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Vans Tachometer

Hello -

My Vans tachometer (see picture) has recently become intermittent and was wondering if someone can offer some insight. I called Vans and was told they no longer sell these. Does anyone know who originally manufactured these tachs and if someone rebuilds them? I believe it is 2 1/4" in diameter.

Thanks!

Andre'
 

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I have a Vans tach, new in the box never installed. PM me if interested. I also have new in the box Vans AMP, 15 psi fuel press, CHT, and EGT.
 
The more common problem with these tachometers is not the instrument itself but rather the sending unit. Especially if the sending unit is attached directly to the accessory case of the engine.

I had two of them fail in quick succession. Then I smarted up and bought a 12" tach cable from ACS - this allowed me to remote-mount the tach sending unit to a clamp on the firewall. That was at least a decade ago with zero problems since. The tach senders don't seem to like either the heat or vibration or both when attached directly to the engine.
 
Vans Tach

The tach is connected to the P-Lead on one of my Bendix magnetos. I just completed a panel upgrade - after starting the engine (the 1st time since the upgrade) and seeing no RPM's displayed on the unit, I discovered I had reversed the Sender & +12V connections on the back of the tach. After correcting the wiring, the tach is now intermittent - sometimes indicating RPM's and sometimes dropping to zero - while the engine is running. When it does display RPMs, the reading changes when I adjust the throttle. I also had both mags rebuilt/overhauled while I was upgrading the panel. At this point, replacing the tach is about all I can think of to correct this issue.

Andre'
 
I've found either the Tach (gauge) works, or it doesn't. If intermittent, the issue was always the input. I'd re-check the P-lead connections again, anything that might have been touched of moved during your panel renovation.
 
Do you have an old car tach tool you could hook up to determine if it's the tach or the wiring to the tach?
 
I plan to work on this issue later this week with my IA. Troubleshooting a possible intermittent wire connection (P-Lead?) with the engine running will require more than one person. If that doesn't reveal anything, I will try a 2nd tach as recommended - thanks Ed!

Andre'
 
After testing, both gauges appear to be toast. I am in need of a VTACH3500 tach and a UMA 7-100-20 Manifold Pressure gauge (both are 2 1/4"). If anyone has one they can spare, I would appreciate a post!

Andre'
 
I think I might still have a tach, let me check at the hangar.

Bob. Burns
Rv-4 n82rb
 
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