Location on 480CE engine for Aetna teeth counter sender

[Douglas Fairchild]

Trying to find location for mounting Aetna Teeth counter sender for their Tachs on a Cummins 480CE engine. I saw two electrical hook ups on left side of bell housing. They are already being used by other components although I do not know for what. Maybe the analog tachs are using one for the present tachs which I am removing. Any help would be greatly appreciated. A photo would be great. Doug

Topic

[Douglas Fairchild]

Splitting signal on tooth counter

I put three hours on engines since I wired tachs and no problems so far. Sensor on left does go to smart craft and although not accurate it also works fine.

[pwrobert]

Magnetic sender hookup

Magnetic senders are not like regular senders used for oil pressure , engine temp, etc where the senders are setup for a specific number of gauges – single station or dual station with specific OHMs output. They are essentially An on-off Switch. While there may be a limit to the number of devices attached to them I’m not sure what that is. What I do know is that one sender can support a signal for several tachometers. Before I repowered with 6 BTA’s I ran Detroit engines and both engine types only have one magnetic tach mounting hole.
The grounds and signal+ wires are run to positions on my wiring buss and I have three tachometers reading the signal with no issue. One Teleflex analog sender, one digital tachometer, and one hooked to a Noland RS11 so the tachometer info goes to the NMEA 2000 network.

I suspect you can split the signal in your case as well. Since you have two senders I’d pick the one that doesn’t go to the Smartcraft to share as they are the “dumbest” instruments and likely not as picky about the sharing.

[Douglas Fairchild]

Instructions for hooking up Aetna Tach to 480CE

The three wires on teeth counter sensor are red, voltage +, Yellow, teeth counter signal out, Black, teeth counter return. I wired wires parallel to plug wires leaving the red voltage wire as is. So far it works fine. On Cummins schematic yellow wire marked as blue. I used teeth counter on left to tap off of.

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Rob Schepis

[Douglas Fairchild]

Aetna tach Stll not working

Well apparently there is only a signal wire going to the VDO tach. Aetna says you can run a ground wire from engine block to tach but not recommended due to engine noise causing erratic RPM indications. Aetna senders have two wires coming from teeth counter. Cummins has three wires. Ordered 480CE wire schematic from SB. Hopefully with schematic I can figure this out.

[Douglas Fairchild]

Left sensor identified

Unplugged sensor in photo on the left and my smart craft rpm display went blank. Obviously this is the magnetic sender. The second is probably for the VDO tach which does not work. I am going to order Aetna tach and wire signal line and – line which went to original tach and hook up Aetna tach and it should work. Doug

[Douglas Fairchild]

Photos requested

Hi Tony

Here are the photos, if I am missing anything let me know. Photo 1 shows the back of the VDO tach. I have the wire connections schematic if you need it. Photos 2 and 3 show the two what maybe the magnetic teeth sensors. I have a 450C shop manual and these are in the area of where they are on that model. They do not look like it because there are two whereas the 450 has one. Further there is no way to adjust the height of the sensor like on the 450. Photo 4 self explanatory. Photo 5 is the base of the starboard tach with wire connections. Photos 6 & 7 show the smart craft displays. Photo 8 shows helm over all. I have all gauges along with smart craft so there are two gauges of everything. I will probably get rid of all the VDO redundant gauges. Thanks for all you help. Doug

[Tony Athens]

Send or post very clear pics of the senders on your engine now.

What are they used for? Send pics of the dash/helm station

If you are dumping your current analogs, the Aetnas can use that signal–You do not have to you “aetna senders”

[Author]

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