[dabigboy]

Well I've more or less given up on the fuel pump thing for now.....I'll keep the hot-switch til I have time to majorly sort the wiring in this car (thinking of adding another relay which would be kinda hokey but would make the pump come on/off when it's supposed to, without the hot-switch).

Anyway, I had the ignition coil disconnected the other day to clean connections. After hooking everything back up (I thought I had it the same) the car ran fine but I had no tach. I had a white wire and a green & black one connected to the negative terminal, everything else to positive. Today I got the tach working by connecting the small white wire to the positive terminal.....! From what I've been reading, and going by the schematic, the tach is supposed to get its signal from the negative terminal, and the other lead for the tach goes to ground. I thought perhaps a previous owner had dorked with the wiring and messed this up, but the terminal on the end of the white wire isn't even big enough to go over the positive post on the coil! So it had to be on the negative post originally, which is how I remember it.

Any ideas what could be going on here?

 

[Tifosi]

Green w/black trace goes to + on the coil.

The tach wire will come off the - post as it reads the pulses produced as the ignition fires.

 

[dabigboy]

Ya I tried hooking the green/black wire to positive and the car wouldn't run, no spark........

 

[Tifosi]

Well that makes no sense. Green with black trace are key controlled + leads.

There should be a couple white wires on the coil BTW.

One is the tach signal wire (IIRC) and the other heavier one is for the ICU.

 

[dabigboy]

Ya I got two whites on the positive lead...is one supposed to be white/black? As I recall the heavier one is white/black.

I'm wondering if it's possible to reverse certain wires in such a way that the ignition coil functions "backwards" (in terms of the polarity of the posts) but still does its job. I need to determine the ground wire going to the coil. FWIW the ONLY wire I have on the negative terminal right now is a relatively small white one. I seem to recall at least 2 wires being on there.

 

[Tifosi]

Advance search keyword 'coil' by poster ghnl.

He posted a couple photos a while back with the wires on the coil for reference that might be of use.

The white's I was referring to are solid white, no trace of any color.

Reverse wiring a coil shouldn't work as there is directional resisitance involved.