Bench test a Tach with a Battery Charger?

**Luva65wagon** · January 31st, 2012, 08:40 PM

I go every year. It is the big one at that location; about the same size as Monroe, maybe 25% smaller. I like it because it feels a bit less disjointed to maneuver to each booth. I never leave there feeling like I didn't get to see every vendor.

**BillP 98201** · February 1st, 2012, 07:22 AM

Im going also. Maybe someone could show me how to bypass this later.... Maybe on the tech day.

**Luva65wagon** · February 1st, 2012, 10:55 AM

Originally Posted by BillP 98201

Maybe someone could show me how to bypass this later.... Maybe on the tech day.

Does anyone have a wiring diagram for a 63 Sprint with the tach option? If so, it would be easy to draw up a plan for the bypass.

**64SprintV8** · February 2nd, 2012, 09:47 PM

Will these suffice?

https://skydrive.live.com/redir.aspx...IJEZGcNSt5Xbv8

**Nathan289** · February 2nd, 2012, 11:05 PM

I'd be very careful testing a sprint tach.. I don't think they are designed to see a full 12v. Kinda like ford points

Some of the very old sun pro tachs needed a box to make them work. With out the box you had a cool looking dash orinment (sp?)

Autozone sells the new sunpro II and they are like $30 probably made in china.

Hopefully you'll find some vintage tach at the swap.. I found a cool auto gauge tach that was still in the box.. it had been opened but never installed.. its sitting in the garage still not installed..

Nathan

**Luva65wagon** · February 3rd, 2012, 11:22 AM

Originally Posted by 64SprintV8

Will these suffice?

https://skydrive.live.com/redir.aspx...IJEZGcNSt5Xbv8

That might help. Pretty fuzzy, but I'll study them closely. Gracias.

**64SprintV8** · February 19th, 2012, 10:33 PM

******************* U P D A T E ***********************
I verified that the battery charger test does work.

Basically, hook all wires to power and the remaining black wire to ground/negative. Attached are some pictures. The new tach is showing 1,800 RPMS as anticipated. The others tested bad and are just there for reference. Oh, and I am not keeping the white face tach, it was just for testing. That is why the wires were carefully removed from the back of the packaging.