fifty New Reader
7/23/09 6:36 p.m.

I've got the sensor and power grounds run as 2 separate wires in my MS install - does it matter if I ground them both to the (-) battery post, or should I ground them to 2 separate locations?

Thanks! Iain

Xceler8x Dork
7/24/09 8:20 a.m.

My MSPnP documentation suggested using different grounds. They suggested using the motor to ground the cpu while using another location to ground the wideband. Now that I reread your question I'm not sure if that's what you're asking. I get the power ground. That's for powering the unit. But by sensor are you asking about a wideband or another sensor?

pres589 New Reader
7/24/09 8:43 a.m.

I would use separate ground locations, you may have high frequency ripple out of the ECU or a sensor or both; getting a little distance between them can help reduce problems with that sort of thing.

It's what I was always told to do with aircraft system installations in my former life as an aircraft electrical engineer and I can see how it might work out that way. Short ground wires to good grounding locations, and make sure the engine block itself is well grounded, and you should have a good shot at a trouble free install in this regard.

MadScientistMatt Dork
7/24/09 9:09 a.m.

The absolute best configuration is to run all the sensor grounds to the MS with one wire, then ground all the other MegaSquirt ground wires to a single point at the battery or engine block.