electric vs mechanical (old style) temp gauges

Pat Martone

Pat Martone

Senior Member
Are there any issues with installing an electrically-driven temp gauge, requiring an electrical sending unit and 6v (or 12v) power from the ignition.

I am guessing one of the advantages of the old style mechanical gauge is that it keeps indicating the temp after the ignition has been turned off.

Any other pros and cons that are worth considering?

Thank you.
 
If you're going to use the dual (oil/water temp) gauge like in Snyder's catalog i don't see any issues except it won't look "period". JMO
Paul in CT
 
You cannot connect an electrical temp gauge to the ignition switch on a stock Model A as you would be putting the gauge in series with the coil and in parallel with the points. You can connect it up to its own dedicated switch, however, you will have to remember to shut it off when through driving or you will run the battery down.

Tom Endy
 
CarlG said:
Tom, Does that hold true when using the NuRex ignition switch with an ACC terminal?
Click to expand...


Sorry, I can't answer you question as I do not know how they are wired into the Model A electrical circuit.

I am a firm believer in leaving the Model A ignition system exactly as Henry designed it. Over the years I have witnessed just about all of the "modern" modifications and seen all of their failure modes. It is a simple circuit and there is little that can be improved on.

Tom Endy
 
Yes, I do understand that it won't look "period" correct.
I am considering installing under the instrument panel, both a matching 2" water temp (50-220 degrees) gauge and tachometer (0-3500rpm) gauge, both from Westach.com. I wanted the two gauges at least to match each other, otherwise I would have used the Rex A Co (APCO) mechanical temp gauge which is closer to the Model A vintage.
My original pop-out ignition broke a while ago and I replaced it with the $20 version which has a very thin cable going to the distributor. I assume this set-up also precludes me from wiring the temp gauge to my ignition switch?
If I wire-up to temp gauge directly to the battery with a simple toggle switch, I can't imagine there would be much of a current draw that would kill my battery too quickly if I forgot to turn the switch off?
 
CarlG said:
Tom, Does that hold true when using the NuRex ignition switch with an ACC terminal?
Click to expand...

Connecting it to the ACC terminal solves the problem, in my experience.

Pat Martone said:
... I can't imagine there would be much of a current draw that would kill my battery too quickly if I forgot to turn the switch off?
Click to expand...

As I recall, it took a few weeks or maybe a month for my electric gauge to drain the battery to the point where it would not start the car. I believe it pulled about 5 milliamps. Connecting it to the ACC terminal on my modern ignition switch solved the problem.

Steve
 
Thanks, Steve.
Unfortunately, I do not have an accessory portion of my replacement ignition.
I suppose I will have to connect both gauges directly to my 12v battery and use a toggle switch.
 
steve s said:
Connecting it to the ACC terminal on my modern ignition switch solved the problem.
Click to expand...
Steve, Do you recall which "modern" ignition switch you used? And does it fit the original space or did you mount it elsewhere? Thanks, Carl
 
connect to connection box on firewall only one side is hot with switch off ,otherside is hot 24 /7 chect with meter to make sure you get the right post
 
CarlG said:
Steve, Do you recall which "modern" ignition switch you used? And does it fit the original space or did you mount it elsewhere? Thanks, Carl
Click to expand...

It was Universal brand, I'm pretty sure. Don't recall number. I think I got it from NuRex when I got their electronic ignition 15 years ago. It fit the original hole and space perfectly, and looks fine, to my eye. I recall seeing one that looked just like it on a rotating display thingy at an auto parts store not too long ago, but I think the usual A suppliers all carry them too. Whatever you do, don't cheap out; buy the most expensive one they're selling. I've had to replace 5 of the cheapies in my career, and finding their intermittant failure source can make you crazy!

Steve
 
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