DIY Aetna Tach Bezels 5" -4"

This is the one for your engines.
Are these plug and play or do I need to get new senders?
plug and play. The sender counts the flywheel teeth using a magnetic pickup. So you just have to set the switches on the back of the tach to match the number of teeth on your flywheel. The tach comes with a lookup table that has that number on it, if you don't know it.
 
Here are the CAT and Cummins teeth counts from the Aetna manual.
 

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Are these plug and play or do I need to get new senders?


Plug and play. You need +, - and the signal wire. The old Teleflex have dimmable bulbs and Aetnas are an always on red backlight (my only complaint...wish the color was selectable and on/off/dimmable).

On the back is a set of very tiny DIP switches that you will need to set based on the number of teeth on your ring gear. Look at the back of your current tach and it will point to the right value. All these tach “count” teeth on the gear and convert to rpm.

The lighting wire will be your extra and you’ll need to secure it.
 
Plug and play. You need +, - and the signal wire. The old Teleflex have dimmable bulbs and Aetnas are an always on red backlight (my only complaint...wish the color was selectable and on/off/dimmable).
I agree about the backlights. Mine don't seem to be as red, maybe that's just the photos, but one of mine doesn't illuminate the hour meter as much as the other. It lights up and can be seen in the dark, but during the day looks as though the light is burned out for the hour meter. But overall, I love the tachs.
aetna tachs.jpg
 
I agree about the backlights. Mine don't seem to be as red, maybe that's just the photos, but one of mine doesn't illuminate the hour meter as much as the other. It lights up and can be seen in the dark, but during the day looks as though the light is burned out for the hour meter. But overall, I love the tachs.
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Interesting Mark. Like Dtfeld, neither one of my hour meters lights up. I guess I'll call Aetna and see what's up. Maybe it's a version thing and one of yours is an old version with a lit up meter. Also the picture from their website shows that the hour meter does not light up.
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I have run the Aetna tachometers for quite a few years now and have separate hour meters below, advanced to the proper engine hours. A friend got his shop to make polished aluminum trim adapters for me. Some day I might go for a new dash but this works well for now.
 

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I have run the Aetna tachometers for quite a few years now and have separate hour meters below, advanced to the proper engine hours. A friend got his shop to make polished aluminum trim adapters for me. Some day I might go for a new dash but this works well for now.

No sync gauge? Looks like that boat never had one?

I have engine synchronizer and it works like a champ, so wondering if I need a sync guage if I redo the panel.
 
No, the boat never had one. I just trust the Glendinning engine synchronizer to do its work and the two tachs are always within a few RPM.
Actually I don't think a gauge would get you any closer on synchronization, so why is it needed?
 
No, the boat never had one. I just trust the Glendinning engine synchronizer to do its work and the two tachs are always within a few RPM.
Actually I don't think a gauge would get you any closer on synchronization, so why is it needed?

I agree. I dont think have never seen a diesel SR without one...thought it was standard equipment.

I'm still trying to decide if I want to go all digital, and if I don't go with a sync gauge, thats more real estate on the panel.
 
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Here is a bit of red-neck knowledge on the Sea Ray gauge package.........the sync gauge is a panel filler on the 400/410. Usually the diesel versions were shipped with the sync gauge and without the engine synchronizer. Dealers ordered them that way because they usually were about $12K cheaper and Sea Ray threw in the sync gauge. The thought being they would be useful on boat that had to be sync'ed manually. My 450DA boat was ordered with a Glendenning synchronizer and it has never had a synch gauge. In some 30+ years of running various Sea Rays around Florida, I have never seen a synch gauge I could depend on........you might be able to sync the engine with the gauge, but when you look at the gauge, it is pointing to one engine or the other but never centered.

As far as all digital, I wonder what that gains you on a boat with analog engines, no ECM, and analog senders since the senders are the data source for everything your gauge package reports...........and the 3116/3126 gauge packages are notoriously accurate.


Frank
 
I have the synch gauge and don't have the Glendenning synchronizer system. Here's a related post regarding centering the synch gauge. Both my analog tachs and synch module were quite a bit off, without me realizing it. Now, both are tuned accurately. I use my synch gauge all the time as I accelerate, to keep the two engines close in rpms. Once I level off I match up the two Aetna tach readings. I find the synch gauge quite useful for the way I like to operate the boat. I don't seem to have the ear to "hear" correct synchronization of the two engines, so accurate rpm and synch gauges work well for me.

http://clubsearay.com/index.php?threads/official-cummins-6cta-450c-thread.77886/page-24#post-1085327
 
Here is a bit of red-neck knowledge on the Sea Ray gauge package.........the sync gauge is a panel filler on the 400/410. Usually the diesel versions were shipped with the sync gauge and without the engine synchronizer. Dealers ordered them that way because they usually were about $12K cheaper and Sea Ray threw in the sync gauge. The thought being they would be useful on boat that had to be sync'ed manually. My 450DA boat was ordered with a Glendenning synchronizer and it has never had a synch gauge. In some 30+ years of running various Sea Rays around Florida, I have never seen a synch gauge I could depend on........you might be able to sync the engine with the gauge, but when you look at the gauge, it is pointing to one engine or the other but never centered.

As far as all digital, I wonder what that gains you on a boat with analog engines, no ECM, and analog senders since the senders are the data source for everything your gauge package reports...........and the 3116/3126 gauge packages are notoriously accurate.


Frank

I have no sync gauge, but a switch that engages the sync. The port throttle becomes the slave and both engines are operated with the starboard throttle. Tachs always read with identical RPMs.

Bennett
 
I'll have to look at the sync gauge and see where it centers/adjust as necessary.

Now that you mention it, I use the sync gauge while coming up on plane, so I'll keep it, but looks like there is a smaller version.
 
I have no sync gauge, but a switch that engages the sync. The port throttle becomes the slave and both engines are operated with the starboard throttle. Tachs always read with identical RPMs.

Bennett
Bennett - I had both the Glendenning sync and the gauge on my 410. The Gendenning worked perfectly as you describe.
 
I heard back from Aetna. Here is the response: "It is possible that the unit that has the red is coming from the backlight for the RPM display. We do not add any backlighting for the Hourmeter, but we do not mask it from the other backlight."
 
Ha, I had actually wondered if there was something wrong with the hour meter light on the port side, and because it was so faint, thought maybe it was just getting a little light from the RPM light. At least now I know that that's not the case. Thanks.
 
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I'll have to look at the sync gauge and see where it centers/adjust as necessary.

Now that you mention it, I use the sync gauge while coming up on plane, so I'll keep it, but looks like there is a smaller version.
Based on what others have said, I was lucky I guess that my old tachs and sync gauge were fairly accurate. I do not have a synchronizer either so I was never really sure until I put in the Aetnas, but the sync gauge is right on at the lower rpms and off just a tiny bit at wot. Not enough to bother to adjust imo.
Hopefully you’ll be lucky and not have to adjust it also.
 

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