Hey everyone. I realize that this post is several years old, but it seemed to be the best discussion on this issue that I could find, so I thought I'd start here. I have a 1999 LHS with the symptoms everyone else is describing, so I went online to find the replacement part. From what I can tell, the part is over $150, and not the $25 or so previously mentioned. Does anyone know if the price for this part as dramatically increased for some reason or if I'm looking at the wrong part? Here is what I think I need - http://www.autozone.com/climate-cont...0053_0_0_5396/

Any help is appreciated.

[mjt11860]

@woldog, what did u find out?

[woldog]

No one ever responded to my question, and I didn't pursue the issue further. I still have the issue, although it's more intermittent than I think others experienced. It really is like my climate control has a mind of its own. The worst is on a 5 degree Illinois morning when I get nothing but ice cold air blowing at high speed out the defrost. Thankfully I have a short drive to work. It looks like the price of that part has dropped a little, but without some confirmation that it's the correct part, I'm not going to waste my time or money on a purchase. Maybe someone out there will take a look and let us know.

[jstmachine]

woldog, yes that is the correct part you need. I just replaced one in a 300M, pain in the rear as there is no room for wrenches down there. I ended up going to the web and found it for $116 plus delivery. Blower seems to work fine, but was just told there was some smoke coming through vents, so I am hoping its just something that got on it that is burning off. The one I purchased came with a 5 yr warranty but really dont want to go through the hassle of changing it out since its such a pain to do.

[Veefre]

I just got through fixing this very same problem on my 300m.

I seem to recall a reduced air flow from the heater prior to the problem. Then I noticed the blower was on full blast whenever the car was running, no way to turn it off.

I got a new motor control (resistor) but couldn't get the old one out. So I just hung the new one off the wires and run the car for a bit. After about 10 minutes the heater/AC shut off completely. I noticed the new motor control module (hanging under the dash) was HOT to the touch. So I stopped using the heater for a while. I got a new blower motor and installed that (not easy) and put the motor control module in its proper place. Now the system works much better, can be turned off and on, and fan speed changed. The old blower seems to have significantly more resistance to turning, so I'm assuming the bearings in it went bad. The only new problem is that it seems it always calls for the AC to be on ("*") when the system is on "Auto". Usually that only happens for the first few minutes of operation, but this seems to be permanent. My work around for now I just to run the system in manual mode if I just want heat or air and no AC. I have a new motor control unit on order and will see if that fixes this final issue.

Bottom line, and I've seen others mention this as well, if the blower motor bearings get sluggish, then the blower motor control unit overheats, and eventually fails. Usually it seems it fails to a mode where the blower is always on. I suggest that if the air output seems diminished for some reason, to replace the blower motor before the blower motor control unit gets fried.