Champion Model T Spark Plug Tester

[bron-hertford-nc]

Searching for wiring diagram and source for replacement transformer ( 110V, 60 cycle, 15V, 25 watts).
Have template for the 'Change Every 10,000 Miles' - an easy fix.
Bron Prokuski 703-346-7510 cell

[Mark Gregush]

Could you buy one of the ready-made 120 volts AC to 12 volt DC adapters and install inside? Is there a motor inside operating a set of points with drop down resister to the coil, motor needing the 15 volts, or is it continuous fire when you press a button? Does it have a standard 6 or 12 volt coil inside?

[bron-hertford-nc]

Thanks for the inquiry. It is a step down transformer that activates the Model T coil to fire the spark plug.

[Dan Hatch]

Just an idea. My new DRO came with a small 15VDC power supply. Not sure about watts. But the T coil should not care if it gets AC or DC .

[Mark Gregush]

If it is just firing a T coil, then I would think that an off the shelf 120 to 12 volt adapter should work just fine or even the guts from an older model train transformer that didn't have a reversing switch, maybe could be adapted. With the model train transformer, you could adjust the voltage and check how the plugs fire under low voltage conditions.

[Steve Jelf]

Bron, after receiving your email asking about a transformer and where I got it looked for some record of both and found nothing. So after being reminded by your post this morning I had the brilliant idea of actually looking at what I have.

This is the tester as it came to me. It was an extra that Dean gave me when I stopped at his place on my way home three years ago. It was a Hershey find.

Here I have cleaned up the inside and installed a new power cord. The original 1932 transformer is still there, but I had to replace it after one of the terminals broke off and I was unable to fix it.

Here's a current picture with the "new" transformer in place. It's obviously an old one. Unfortunately I have no memory or record of where I got it. Maybe I bought it online, or maybe it was a donation, or maybe I found it in my extensive collection of junk. It has four leads. The white wire in goes to one of the two primary leads. The black wire in goes through the button switch to the other primary. The line power in is the standard 110 volts AC house current. I assume the two secondary leads are 12 volts, but I can't say for sure. One goes to the top (timer) contact on the Model T coil. The other goes to ground on the case. So does the coil's bottom contact.

The restored tester with a new air pressure gauge and regulator.

[bron-hertford-nc]

Good ideas - I still do have my Lionel train stuff from the 40s. Will see what else pops up on the Forum. Anybody that has one, a shot of the internals would also be helpful so I can cross check my wiring.

[bron-hertford-nc]

And thanks Steve - liked your answering machine message!!
Bron

[Steve Jelf]

I never thought of it, but I expect a model train transformer would work just fine. Ideally it would fit inside the case, but I suppose you could use it externally if it's too big. One wire would go to the coil's top (timer) contact, the other would go to ground on the tester case, and a third would go from the coil's bottom (strip) contact to also ground on the case. Of course the spark plug wire attaches to the lower side contact on the coil.

[Mark Nunn]

The doorbell in my house has a transformer with three output voltages. I believe they are 9V, 18V and 24V. It converts from 120V. That might be easier to source than something more rare.

[Steve Jelf]

Of course! Why didn't I think of that? Perfect.
https://www.google.com/search?q=doorbel ... nt=gws-wiz

[david_dewey]

Steve, your "new" transformer looks suspiciously like an old doorbell transformer!!

[TXGOAT2]

Avon Calling....

[david_dewey]

Steve, your "new" transformer looks suspiciously like an old doorbell transformer!!

[Luke]

An old 6.3VAC filament transformer would work fine. Should be lots of things around with them in.

This'd be close to 9V peak, you don't need 12V and it may be that a lower voltage would show up a weaker plug more easily?

BTW - nice resto job Steve!

[bron-hertford-nc]

Thanks for all inputs.
Turns out original transformer not blown - so working fine. Have contacted a number of firms with the specs. Awaiting reply.
The champion decal is below for those interested. Contact me w your email and I will send you the master - you can then change colors at will on your computer, print it out and paste.

[Steve Jelf]

Being curious, this morning I Googled this type of tester. The cheapest one I found of this vintage was priced at $125, and it was pretty rough. Some in better shape were $350 and $400.