Gold Lifetime Member
Join Date: May 2012
Location: Trumbull CT USA
Re: console temp gauge - where should needle be?
I went thru some Cooling Issues with my 69 427 BB, lots of info out there and tried a bunch of stuff.
And I agree with you as to What do the Different Lines on the Console Gauge or Dash Gauge represent for Temperatures.
I read somewhereabout the Yellow part of the Gauge being 212 Deg. and the Red being 230 Deg.
I had all my Gauges Cleaned and Recalibrated by Instrument Specialties in North Kingston, RI.
I can only assume my Gauge’s will give me the Proper readings, that being from where they get the Voltage or How much Resistance in the Circuit.
I started with a Hot Running BB and did get some “Pegging” of my Temperature Gauge.
I played with Thermostats 160/ 180 Deg., Fan Clutch, Radiatorsand I will say I finally got my Cooling issues under Control.
Using my eBay Laser Temp Gun, I felt the Readings on my Gauge was not correct, Always in or above the start of the Yellow Bar.
I also bought 3 Temperature Sending Units and all they do is Limit the Voltage going to Ground, I tried getting a consistent reading with each, bought a Mechanical Gauge just to see where my Temps were. Each Temperature Sending unit, all for the BB had different OHM resistant, from 570 to 640 OHM’s.
I had bought a small Hot Plate a while ago and decided to do a little test, Heated a pot of water till Boiling, Where I live in CT 210 Deg.+ . Had the Hot Plate on top of the Radiator Support, Put the Mechanical Gauge sending unit and one of the Sending units with a Jumper only to the Threads,
Mechanical 210, Console Gauge – pegged.
Kept the water at a Boil, switched the 3 Sending units around and one of them stayed just at the start of the Yellow !
Installed that on in my Intake Manifold (L-72 Winters Foundry) and with a 180 Deg. Thermostat, I can see the Temp climb over 180 and then settle down to Just above the Middle Mark, I will call that 180 Deg.
I also did a little Power Point/ Calculator Picture of what my Gauge will read.
It is Only what I think my car is at, while running.
1969 SS/RS Coupe 427BB 700R4 12 Bolt 4:11 A/C, High School Resto Mod
November 1968 Build Date