Lucas1

i have the 3788 autometer..

the sticky has a wiring diagram but isnt clear on wire colors from what i see
the alternator pickup method is bs and has never read accurate. i want to wire it to the factory plug.


ALL I CAN FIND IS HOW TO WIRE THE ALTERNATOR PICK UP AND THER IS SOME ERROR WITH MY FACTORY TACH PLUG HAVING A BLACK 12V WIRE WHERE ITS STATED IT SHOULD BE BLACK.

the autometer tach has two wires going to the pick up.

black and black/with white stripe..
rest of the tach is hooked up ie switched power/dash.

factory plug is

black
orange
black
grey...........................................is this the one for the signal?

wiring diagram say LB is that light blue??maybe thats what the grey is.....just faded

9MM

LB would mean light blue but if I'm not mistaken you gotta use a isspro gauge through the factory plug.

Lucas1

SO SOMEONE WITH A CRAPPY AUTOMETER TACH IN THERE TRUCK USING THE FACTORY PLUG PLEASE RESPOND.

and for the record i have no idea how you guys got the alternator pick up to work.. there is no room arond the alternator and i tried numerous positions............all the tach does is bouuce then move to 1500rpm any pics?


maybe my tach is fualty

9MM

Try this

http://www.cumminsforum.com/forum/89...93-trucks.html

Also I have a alternator mounted Autometer tach on my truck ifd the sensor on the alt is loose it will jump around.

Lucas1

ok now with the autmometer guage it has the two wire off the tach for the alternator i tied putting the black wire to the grey factory signal and got nothing..

iam not sur e..and dont want to cook the pcm

Bencie

Lucas I also have the autometer tach and like it. I used the alt pickup and in the factory plug under the dash, I used the power wire and the light wire. I used a hand held photo tach with the reflective tape to adjust the tach with. I don't remember the colors but I got that info from the sticky, mine is very accurate and I like it alot. good luck.

Lucas1

maybe i have a bad pickup. where on the alternator did you put it exactly...right above the windings that are visable or inbetween ?

maybe my alternator is not stock as a have no laminated section it attach it too as described in the instructions.

BearKiller

If you have the tachometer sensor that clamps on the exterior of the alternator, the best advice I can give is to NOT USE that long metal hose-clamp and use a big long ziptie instead.

I have read that the tach works best when the sensor is clamped as close to the 10-O'clock position as possible.

If the alternator has a "seam", you want the sensor straddling that seam.

Lacking a visible seam, I would try it with the sensor over the alternator's centerline.

If I still wasn't getting a satisfactory signal, with engine running, I would have someone watch the tach while I maneuvered the sensor around on the alternator; --- >>> DON'T WHACK OFF YOUR FINGERS <<<.

BearKiller

While we are on the Autometer tach subject, I have an old one that is very similar to that being discussed.

The tachometer portion works fine.

However, a few years ago, the silly illumination light quit working, as in maybe the bulb shot.

I have made several attempts to get inside the tach to access the bulb.

Nothing I have tried has let me in there.

It is like they put all the guts together, including the bulb, and then sealed it all inside an impregnable plastic casing.


Does anyone else have this tach and how on earth does one access the bulb ??

Thanks.

Lucas1

ill try again......

but ive had that darn thing in every spot.


is there no way to hook this up to the factory connection?

there is two wire going to the alternator pickup.Wonder if you can use one of the wires for the ECM signal.

i just dont want to damage the ECM ...wich i hear can be done

BearKiller

The factory-wired sensor/tachometer and the external alternator sensor/tachometer are entirely different animals.

I highly doubt that the two are compatible and very likely you would damage the electronics within the tachometer if you tried.


There is even a third type electronic tachometer like that in the wife's truck; VDO if my memory serves; that which there is a single sensor wire that ties INSIDE the alternator to one of the three phase terminals.


Then, of course, if you want a real tachometer, there are the cable-driven fully mechanicals.

Bencie

No laminated area on mine either, I put the pickup under the top mount so it wasn't visible, the big hose clamp is still visible though.

9MM

Here's a pic of mine mounted on the the alt.


I think I have that same tach as mentioned above by bearkiller.

BearKiller

9MMs pickup/sensor looks identical to mine.

My alternator DOES have a seam though, thus my sensor is oriented 90* to the way yours is.


I wish someone could enlighten me as to how to get at the illumination bulb.

Lucas1

ok i had it there .........my alt look the same . ill try again tommorow.


by the way

thanks for posting that up

ps did you have a hard time calibrating yours?