[hcmdx]

Does anyone out there have experience with a Rear AC/Heater unit that stops working? I have checked all the fuses (Two main boxes in engine compartment and interior). It appears to be electrical since nothing goes on, on the rear panel. Tried putting the rear on manual mode, still nothing.

 

[frostyra]

There are four fuses involved: In the underhood fuse relay box, fuses 41 (120A), 42 (50A), and 52 (30A) can all keep the rear blower from running, as can fuse 3 (7.5A) in the driver's side underdash fuse/relay box. The rear blower motor relay could also be a culprit, as could the rear power transistor, or even simply a bad ground connection. You'd really need a Service Manual (www.helminc.com) and pretty good electrical knowledge to troubleshoot it yourself.

Good luck!

 

[Gregc]

Mine has always worked fine, as a matter of fact the kids always complain that it is too cold and the want the Manual control turned on so they can turn it off!! You can check to see if the A/C has set any codes, here is the procedure.

1. Turn the ignition switch ON (II).

2. Press the AUTO Button and then the OFF button. Continue to hold both buttons down for 1 minute.

If there is any abnormality in the system, the tempature indicator will light up the segment (A through N) corresponding to the error. The Tempature indicator will then alternate every second between the errror code and "88" (all segments lit) and the error code segment (A through N).

Note: The system will only display the error code when the AUTO and OFF buttons are pressed. If you release the buttons, the display will go blank. To return to the display, simply press the AUTO then the OFF buttons again. If there is no abnormality the segments will not light up.

The segments they are talking about are the 7 segment LCD's used to display the Tempature. There are 14 segments and they are arrange from A to N. A is the top left vertical segment of the left number, B is the top left vertical segment of the right number. C is the Top Horizontal segment of the left number and D is the Top Horizontal segment of the right number. E is the top right Vertical Segment of the left number and F is the top right Vertical Segment of the left number. I could go on but you get the idea. If you get a code I can look it up in the Service Manual or you can buy a service manual at www.helminc.com for $67 and shipping.

If just the rear blower is not working it is probably a blown fuse, bad ground, bad rear power transistor, Rear blower, or rear blower relay. The 2 fuses to check are No. 52 (30a) in the under-hood fuse/relay box, and the No. 3 (7.5a) fuse in the driver's under-dash fuse/relay box. Good luck.


Greg

 

[Gregc]

I just tried that Error test on my MDX and could not get it to display anything? Sorry to duplicate your info Frostya, I type slower than you!!


Greg

 

[hcmdx]

There are four fuses involved: In the underhood fuse relay box, fuses 41 (120A), 42 (50A), and 52 (30A) can all keep the rear blower from running, as can fuse 3 (7.5A) in the driver's side underdash fuse/relay box. The rear blower motor relay could also be a culprit, as could the rear power transistor, or even simply a bad ground connection. You'd really need a Service Manual (www.helminc.com) and pretty good electrical knowledge to troubleshoot it yourself.

Good luck!

I am not sure which fuses you are reffering to. The primary fuse box under the hood only goes to fuse 24 and the secondary box has 4. What are the names of the fuses that you are reffering to?

Thanks in advance

 

[hcmdx]

Mine has always worked fine, as a matter of fact the kids always complain that it is too cold and the want the Manual control turned on so they can turn it off!! You can check to see if the A/C has set any codes, here is the procedure.

1. Turn the ignition switch ON (II).

2. Press the AUTO Button and then the OFF button. Continue to hold both buttons down for 1 minute.

If there is any abnormality in the system, the tempature indicator will light up the segment (A through N) corresponding to the error. The Tempature indicator will then alternate every second between the errror code and "88" (all segments lit) and the error code segment (A through N).

Note: The system will only display the error code when the AUTO and OFF buttons are pressed. If you release the buttons, the display will go blank. To return to the display, simply press the AUTO then the OFF buttons again. If there is no abnormality the segments will not light up.

