Tachometer amplifier / Tach connected to coil engine dies

[TuffleHunden]

Hello everyone, been a couple of years. I have a stumper for me. 1996 Volvo penta 5.0 FL PHUE / ford 302. I rebuilt the engine and all is well except that I have a little problem with the tach. Well I had a problem getting the engine started at first. Could not get any spark from distributor to plugs. Then it went to no spark from coil. I replaced the coil and Ignitor hooked it all back up and no start. Turns over great. So I went to the basics and disconnected all but necessary from coil, the only wire that was actually disconnected was the coil wire from the neg side of coil. Bam started right up. After getting everything fine tuned I attempted to connect the tach back up. Not going to happen, each time I connect the wire the engine dies. After researching I thought that the tach being so old that I should replace it. Id did and still nothing and also when I connect the tach wire to the neg side of coil the engine dies. I have read something about a tach amplifier in the manual but for the life of me cannot find any type of replacement or picture of what it looks like. There is a inline connector that just plugs together and then connects to the neg side of coil. Does anyone have any Idea of what this is, Can it be bi-passed, Has anyone ran into this problem before, can I run a direct line from the tach to the coil, and lastly have you ever ran into this problem before and can the tach amplifier be replaced. Thanks for any help you can provide.

 

[TuffleHunden]

Hello: Anybody? Something? Anything?

 

[Bondo]

Hello: Anybody? Something? Anything?

Ayuh,.... No idea what yer talkin' 'bout,.....

In my world a tach is wired to the (-) terminal on the coil, or to the alternator on a diesel,......

It Sounds like the wire from the motor to the dash has a dead short to ground,....
Or, the tach is wired wrong,.....

The single huge paragraph is tough to decipher too,.....

 

[TuffleHunden]

Thanks Bondo, I think you got the idea, when the tach is connected to the neg side the engine, it will not fire, it will only crank. If I disconnect the tach wire from coil it runs perfect. and while engine is running if I touch the tach wire to neg coil it sparks and engine dies. So If it has a dead short to ground can you tell me the best way to track it down? Also Can I bybass and run another wire from tach to neg coil? will it harm anything?