No spark MS1 V3 Hall setup

pdooley · Post by **pdooley** » Sun May 07, 2006 3:21 pm

I have MS1 V3, MSnSe 024s, hall setup running on-board VB921 chip.

I got this mod from other people that have succesfully inplemented it:
5volt input to hall sender by running 5v from proto area to tachselect/optoin jumper.
Jumpered XG1 to IAC-1A. IAC-1A goes to pin25, which is hall sender input signal wire.
5v power to the hall sender comes from pin15.

Car won't start and pulling coil wire shows one spark shortly after ignition switch is turned on, nothing while cranking.
I probed hall sender wires and found 5v on the signal wire and nothing on the power wire. I checked the wiring harness at least 5 times and can't find anything wrong. Very confused now

pdooley · Post by **pdooley** » Fri May 12, 2006 9:02 am

OK, after much

I determined power to the hall comes in on pin24 with the given mods.
I was getting info from somebody using a relay board, which translates to pin15.
All is well now

Post by **jsmcortina** » Fri May 12, 2006 9:26 am

Do not connect this Megaquirt to a Stim or you will damage the stim because you are supplying 5v to pin 24 which is designed as an input.

James

pdooley · Post by **pdooley** » Fri May 12, 2006 6:11 pm

whoops- already did..
It didn't work so I figured XG1-XG2 should be jumpered for good measure.

It still didn't work so I gave up.
After all that is when I figured to power the hall with pin24 and the car ran for the first time today, so the MS is not damaged.

Hmmm, what components are likely to be damaged on the stim?

Post by **jsmcortina** » Sat May 13, 2006 4:00 am

If pin24 (tach IN) on your Megasquirt is connected to 5v then the transistor on the Stim will short it to ground and most likely damage itself.

James