The segments they are talking about are the 7 segment LCD's used to display the Tempature. There are 14 segments and they are arrange from A to N. A is the top left vertical segment of the left number, B is the top left vertical segment of the right number. C is the Top Horizontal segment of the left number and D is the Top Horizontal segment of the right number. E is the top right Vertical Segment of the left number and F is the top right Vertical Segment of the left number. I could go on but you get the idea. If you get a code I can look it up in the Service Manual or you can buy a service manual at www.helminc.com for $67 and shipping.

If just the rear blower is not working it is probably a blown fuse, bad ground, bad rear power transistor, Rear blower, or rear blower relay. The 2 fuses to check are No. 52 (30a) in the under-hood fuse/relay box, and the No. 3 (7.5a) fuse in the driver's under-dash fuse/relay box. Good luck.


Greg

Tried the error test and got no errors. Thanks for the idea.

 

[frostyra]

hcmdx: I'll have to look tomorrow; it's bedtime here now!:24:

 

[Gregc]

The fuses I was were referring to, No. 52 is under the hood attached to the passenger Strut tower in a fuse/Relay box. The fuse is labled as 30a REAR A/C. The second fuse is under the dash on the Drivers side right next to the parking brake in slot 3 Labled as Heater control A/C Clutch relay. Of the 2 my bet would be the one under the hood, if the one in the passenger compartment was bad you would have no A/C at all. The same goes with the 120a fuse under the hood, if it were blown nothing on the Car would work as this is the main battery fuse. If it is not the fuse there are several tests to see if it is a bad ground, power transistor, relay or fan. Hope this helps!!


Greg

 

[frostyra]

Gregc: Thanks for the location info. Couldn't have said it better myself!:2:

 

[hcmdx]

The fuses I was were referring to, No. 52 is under the hood attached to the passenger Strut tower in a fuse/Relay box. The fuse is labled as 30a REAR A/C. The second fuse is under the dash on the Drivers side right next to the parking brake in slot 3 Labled as Heater control A/C Clutch relay. Of the 2 my bet would be the one under the hood, if the one in the passenger compartment was bad you would have no A/C at all. The same goes with the 120a fuse under the hood, if it were blown nothing on the Car would work as this is the main battery fuse. If it is not the fuse there are several tests to see if it is a bad ground, power transistor, relay or fan. Hope this helps!!


Greg

Checked all the fuses and ran the test, still nothing. It looks like a trip to the dealer this week. Thanks for all the advice. Will post answer to the problem when I talk to the dealer.

 

[megabuck2]

hcmdx,

I hope I am not sounding like an idiot, but you do know that the AUTO needs to be on for the Real AC to be working, right?

Just mentioning it since I just found out couple of days ago that you can't turn the rear ac on by itself...A/C system needs to be on AUTO (or at least turned on ) for the rear ac control to work.

good luck and please post what you and the service dept find out.

Mike

 

[hcmdx]

hcmdx,

I hope I am not sounding like an idiot, but you do know that the AUTO needs to be on for the Real AC to be working, right?

Just mentioning it since I just found out couple of days ago that you can't turn the rear ac on by itself...A/C system needs to be on AUTO (or at least turned on ) for the rear ac control to work.

good luck and please post what you and the service dept find out.

Mike

I am aware that the AUTO needs to be on, thanks anyway. I will post the repsonse from the service dept when I find out.

 

[kblake]

I am aware that the AUTO needs to be on, thanks anyway. I will post the repsonse from the service dept when I find out.

Did you ever resolve this problem? I am having the exact same problem with my 2003 MDX. all of the fuses are intact, but the rear blower won't come on at all, in any position.

Ken

 

[lester123]

Did you ever resolve this problem? I am having the exact same problem with my 2003 MDX. all of the fuses are intact, but the rear blower won't come on at all, in any position.

