So as I'm trying to figure out why my aftermarket tach didn't work, I discovered that somebody did this:







The original ignitor (ignition control module) was cut off and this other one was screwed to the side of it, and wires spliced from there.





This apparently was the ignitor that went on some trucks - but not mine.


So I think this explains why the tach wasn't working. The service port I found was probably for something else - the tach service port is part of the igniter wiring harness which is missing.

Also, I sometimes have to jiggle all these wires a little to get the engine to fire up. A new, stock igniter is $300, by the way....

So my questions are:

1. Would I get "better" performance with a stock igniter, or would cleaning up all this wiring produce the same effect?

2. With the way it is currently wired, anybody know which wire I would tap into to connect my tach?

The colors coming out of this ignitor are black, yellow, brown, white, and red.

 

$100 to $140 at RockAuto. It pays to shop around.

If by "better performance" you mean "not having to stand by the side of the road in a snowstorm jiggling some wiring," then I think you probably will. Man, that's really scary looking!

You probably got instructions with your tach. It probably told you something like "hook into the tach connection, but if you don't have one ...." It's likely that it will run from the coil wire. On a stock igniter/coil that's a black/white wire, but it doesn't look like you have anything that didn't come from Dr. Frankenstein.

This may (or may not) help: https://www.yotatech.com/forums/f116...gniter-287857/