I did a conversion with my G30 to a G20 with my WM Pro -1200. I get about 10 jobs and the coil keeps frying. The RPM's of the truck are set at 1400 when running. I'm wondering if the coils are just getting to hot under the doghouse and causing premature failure. Can I go to a better coil or won't make a difference.
That is far too often for a coil to be going bad like that. Even a cheap coil should give you more life than that. Each time the coil went bad did you test it? I suspect you could have an underlaying problem. Maybe a short somewhere or possibly a bad relay that will not close. If it were my truck I would look into both of those possibilities. Next time it happens try tapping on the relays with the handle of a screwdriver and the key in the on possition. If you have a stuck relay you will hear it click when you tap on it if its bad. I have no idea what kind of truck this is or a wiring diagram for that matter. So i cant tell you exactly which relay it could be
I did a little peeking around and noticed the negative wire coming from the coil going back to the tach on the unit is mounted in the center post position. I also noticed a little dial on the tach that has a position 4, 6, and 8. Mine is set to the 6. I think this may be cylinder of vehicle but not sure. Any older WM Pro-1200 owners please chime in and take a peek at your unit and let me know what positions your wires are in. Chevy G20 1995.
Yeah, this is a tough one to diagnose. This is a Chevy 1995 G20 with a WM Pro-1200. I do have a wiring diagram but it is for newer Pro-1200 and not much help. I did email Jon Duda at WM who has assisted me in the past. I'm thinking a wire in the wrong place or a stuck relay like you had mentioned.
Oh, I did bypass the waste float shutoff a while back. I wonder if thismay have something to do with this issue.
