It is currently Mon Nov 20, 2017 7:40 pm


HVAC

"I'm trying to ____" and I can't ____"
Please use descriptive titles so people know what you're whining about. Knowitallism strongly discouraged

Moderators: Greg, Hatchtopia, needthatcar, Graverobber

  • Author
  • Message
Offline

Dan

  • Posts: 22
  • Joined: Tue Dec 11, 2012 9:54 am

HVAC

PostFri Apr 19, 2013 6:28 pm

Hello all,

About a month ago I got a really good deal on a 2005 Corvette because the guy was moving and couldn't take it with him, and because it had a few small problems. I bought it with the intentions of repairing the problems, driving it a little bit during the summer time, then flipping it for a small profit. So far I've fixed the rear view mirror (had a terrible wobble due to a bad design by GM), the power steering (water had found its way into the system and so I flushed it out and replaced it...so far all is well), and the heads up display (the mirror in the HUD unit had fallen off its hinges because the really cheap, thin plastic holding it up had cracked). Now all I really have left to fix is the HVAC.

I already have the dash pulled apart from when I fixed the HUD, and now I'm trying to figure out what to do to track down the HVAC problem. The system will turn on, and change the temperature of the air, but the motor isn't blowing anything. I figure there are three ways I can either progress. From least to most expensive: Track down the problem with a multimeter and replace the part, try to replace parts until I figure out which one it was, or take it to a dealership and tell them to fix it.

Ideally I'd like to use the multimeter to figure it out, but there are lots of intricate connectors wiring everything together and I have no idea which wire is which, and finding information online is a bit frustrating. Replacing parts holds a similar dilemma in that I have no idea where to start. Taking it to the dealership would be the easiest, but I'd hate to spend so much money, especially if it's a simple fix, and I'll take any chance I can get to practice working on cars.

So does anyone have any idea what the problem could be, or what you would do in my situation. Suggestions, tips, comments, help? Any and all would be greatly appreciated.

Thanks,

Dan
Offline
User avatar

skitter

  • Posts: 71
  • Joined: Fri Feb 24, 2012 9:20 am
  • Location: out, standing in my field

Re: HVAC

PostSat Apr 20, 2013 6:46 am

Dan,

I don't think I can give you a solid answer, and I think this will wind up costing you a few hundred dollars, but I can try to flesh out each scenario.

1. Solve it with a multimeter.
Personally, I would only attempt this with a Corvette Factory Service Manual, and those are $200. That plus the frustration cost of electrical problems would put it pretty much on par with

2. Replace the parts from cheapest to most expensive.
You may be able to do some tests beforehand (is the motor just two wires? or the adjustment knob?). But, when searching for something, it's always in the last place that you look. Obviously, because otherwise you'd stop looking. The dealer, in the interest of their own time, might go through the same replacement process to figure it out, so you might have a cost advantage there.

3. Take it to the dealer.
If the car is still drivable/legal with the dash disassembled, you might save some time and labor costs by taking it in as is. Which, if they immediately know the answer and don't have to replace multiple components, might put the cost on par with options (1) or (2).

Your mileage, as always, may vary.
Best of luck.
Offline

FrankTheCat

  • Posts: 91
  • Joined: Sun Jul 01, 2012 9:04 pm
  • Location: Foothills of the Adirondacks

Re: HVAC

PostSat Apr 20, 2013 1:02 pm

check the resistor pack for the blower motor. GM always used super low quality, underengineered wiring there.
Offline
User avatar

jeep_jeff

  • Posts: 163
  • Joined: Fri Feb 24, 2012 12:07 pm
  • Location: Oakland, CA

Re: HVAC

PostSat Apr 20, 2013 6:28 pm

FrankTheCat wrote:check the resistor pack for the blower motor. GM always used super low quality, underengineered wiring there.


I'm going to second that. Chrysler does the same thing, fan-no-go often means dead blower motor resistor. You may see if you can find a write-up in a Corvette forum. If you wanted to pull yours and see if it's the problem, you'd have to look up the pinouts, but resistors tend to fail open. Too much resistance would be the problem (this prevents much current from getting through, and then the motor doesn't get enough power to run). The ones for my Jeep are about $20, so it might be a place to start for tactic #2.
Offline

Dan

  • Posts: 22
  • Joined: Tue Dec 11, 2012 9:54 am

Re: HVAC

PostSun Apr 21, 2013 9:57 am

Thank you all very much! I think I'll try the resistor first and go from there. Might have to wait until next paycheck though.
Offline
User avatar

Stu_Rock

  • Posts: 77
  • Joined: Mon Feb 27, 2012 5:34 pm
  • Location: near Redwood City, Calif.

Re: HVAC

PostTue Apr 23, 2013 12:04 pm

FrankTheCat wrote:check the resistor pack for the blower motor. GM always used super low quality, underengineered wiring there.


I doubt this car has a resistor pack; it probably has a fancy solid state unit for controlling the blower motor. Also, in my 2005 Buick, GM used some seriously beefy 14 gauge wire for the blower. I'd bet that GM actually did the wiring very well in C6s. Now that I think about it, I'd actually say that GM cars of the last 20 years are the most competently wired in the industry. So I completely disagree with the statement above.

In my Buick, the blower motor itself stopped working last September, while I happened to be in Palm Springs. Literally NOT COOL. I managed to get it temporarily working by jiggling the motor each time I started the car, since it's easily accessible in my car.

When I got the replacement unit, I disassembled the original. It had basically worn all the way through the brushes. The car was 8.5 years old and had 62,000 mi at the time. The original motor was a very low-quality Korean unit (unfortunately, I got an OE replacement, but fortunately, it's a 10 minute replacement job in a Park Avenue).
Offline

danleym

  • Posts: 13
  • Joined: Fri Feb 24, 2012 9:07 am

Re: HVAC

PostThu Apr 25, 2013 11:58 am

From my experience with older cars, it's either the resistor or the blower motor itself. Also on older cars, neither of these is expensive and both are easily accessable, so you're not out all that much if you guess wrong the first time. I don't know what you're looking at for costs and amount of time to get to the parts with a 2005 Corvette. So guessing might be more of an issue. And being newer, there may be a little more electronics that could have failed.

Find a Corvette forum for the multimeter testing. I know most of those guys don't know a differential from a distributor, but I'm sure there are some very knowledgeable guys on them, too, who would be more than happy to look up a few numbers or even the whole diagnosis process for you in their service manuals. You could also peek in a Haynes Manual at an autoparts store and see if it has what you need. If it does, it's only $25, sure it may cut slightly into whatever profit you turn, but a lot less than taking it to a dealer.

Heck, I'd hunt on some Corvette forums and see if there are multiple people with the same problem. Usually if it's some oddball problem they happen to more than one person, so that could narrow down your diagnosis, too.
Offline

Dan

  • Posts: 22
  • Joined: Tue Dec 11, 2012 9:54 am

Re: HVAC

PostSat Apr 27, 2013 4:07 pm

Well I pulled the blower motor out. Attached to the bottom is some circuitry with three capacitors, one of which is a ceramic disk type. Underneath of it there's some burning with residue, and then on the bottom of the cover is a bunch of white powder, like battery acid. I think this may be the culprit. I think I'll be looking for a used one on eBay now. Thank you everyone for your help! I'll let you all know if that was the problem or not.

Return to Help!

Who is online

Users browsing this forum: No registered users and 1 guest

cron