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Hi,

Does anyone know how many amps the rear blower motor should pull with a direct ground (not through control panel). I replace one transistor and it blew the resistor. I shorted my blower motor and it runs and draws 8-9 amps on my clamp meter.

Jordan

2001 MDX
 

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rear blower defaults to on with no switching

I have a 2004 MDX and the rear air stopped blowing. I replaced the thermal cutoff. now my rear blower runs on maximum constantly and can't be controled. It even runs when I turn the air completley off. Has any one had this problem
Hello is there any follow up to this constant rear air on ?..I thougt that going with oem transistor part at Acura would avoid this , but here i am again.
Mine can turn off but only after engaging rear green air led button and ensuring rear air controls knob is in off position
 

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Jordan,

I can't look right now but there may be testing procedures for the blower motor in the factory service manual. You can buy a factory manual on ebay for super cheap and it comes in electronic PDF version (WONDERFUL TO HAVE!). I suggest buying one and following the suggestions in it for testing your blower motor and/or A/C control module. I do know that there is also a procedure similar to checking a CEL code on an OBDI car only it is for the A/C control module. If you have something going on with your A/C there is a series of key turns and pushed buttons that will run a diagnostic on the whole system. Your dash will then light up in sequence if it has any codes. You can probably search google for that procedure and it is in the factory service manual as well.

Electronic Version:

http://www.ebay.com/itm/2003-2006-Acura-MDX-service-repair-workshop-manual-PDF-almost-2500-pages-/251159459357?pt=Motors_Manuals_Literature&hash=item3a7a45361d&vxp=mtr

OR if you want a CD:

http://www.ebay.com/itm/Acura-MDX-01-02-03-04-05-06-Service-Repair-Manual-/251037067332?pt=Motors_Manuals_Literature&hash=item3a72f9a844&vxp=mtr

Salvatore,

It sounds like you may have a problem with your a/c control module if your rear heater doesn't turn off without the manual function on. This would be another problem that can be researched in the factory service manual as described above. I don't have any suggestions off the top of my head other than that...sorry!

Good luck to you both!
 

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Can anyone please provide information or pictures on how to replace the thermal fuse on the transistor? I've looked at the old post, but the pictures are missing. Thanks!
 

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Can anyone please provide information or pictures on how to replace the thermal fuse on the transistor? I've looked at the old post, but the pictures are missing. Thanks!
This is from my rusty memory from at least a few years back. (The front and rear units are very similar BTW) You access the component under the gearshift console. Remove carpet, unhook electrical connector, twist and pull out the unit.

There's a few screws holding a cover on one side or such; and then I think under that there is a metal heat sink/shield over the thermal fuse. Tou undo a screw or so on that and then you will see the thermal grease. The thermal fuse looks like a small wire with white insulation on it; it wraps around the bottom of the unit.

Your goal once you open it up to this point is to use a solder gun to just heat each end of this u-shaped wire at the solder joints enough to remove this fuse wire.

Dont overheat and burn off the solder or make it drip away because you can just use the same solder blob to attach the new fuse wire. Just bend the new fuse to shape and then heat up one solder ball and melt it to the new fuse end; do the same at the other end.

I just left the grease as is and once the new wire is in place you just reassemble in reverse!

I am handy but I am no electronics guy. Screwdriver and solder irom tip and new fuse is about all you need...


hope this helps!
 

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Thank you for the information. I actually will be working on the front transistor.

Do you know how to pull apart the panel? Do you just pull it apart or is it held in by screws that need to be removed? Also, should I be checking any fuse to see if they're burnt prior to replacing the thermal fuse? Are the fuse inside the cabin or in the engine compartment? Last question, is the thermal fuse the same for an 04' MDX?


from the links on page 21 of this thread, here's that link to the Pilot site with plenty of pics!

Rear blower Transistor Fix - Honda Pilot - Honda Pilot Forums
 

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reds2k1, I think there is a separate "how-to" for the front a/c repair. You can find it pretty easily through a google search. It should be the same on an 04.
 

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Well...

...I never thought I'd need it but here I am. My rear HVAC unit stopped working today. I'm almost 100% sure it's a broken thermal fuse. Just thought I'd pop in to subscribe for now. I'll have to buy a fuse and do some soldering sometime in the near future when I get a chance!
 

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Just an update that I decided to order a couple of thermal cutoffs from Digi-Key as well. They were 86¢ each but shipping is still $8 to Canada. Interesting to see that the shipping rate to Canada hasn't changed over the years since it's been $8 since the early pages of this thread!

Is it coincidence that I had to re-solder a few connections on my Daytime Running Light module recently too (you guys in the U.S. are going,"Huh?" at this point!)? I guess over time the solder points just crack but I find it funny that this will be 2 solder issues in a relatively short span of time.
 

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Any solder jt that gets warm and then cools is subject to fatigue cracking. Solder is not too good in fatigue loading.

good luck
 

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I don't think so much it's solder itself in that particular environment, but the fact it prob lead free solder.
 

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Do you suppose they used lead-free solder back in the early 2000s on these cars? I Googled typical solder joint failures and came across this short summary:

Solder Joint Failures

Solder joint failures occur for various reasons: 1) poor solder joint design; 2) poor solder joint processing; 3) solder material issues; 4) excessive stresses applied to the solder joints, etc.. In general, however, solder joint failures are simply classified in terms of the nature of the stresses that caused them, as well as the manner in which the solder joints fail.

Most solder joint failures fall under three major categories: 1) tensile fracture due to stress overloading, which is short-term; 2) creep failure due to the application of a long-term, permanent load; and 3) fatigue failure due to the application of cyclical stresses. Of course, more than one of these stresses can act on a solder joint in a given situation, so solder joint failure analysis can be challenging at times. Add to this the fact that solder joint degradation due to other factors such as corrosion can occur.
 

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UPDATE:

I ordered 2 thermal cutoffs on Thursday February 14th, 2013 from Digi-Key and received the items the next day! I only got around to working on the car Sunday February 17th, but everything went pretty well (thanks to the wealth of information on this site) and now my rear HVAC blower is back in full working order once again. :29:

I ended up insulating the thermal cutoff with polyolefin heat shrink tubing then applying an anti-oxidant compound similar to thermal grease at the interface between the transistor assembly and the heat sink. While I had the lower panel open, as others have recommended, I picked off the enormous dust build-up at the rear HVAC filter/screen. Didn't have to use a vacuum since the layer of dust was pretty solidly packed together. Ewww.
 
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