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Hooking tach to 80 series alternator?

Posted: Thu May 20, 2010 12:01 pm
by nicbeer
Can it be done with no internal alternator mods. I have got hold of a diesel tacho that is meant for the alternator not injection pump. Auto-Gauge brand

Mines a std so does not have the inj pump output for tach.

AFAIK std Denso alternator, pic below for reference.

Image

thanks

Posted: Fri May 21, 2010 3:07 pm
by nicbeer
hrmmm so noone has done it before

Posted: Sat May 22, 2010 9:18 am
by killalux
Is quite easy to do, Just undo the the nuts on the main power stud and the 3 8mm nuts holding that back cover on. Once off you will see 4 screws around tyhe outside of the rectifier (come in from the side) You can then just attach your tacho wire to one of these. Note 1 of those wires will be a star point, so will not give the correct signal. not sure which one it is. so if it doesn't work change it to another point.

Another note, tacho driven off the alt will generally note read 100% correct. because it is not driven at 1:1 ratio from the crank.

Steve

Posted: Tue May 25, 2010 5:10 pm
by yamaha12
howd u go with it?

Posted: Tue May 25, 2010 11:10 pm
by nicbeer
Yamaha, only just seen updated post.

Killalux, cheers for the info, will be trying this soon, i am guessing that if u take the plug out of the back and mine power this can be done in situ?

can the alt be run without the rear cover one for testing?

Posted: Wed May 26, 2010 8:35 am
by killalux
should be able to do it in place, may just be a bit tight.

you will be able to run it with rear cover off, however just put one of the nuts back on the studs coming out the back so that the rectifier still gets a good earth.

Steve