75 FXE Tach Wiring
Bob Kaspar
other years. I am tring to get my tach to work but don't seem to have
the right regulator(According to the HARLEY Shop manual the wiring
should come off the regulator with a pink (On A HARLEY ???) wire.) But
the regulator I have does not have this wire and when I called 2
different shop they told me they know of no difference in tach between
1975 and other years that hook up to the ignition coil terminals,I would
like to try hooking up to the coil but am wondering if I will do damage
to anything.If you have any experience with these tach let me know!!
Thanx--> Bob
dennis.a.truxal
Hey Bob -- tell those "shops" to read their own manuals!! You are
correct -- there *is* a difference.
'74 and '75 FXE tachs get their signal from the alternator, the
nature of which is a pulsed AC voltage.
'76 and later FXE tachs get their signal from the coil, which is
a pulsed DC.
HD part#92040-74 is tach for '74 and '75, uses pulsed AC.
HD part#92040-76 is tach for '76 and later, uses pulsed DC.
HD part#74510-70A is regulator for '75 and earlier (has extra wire).
HD part#74510-75 is regulator for '76 and later (no extra wire).
I ran into this same problem about ten years ago when a friend
bought a tach at a swap meet for his Sportster. When it didn't
work, he gave it to me to trouble-shoot. Turned out to be one of
those AC tachs. The only way I got it to work on the bench was to
use a 12 volt filament transformer as a source and pulse it through
a buzzing relay. Using a 12 volt DC power supply and the same
buzz-box got me nothing.
HOWEVER ---- Months after I returned it, the friend said he put it
on his Sportster and wired it to the coil, and it was working. I
didn't have any answer for this. Try it for a short test and see
what happens; I don't think it will do damage. If it's not going to
work, it will just sit there and stare back at you, in which case
you will have to locate the correct regulator/rectifier or get a
later model tach.
Good luck -- let me know how you make out.
Dennis A. Truxal
R. E. S.
(dennis.a.truxal) wrote:
===snip===
> HD part#74510-70A is regulator for '75 and earlier (has extra wire).
> HD part#74510-75 is regulator for '76 and later (no extra wire).
===snip===
Hey Dennis...
You are correct, but there is a bit more about the regulators. The
early alternators were a "four" wire configuration. They used a TOTALLY
different means of regulation to control the output. The newer alternators
use only two wires, and that's when HD switched over to an ignition driven Tach.
Stroker Ray
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
'55 Custom Hardtail + I don't try to explain why I ride a Harley +
'75 96cid FXE + For those who understand, no explanation is needed +
+ For those who don't, no explanation is possible +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>>>>>>>>>>>>>> LIVE TO RIDE..... RIDE TO LIVE.... <<<<<<<<<<<<<<<<<
Ron Jacksha
: Does anyone know of a difference between 74 & 75 FXE tach wiring and
To the best of my knowledge all the FXE tachs work the same. (I don't have my
manuals here.) There should be two terminals on the back side of the tach. One
will be marked IGN and the other marked TRG. The IGN terminal connects to the
battery (or ignition) side of the coil and I do believe this wire was pink on
my FXE. The TRG terminal connects to the point side of the coil. If I remember
correctly this wire was white.
If the tach still doesn't work, make sure it is well grounded. The ground for
the tach, the tach backlight and the speedo backlight are all the same. On FXE's
it was a single wire that ran from one of the gauge brackets to a screw on the
upper triple tree.
That's all the info I can give you without one off my shop manuals. Good luck!
------------------------------------------------------------------------------
Ron Jacksha |
Hewlett-Packard Co. | In the wind
Spokane Division | If I have to explain,
(509)921-3238 | You wouldn't understand...
jac...@spk.hp.com |
------------------------------------------------------------------------------