Ken

I had same problem. It was a bad transister assembly. Dealer wanted about $200 to repair. I have 75K miles. Since this is a prevalent problem, I asked them to call Acura and to request that job be done complementary. They did, and then there was no charge.

 

[Sinecure]

Sorry no one saw this post earlier. It would have saved you some trouble.

Here's a Previous Post you need to read.

All your questions answered there. Easy DIY fix if you have a soldering iron. Heck, I went and bought an iron and did it myself - first time I'd soldered anything in 20 years.

 

[rrcompton]

Sorry no one saw this post earlier. It would have saved you some trouble.

Here's a Previous Post you need to read.

All your questions answered there. Easy DIY fix if you have a soldering iron. Heck, I went and bought an iron and did it myself - first time I'd soldered anything in 20 years.

yup

I had the same problem, if your rear a/c lights up on the front a/c display...all you need to do is;

go to: www.digikey.com

look for part number P10920-ND
(thermal cutoff 114C 2A/250VAC)= .45cents each

takes less than 15mins to fix it

Mine works PERFECT now!!!

 

[Hawkeye83]

This link is not working:

"Here's a Previous Post you need to read."

Any idea what info was in that thread? Just ordered the part from digi-key as described above, and will check the fuses mentioned...

 

[MassX]

Try these links also, you'll find what you need.
http://www.mdxers.org/forums/14-problems/17346-broken-rear-ac-grrr.html?perpage=15&pagenumber=3

Rear blower Transistor Fix - Honda Pilot - Honda Pilot Forums

It's a very easy fix, good luck

 

[wenzelr]

Just needed a cleaning

I was having the same issues. Rear lights up but no air coming out. So I ordered a few thermal cutoffs from DigiKey as recommended for a couple bucks.

Removed side panel by drivers foot as described and pulled out the transistor assembly (large plyers helped as mine was pretty stuck). Everything looked fine and it was not hot.

Cleaned fan cover (which was amazingly dirty). Removed cover to clean and rotated fan a few times to make sure it was not blocked (seemed OK). Scraped fan cover clean and replaced.

Put everything back and it worked again. Something must have been blocking the fans movement. Now it blows ice cubes again and now the kids are yelling to turn it off (never happy).

 

[LJwolfeman]

Error code is bottom right segment....what is that???

Mine has always worked fine, as a matter of fact the kids always complain that it is too cold and the want the Manual control turned on so they can turn it off!! You can check to see if the A/C has set any codes, here is the procedure.

1. Turn the ignition switch ON (II).

2. Press the AUTO Button and then the OFF button. Continue to hold both buttons down for 1 minute.

If there is any abnormality in the system, the tempature indicator will light up the segment (A through N) corresponding to the error. The Tempature indicator will then alternate every second between the errror code and "88" (all segments lit) and the error code segment (A through N).

Note: The system will only display the error code when the AUTO and OFF buttons are pressed. If you release the buttons, the display will go blank. To return to the display, simply press the AUTO then the OFF buttons again. If there is no abnormality the segments will not light up.

The segments they are talking about are the 7 segment LCD's used to display the Tempature. There are 14 segments and they are arrange from A to N. A is the top left vertical segment of the left number, B is the top left vertical segment of the right number. C is the Top Horizontal segment of the left number and D is the Top Horizontal segment of the right number. E is the top right Vertical Segment of the left number and F is the top right Vertical Segment of the left number. I could go on but you get the idea. If you get a code I can look it up in the Service Manual or you can buy a service manual at www.helminc.com for $67 and shipping.

If just the rear blower is not working it is probably a blown fuse, bad ground, bad rear power transistor, Rear blower, or rear blower relay. The 2 fuses to check are No. 52 (30a) in the under-hood fuse/relay box, and the No. 3 (7.5a) fuse in the driver's under-dash fuse/relay box. Good luck.


Greg

Greg: I did the diagnostic test you described and the bottom right segment on the LCD shows up. What is that? Is that the transistor or something else?