Tach causes stall ...ideas? (1 Viewer)

[Cougar72]

I was trying to put my dwell/tach/meter onto my rig to set the idle... (I had always previously just set it by ear)...

...and as soon as I connect the lead to the coil neg wire the tach needle goes up to about 500-700 RPM ish (not enough time to read it) and then the engine dies immediatly... if I yank it off fast it may recover and idle as normal.

I wondered if my tune/tach was bad, so I tested with an old Sun-tach that I had in a box - same symptom: Stall

2. Any Ideas as to why the stall?
3. Is there another place to attach the tune/tach

In general everything runs fine - but its frustrating that I cant hook up a tach

 

[numby]

Try connecting to the battery post.

 

[gisham]

there must be another issue...i just connected my tach to the - and it works great...