Replacing rev counter display - E32-3 (Tach)

[nquigley]

My rev counter has been twitchy for several months - sometimes needing a tap to get the needle to wake up, and sometimes it comes on by itself after 5-10 min of motoring. But, now it seems to be dead. It's receiving power - the backlighting is working. I've checked the connections behind it (all were tight and not apparently corroded) and I added some electrical contact cleaning fluid for good measure, but all to no avail.
Any ideas where can I get a replacement rev counter that will fit in my OEM gauge panel?
Also - how can I verify that the alternator is actually sending the info the rev counter needs?
Thanks!

 

[Prairie Schooner]

Sorry, I've led a really sheltered life. What is a "rev counter diusply"? Is that another term for a tachometer?

 

[G Kiba]

Some choices from Defender (no affiliation).

https://defender.com/en_us/catalogsearch/result/?q=diesel%20tachom

 

[Loren Beach]

I hope I am not leading the discussion astray too far. However, gotta say that I have adapted well to the "modern" digital display for our club's Cat diesel in the bigger dredge we bought in '15. At first I missed the analog dial in the old dredge (John Deere diesel), but now kinda like the monochrome screen just as well. That screen has all the temp and pressure info displayed also.
Of course this is really an "industrial" sort of item and the display is sharp and well lit.
These might be expensive or really not a drop-in change for our older engine panels, admittedly.
Anyhow, just mentioning it because it's out there.

Silly Aside: I DO sometimes miss the former legacy cable-controlled throttle pull... ! Adding/decreasing RPM's with an electric bat-handle switch is zero Fun... compared to the direct throttle link we had before.
Before the main pump is clutched in - i.e. no load, we can no longer give the big ol' knob a quick pull and make 'er bark and put our a puff of smoke...

 

[nquigley]

Some choices from Defender (no affiliation).

https://defender.com/en_us/catalogsearch/result/?q=diesel%20tachom

Thanks!
They seem to have 4” diameter gauges - I think mine is only about 2.5” diameter
I left the boat today (for 2 months) but forgot to photo and measure the gauge - a friend will do that next week

 

[Christian Williams]

The stock panel of the 32-3 is depicted here, along with the number of the replacement tach I installed.

E32-3 - Universal M25 Engine Wiring Upgrade Part 1--Cockpit Gauges

Why bother? Well, twice last year my M25 diesel wouldn't start up again after being turned off. I could jump the solenoid with a screwdriver--if there was someone in the cockpit to hold down the paired glow plug and starter buttons. When it...

ericsonyachts.org

 

[G Kiba]

Thanks!
They seem to have 4” diameter gauges - I think mine is only about 2.5” diameter
I left the boat today (for 2 months) but forgot to photo and measure the gauge - a friend will do that next week

There are several standard sizes. Measure what you have and go with that. They come with instructions that I tried to follow (for a rotating switch settings) but I ended up just using the setting that gave me the best or closest rpm at idle. Seems to work great! Not sure how accurate, but enough to gauge a good crusing speed and peak rpm.

 

[Prairie Schooner]

Sorry, I've led a really sheltered life. What is a "rev counter diusply"? Is that another term for a tachometer?

Thanks to whoever revised the thread title. I constantly feel like I have so much to learn and was genuinely curious. I wouldn't be surprised to be told there was a remote chamber with a flux capacitor and muffler bearings that I should have serviced years ago.

 

[JSM]

I ended up just using the setting that gave me the best or closest rpm at idle. Seems to work great! Not sure how accurate, but enough to gauge a good crusing speed and peak rpm.

When I replaced mine I dialed it in with one of these.

https://www.amazon.com/Digital-Photo-Laser-Tachometer-Contact/dp/B001N4QY66/ref=sxin_16_pa_sp_search_thematic_sspa?content-id=amzn1.sym.27b41115-b206-47c3-8621-713097e8442c%3Aamzn1.sym.27b41115-b206-47c3-8621-713097e8442c&cv_ct_cx=handheld+tACHOMETER&keywords=handheld+tACHOMETER&pd_rd_i=B001N4QY66&pd_rd_r=c6a6c0e2-e6ac-4503-bb8d-319cfedf8bd2&pd_rd_w=Gu5Yb&pd_rd_wg=pgSYn&pf_rd_p=27b41115-b206-47c3-8621-713097e8442c&pf_rd_r=FRERKYT9NS7XV6RKAJAV&qid=1734100048&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=1-2-6024b2a3-78e4-4fed-8fed-e1613be3bcce-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&psc=1

 

[G Kiba]

When I replaced mine I dialed it in with one of these.

https://www.amazon.com/Digital-Photo-Laser-Tachometer-Contact/dp/B001N4QY66/ref=sxin_16_pa_sp_search_thematic_sspa?content-id=amzn1.sym.27b41115-b206-47c3-8621-713097e8442c%3Aamzn1.sym.27b41115-b206-47c3-8621-713097e8442c&cv_ct_cx=handheld+tACHOMETER&keywords=handheld+tACHOMETER&pd_rd_i=B001N4QY66&pd_rd_r=c6a6c0e2-e6ac-4503-bb8d-319cfedf8bd2&pd_rd_w=Gu5Yb&pd_rd_wg=pgSYn&pf_rd_p=27b41115-b206-47c3-8621-713097e8442c&pf_rd_r=FRERKYT9NS7XV6RKAJAV&qid=1734100048&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=1-2-6024b2a3-78e4-4fed-8fed-e1613be3bcce-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&psc=1

Very cool and affordable! Turns out the tachometer only had two of the settings that even registered a reasonable rpm. So I picked one of them after running the throttle up. It would be nice to confirm the readings someday. Thanks.

 

[Christian Williams]

That's the highly scientific way I do it. Whatever gives Idle about 800, top rpm about where manual says. I have checked with a $20 optical tach and the numbers are about the same as the guesswork.