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Temp up, but not down



Hi, everybody, I'm brand spankin' new to posting on this forum and have just recently purchased my first vette (of many, I'm sure now) '92 blue coupe, and am figuring things out as I go... couple of things right now are bugged a little and I'm wondering if there are quick solutions to any of them that I might be missing, or little tricks, or whatever (might be something really simple too)

1. The temperature goes up just fine, and its at 90 now (hehe) but I can't seem to make it go back down, the gauge shows the outside temp, then when I press the up it flashes the 90, but if I press the down, nothing happens...

2. Both the rear window defogger and the main defogger buttons do not light up, or appear to activate the defoggers when I press them... pretty sure something here needs fixed, but again, any help would be greatly appreciated

3. the cd player on the cd-tape-am/fm combo takes in the cd's but instead of playing them just makes little beeping noises that can be heard when you turn the radio up enough.

anyways, aside from those three things, everything on it is great and I can't believe what I've been missing for this long (though it's probably not the best idea for me to have had a 'vette before I was 20... it's a lot of responsibility) also wanted to comment on how helpful and nice a community this is to have been reading over the past few weeks, and hope to be able to help somebody when I've got some experience too :p...

Ok the AC thing....

Try disconnecting the battery for a few minutes..that will clear the HVAC memory

This might clear the defogger thing

if it does the same thing.. we have to talk to the CCM to see what errors are lurking.

Does the dash flash SYS?

The CD I'll have to post a good shop that repairs them..nothing easy there.


thanks for that advice a lot, we disconnected the battery for 5 then reconnected it and started it up and it cleared up both the temperature problem as well as the defoggers (they both lit up and appeared to work) then later on in the day it went off again, so I'm going to reset it again to see maybe if it was something I did to mess it up, or if there's something more wrong with it... thanks again
There is a fault in the system....

I'll bet the green light on the HVAC is flashing

It means there is a stored code in the system somewhere.

I forgot in what order you press the buttons to get the code to appear.

To read the CCM
Key Off
Have pen & paper ready
Jump pins a & g in tha ALDL connector
turn key on
This will start the Auto diag of the CCM
The numbers where the speedo lives will give you codes
eg C 51 or H 51
( the C means current H means History)
and below there will be another number
( eg 1.1, 2.1 etc)
These will tell you the MODULE at fault.

To exit
Key off
remove the jumper

Write this info down

I'll get my book
and away we go.

Enter the AC DTC zone

Diagnostic Trouble codes

So the MODE button you have depresses will flash for one minute the go out...

Hold the arrow up & the arrow down buttons for 5 seconds the display will show 00
( to let you know your in )
Hit the Auto button
and is should scroll through the code(s) that you have

00= No problem
01= temp door motor goof
02= temp door motor goof ( different problem )
03= ambient sensor OPENED UP/disconnected
04= ambient sensor Shorted out/ kaboom
05= internal sensor OPENED UP/disconnected
06= internal sensor Shorted out/ kaboom
07= Solar sensor ( in dash ) open
09= Low gas
10= CPU has blow it's mind

After this is done...by pressing the up & down arrows you can pole the different circuts and when you find the one you are looking for
Press AUTO
and it will tell you what it thinks it sees.

To get out of Diag's

Hit defrost..( or any other AC control)

Ta Da

wow - thanks

jeez... gonna have to wait until tomorrow to do all of that stuff because the weather stinks right now, but thanks a billion, I'm sure that should cover just about everything to find out where the problem areas are - and gonna contact the radio website too... thanks again

Like I said

Best Vette website on the planet!

So Dillon

What's up with the AC thing?

working intermittently

been riding it around a lot to test it out and find out all the little bugs before my 30 days is up from the dealer where I purchased it... the temperature up and not down thing is becoming less and less a problem as I've only had it happen once or twice now in 15 or so times driving it... so we'll see what happens there... the light for the rear window defroster/defogger now comes on, but doesn't remove any frost or fog even when it is fogged up or light frost on the window, so something still needs some work there... other than that, it's good :)


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