Adding a tach to a '94 GTS

[Dougsnash]

I have a '94 GTS that is working well but I am running with two turboed Aquatrx and am therefor always trying to keep up (40mph with a tailwind vs 60+). I have a tested spare tach from a '95 XP that I am trying to install into the hood gauge pod so I can run at the max efficiency/power speed. I have run gauge power and a pulse line up into the hood but I am not getting the tach needle to move.

The power is tied into the MPEM on the appropriate lead and the ground is to the ground lug at the coil so the power side of the setup should be okay. When I fired up the engine at idle for a few seconds I am seeing about 10.5v which should be enough. I do have a question about the signal that ties into the AC side of the voltage rectifier/regulator. The wiring diagram in the manual I have for '94 (all models) has a diagram for the XP with a tach and shows it connecting through a 20 kOhm resistor to the yellow/bk lead on the AC side of the rectifier. I didn't have a 20 kOhm so I used the closest I had, 22 k Ohm. Is the resistor actually needed? Is the 22 kOhm just too big?

I know the tach is good because I tested it on my '95 Speedster this afternoon and it works fine. Obviously the problem has to be with the way I have the signal connected to the regulator/rectifier. Or at least that is how I see it.

Any suggestions?

Doug M

 

[Dougsnash]

As an addendum to the tach I am working on, I just finished installing a fuel gauge on my old GTS. I installed a fuel pickup that has the sending components installed and a used fuel gauge from a '93 GTX. I also have the oil level float to install next time I have the oil tank loose but for now only the fuel portion of the gauge works.

Hmm, if I were to build up one of the 657Xs I have as spare cores for my boat to throw in the old GTS, I'd essentially have a GTX. Maybe I wouldn't need to upgrade to a four stroke to keep up with the Hondas after all.

Doug