How-to Use HVAC Display as Tachometer - Page 2 - ZR-1 Net Registry Forums

efnfast · 07-01-2012

My 90 #1786 is in C.

ghlkal · 07-01-2012

Quote:

Originally Posted by scottfab

What is the Serial number of your 90?

#2180

The display wasn't showing a temp in F, it appeared to be about 1/2 the temp gauge reading. So it could be in C ...

aafc · 07-02-2012

my 1990 #2546 temp shows c

John
1990 white/black auto eq.

scottfab · 07-02-2012

I checked mine on #16.
It is indeed in C.

I was reading my notes wrong in the manual.
I placed an arrow into the table which is missing #16 and wrote
"16 is the water temp not in F". So much for my hand writing.
I missed the "not" when reading it.

Sorry for the confusion.

scottfab · 07-04-2012

Quote:

Originally Posted by Dynomite

I am now wondering what other interesting diagnostics are available similar to the HVAC diagnostics?

There is a lot of diag stuff (on a 90 MY) via the ECM and displayed on the dash, both active and passive. As I remember this is not available on other MYs. I should say there is some there but not as much as on the 90.

VetteMed · 07-04-2012

Quote:

Originally Posted by Dynomite

2. Since the parameter #16 digital readout is in deg C where deg F=((9/5)(deg C) +32) and the gauge is analogue can we assume the temperature data for the HVAC digital temperature reading is from the same sensor and exact (in other words like the tachometer we can calibrate the temperature gauge)?

The temp display is taken directly from the ECM, which gets its information not from the gauge sensor, but from the other sensor right next to it.

VetteMed · 07-05-2012

Cliff, that's correct!

Livin' in the 80's · 04-20-2017

Quote:

Originally Posted by VetteMed

The temp display is taken directly from the ECM, which gets its information not from the gauge sensor, but from the other sensor right next to it.

Do you know the locations of these two sensors are located?

Paul Workman · 04-20-2017

Quote:

Originally Posted by Livin' in the 80's

Do you know the locations of these two sensors are located?

Yes. They're both located on the drivers side IH, toward the front. The plenum has to be removed to access them.

Gunny · 04-20-2017

doesn't seem to work on mine

07-01-2012	#11
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,574	Re: Use HVAC display as tach My 90 #1786 is in C.

07-02-2012	#13
aafc Join Date: Feb 2010 Location: Summerfield, FL Posts: 434	Re: Use HVAC display as tach my 1990 #2546 temp shows c John 1990 white/black auto eq.

07-02-2012	#14
scottfab Join Date: Jan 2009 Location: Portland Oregon metro area (Washington side) Posts: 3,193	Re: Use HVAC display as tach I checked mine on #16. It is indeed in C. I was reading my notes wrong in the manual. I placed an arrow into the table which is missing #16 and wrote "16 is the water temp not in F". So much for my hand writing. I missed the "not" when reading it. Sorry for the confusion. __________________ Scott Vett owner since 1979._It's about the car and the people Last edited by scottfab; 07-04-2012 at 12:38 AM.

04-20-2017	#20
Gunny Join Date: May 2005 Location: Georgia Mountains Posts: 918	Re: Use HVAC display as tach doesn't seem to work on mine __________________ George Jones Founding Member #14 www.zrwon.com

07-05-2012	#17
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,816	Re: Use HVAC display as tach Cliff, that's correct!