HVAC controller(s) (help needed)


EasyEric

GT Owner
Mar 6, 2006
355
Florida and Georgia USA
Pete,

I was planning on keeping it and attempting repair myself (I'm an electrical engineer) but I have no particular sentimental attachment to the part so I'll seriously consider your proposition.

I'll take photos of the part and post them here to give you a better idea of the damage.

Eric
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
Eric, if you're an EE, you try it first. I look forward to the before and after pics. Thanks in advance.
 

EasyEric

GT Owner
Mar 6, 2006
355
Florida and Georgia USA
Pete,

Please see the photos below. I've circled the area with the damaged component (RED on the old unit, GREEN on the new unit).

After inspection with a jeweler's loupe, it appears the part is a capacitor and not a resistor as the silkscreen showed 'C3' as the component designation. Also, as you can see, it is a surface mount component.

I may not devote the time to to attempting to repair it as my surface mount skills aren't as good as my through hole. let me know if you're still interested. i'm sure we can work something out.

Regards,
Eric

Old_Unit.jpg

New_Unit.jpg
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Any competent tech can replace the part.

1 of 3 engineers could. (I'm in the other 2)

However, once C3 is replaced (with what value?) how do you know it works? Are you going to take your car apart and try it again?

And I'd always wonder what took C3 out. Usually these componts don't fail on their own. So what "took it out"? That would be my concern.

Without schematics and a tester, it looks like a good scrap bin part to me.


Just my 2c (P.S. +45 years experience).
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
Pete,

Please see the photos below. I've circled the area with the damaged component (RED on the old unit, GREEN on the new unit).

After inspection with a jeweler's loupe, it appears the part is a capacitor and not a resistor as the silkscreen showed 'C3' as the component designation. Also, as you can see, it is a surface mount component.

I may not devote the time to to attempting to repair it as my surface mount skills aren't as good as my through hole. let me know if you're still interested. i'm sure we can work something out.

Regards,
Eric
How much will you let it go for?
 

texas mongrel

GT Owner
Mark II Lifetime
May 3, 2009
1,661
Houston Texas
I had a Vintage A/C unit in one of my other cars (they made the GT's system). The circuit board went bad. VA walked me through a series of checks before concluding it was definitely a bad board and then sent me a new replacement board free of charge. They told me that sometimes a speck of moisture can hit the board in exactly the wrong place and cause things to fail. Vintage Air is a class act (and not just because they're based in Texas!) and I'm glad they're providing the units for the new FGT
 

EasyEric

GT Owner
Mar 6, 2006
355
Florida and Georgia USA
Peter,

Sorry for the delay in responding. I just saw your post.

I'll PM you when I get back to the house tonight.

Regards,
Eric
 

EasyEric

GT Owner
Mar 6, 2006
355
Florida and Georgia USA
Pete,

Check your PM.

Eric
 

vyprgt2

GT Owner
Mark II Lifetime
Sep 9, 2005
609
CA
So, today the white lights under the hvac knobs on one of my GT's decided to stop working - right before they stopped working, they cycled back and forth between illuminated and off for brief times

The two small orange lights still illuminate.

All of the hvac functions seem to be fully operational- the white lights just won't illuminate

Any ideas before I try to pry off the center console? Also, can anyone post a couple of general instructions on the safest method of getting the console off?
 
Last edited:

vyprgt2

GT Owner
Mark II Lifetime
Sep 9, 2005
609
CA
I checked the ground by the battery, fuse 7 and fuse 32- not the culprits.

I got the panel off around the e brake. Does the panel around the Mac subwoofer come off next?
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Yes. The. The screws down each side. Use lots of blue tape to prevent scratching.
 

vyprgt2

GT Owner
Mark II Lifetime
Sep 9, 2005
609
CA
OK, so I took the a/c knobs and board module out of the GT and plugged it into my other GT- in the other GT, the module's white LEDs light up just fine. I put it back in the correct car, and they don't work. I guess the module is fine and the wiring was not loose.

Any ideas of what to try next? Fuse 7 and fuse 32 seem ok, as does battery ground.
Could it be the wiring at the headlight switch?