I swear I saw this post a while ago but couldn't find it. Anyway guess what? My AC only blows on the highest setting. Simple as a fuse, or do I have to send something to Shawn?
AC only blows on highest setting
- Thread starter Teej
- Start date
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- 4 September 2008
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- 906
send it to briank
Sounds great but I still don't really know what the issue is, I only know who can fix it
- Joined
- 9 May 2005
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- 523
The caps on the climate control board enentually leak, eating away at the board and the small traces in/on the board causing a loss of connectivity on the board, anyway thats my limited understanging of the issue of it only blowing on high speed.
It is probably just the beginning of issues, eventually you wont get anything on the climate control to work at all as more caps leak...
There are many, many threads on this subject...
It is probably just the beginning of issues, eventually you wont get anything on the climate control to work at all as more caps leak...
There are many, many threads on this subject...
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Based on your symptom it may not be the climate control unit. Mine was doing the same thing and I sent the CCU to Brian for rebuilding. He said it looked like it had been done before but he went through it anyway. Didn't fix the problem. There's also a resistor unit installed on the side of the fan housing and that can go bad too, and when it does this is the result, high speed only. Brian had me remove mine and send it to him for testing (@ no charge) - turned out to be bad and he doesn't rebuild them. There are some threads on replacing a transistor but Brian said it's not normally successful. A new part fixed the problem. I can post more but my NSX records are on another computer.
OK - Transistor Assembly, P/N 79340-SL0 A01, paid $226. Also replaced the fan motor, P/N 79310-SL0-A02, $190, because Brian said when the transistors go bad the motor isn't far behind, and a new transistor will fry if you don't replace the motor too. There was a TSB on this for some early cars - fan motor drags and overloads the transistor. I can probably find more info if you need it but there's info in the Prime wiki or faqs or somewhere.
OK - Transistor Assembly, P/N 79340-SL0 A01, paid $226. Also replaced the fan motor, P/N 79310-SL0-A02, $190, because Brian said when the transistors go bad the motor isn't far behind, and a new transistor will fry if you don't replace the motor too. There was a TSB on this for some early cars - fan motor drags and overloads the transistor. I can probably find more info if you need it but there's info in the Prime wiki or faqs or somewhere.
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Thanks Wavey1, your description matches my exact symptom, so perhaps I should look at that first. The AC works well, only on high, otherwise it feels like its barely seeping through. Sheesh.... just over $400... glad its almost the fall here in MI. Good information and now that i know another possible (and more costly) cause of the condition, I can fully research it. I just ordered a 1000+ page NSX pdf service manual CD and cant wait for that to get here.
Climate control failures are much more common then failure of the power transistor so blindly changing it is a waste of time and money. The service manual had a procedure for checking the signal to the power transistor to see if its there. If the signal is present then the power transistor is bad and as noted if it has failed the blower motor is bad too. If the signal is not there then the climate control needs repair or replacement.
and thats where you come in right? =) I loved this forum for 12 years before owning an NSX, I love this forum 1 day after driving it home. Thanks guys.
For Teej the cost of having the CCU rebuilt is way less then replacing the power transistor and its about 20 times more likely the problem is in the CCU.
I am running a CCU repair deal for NSX Prime member that have donated to prime.
I am running a CCU repair deal for NSX Prime member that have donated to prime.
+1 :thumbup:
There is a blower relay and a blower high relay. I am not sure what you mean by later then usual.
I have a simple fix for this problem but I need to be able to buy the connectors for the power transistor. It's a 3 pin plug/socket that mounts behind the fuse box under the hood. I've got photos but there are no markings other than A-1 (arrow character?) 3, on the socket. I don't want to dammage the dash by removing the CC unit. I've read the procedure and it's pretty involved. I'm an EE and my solution is an in-line wire harness with a wireless receiver that will drive the power transistor from a key fob. It also can be done with a simple snip of a wire but most folks don't dig that. I put a connector in the middle of the power transistor harness and inserted my circuit there, but removing the power transistor to install the connector is more than most people would want to do also, so the plug-and-play solution would be best. Anyone know where to get the conns?
OK will that give you speed control or just on and off? You have that with the blower high relay just turn the fan speed control to max and you have full speed fan. Taking out the climate control is not that involved, but I have done a few and its about a 10 min job to get it out for repair. Here is step by step picture instructions, http://nsxe-repair.com/CCUremoval.html the worst part is getting the clips in the bottom of the vent to release.
Once you have one failure like the fan only runs on high other problems are not far behind so getting the unit rebuilt at that point is way better then putting a band-aid on the most obvious problem.
BrianK,
I'm using a 5 button keyfob, 4 speeds plus off, and max with the fan switch in max. I read the removal procedure and the dealer even told me that taking out the AC vent without dammaging the dash is tricky. The manual shows how to pry out the AC vent using small flatblade screwdrivers and towels to protect the dash. You say it's not bad though? Fixing the unit is easy once it's out. I'm just overly cautious with my 1996, 23k miles. Here's my schematic just the same. The pic does have to be programmed but anybody could build it. Anyone who wants more info can contact me.
Thanks!
I'm using a 5 button keyfob, 4 speeds plus off, and max with the fan switch in max. I read the removal procedure and the dealer even told me that taking out the AC vent without dammaging the dash is tricky. The manual shows how to pry out the AC vent using small flatblade screwdrivers and towels to protect the dash. You say it's not bad though? Fixing the unit is easy once it's out. I'm just overly cautious with my 1996, 23k miles. Here's my schematic just the same. The pic does have to be programmed but anybody could build it. Anyone who wants more info can contact me.
Thanks!
