kalli

Hi lads,

another great day and lots a money wasted for nothing.

I bought an aftermarket rally pac from Sacramento Mustang a year ago, that I hooked up inline with ignition the way it should be and that worked fine.
Ignition+ --> rallypac in/out --> coil+

i never really liked it as it would disable ignition when tach in rally pac dies, but no problem.

So then I upgraded to Mallory electronic ignition. Hyfire iV with unilite distributor and everyone told me the Rally pac will not work that way and everyone was right.
The signal on coil+ is to weak to trigger the series tach. So I bought the expensive mallory tach adapter that will connect to tach output adn pull a few mA from coil+ to help the tach trigger. didn't work for me. I have a suspicion my tach output on mallory box is fried.

Now I said **** that and just gave it a try and hooked the rally pac in such a way:
one connection to ground, the other to coil- .... and ... IT WORKS!!!!

I cannot say if that is the case with the original Rally Pac as well, but with this one, no problem. I cannot believe it ... Happy days in Ireland again.

Kalli

kalli

i thought ... I checked tach against good known gauge and rally pac shows about 15% more then real. there's an adjustment screw but i'm already the full way. any more turn will set it even more off.
If noone else has any better idea, I'll probably try with a resistor in the line. I'll buy a few ones, 50Ohm, 500ohm, 5kohm. maybe just get a poti ... I'll get back when I have a solution .... but as said the good news it's working ..

gothand

Me thinks you need to look at the instructions again for the tach adaptor. I've used RP's with MSD ignitions and tach adaptors. Double check the instructions to make sure you are wiring it up for a current driven tach.

Good luck!

kalli

i think the tach output on my mallory box is fried, not giving any signal. I believe it should be a square pattern 12V but have no osci to verify. I'll just see if i can read any voltage output at it. the voltmeter should show somethign at idle.