Megasquirt repair

[STOICH]

Long time no see! I have been enjoying my MegaSquirt now since about 2012, however have now encountered an issue and have some crispies on the main board. Push come to shove, I may try to fix it myself, but at this point, I'd rather send it in for repair. I can't find any contact info on what appears to be the main homepage of Megasquirt so.... how does one get in contact with them nowadays? Thanks for the help!

[Piledriver]

Mario at http://thedubshop.net is an option as is http://diyautotune.com

[ps2375]

Do you know what caused the crispies?

[STOICH]

Fantastic I could not for the life of me remember the DIYautotune website name. Was drawing a blank on where I got it. Thanks for the help!

As for cause, I'm suspicious of a ground in the wire harness but am not certain if that ground was actually coming from the ECU itself, or if the harness is to blame. Guess that is a project for after the holidays. Thanks for the help!

[ps2375]

The MS unit is a "ground switching" device. Meaning that it controls loads by switching on/off the ground for said load. So a short on the harness would bypass the MS unit's control of the load, sounds more like you have too much of a load on that control circuit, it is meant to control relays and low current things like that or it may need modded with high current transistor(s) to handle the load you have on it.

[Clonebug]

Fantastic I could not for the life of me remember the DIYautotune website name. Was drawing a blank on where I got it. Thanks for the help!

As for cause, I'm suspicious of a ground in the wire harness but am not certain if that ground was actually coming from the ECU itself, or if the harness is to blame. Guess that is a project for after the holidays. Thanks for the help!

I recommend Mario at www.thedubshop.net if you need repair.

He is quite reasonable and can fix it quick if he is not inundated with orders.

He is also not too far from you.......

[STOICH]

So it is C16 that smoked... I ordered the capacitors as described as I supposed maybe Mario is on vacation or something. (I Haven't heard back but I got to GO!) I have used this config since 2012 so I can't guess the malfunction is something from the OE build unless something chaffed due to vibration. I did find a LED out of place a tad, but not really to ground. (In the spirit of Megasquirt I drive the SHI*t out out of this thing so) Anybody wiling to save me some book time on the purpose of said C16? All thoughts are appreciated. I'm still willing to send the ECU to Mario or DIY or fix it myself if need be, but I'm convinced it is a chassis borne electrical problem that caused it.

[ps2375]

C16 is part of the board's power supply section. If you replace it yourself, be sure to install it correctly, as it has a polarity and is marked. (I am assuming you have a v3.0 board.)

[Piledriver]

Replace C16 and go.

C16 is sort of infamous for blowing up--- it really needs to be a 35v part, rather than a 25.
Newer boards have a higher rated part.

See http://www.msextra.com/forums/viewtopic ... 01&t=59067

[ps2375]

Really gotta love the online support for MS.

[Piledriver]

If you are ordering the cap. pick up one or more 22v MOVs.
These are the same type of active device a surge suppressor has.
https://www.digikey.com/product-detail/ ... ND/2799109

They are cheap insurance, and can go on the terminal strip or relay feeding your MS.

Put them after a fuse.

[STOICH]

Thats good to know, and thanks for the tip. Maybe next time I'll smack the fuel pump one less time before looking to C16

[STOICH]

So I stuck a new capacitor in the board and went to plug it in to find that I had fuses blowing at every attempt. In short, I now know that I had some sort of major catastrophic wire harness problem (entire car, not just ecu) that I am now attacking. When I wired it the first time, I recall reading that the insulated wire for the distributor could not be shortened to due resistance values. My entire harness is believed to be shot so I'm about ready to cut it in half for removal. I do intend to rebuild the harness, however that one wire is stopping me from digging in. Am I recalling correctly that this wire cannot be manipulated or is my memory shorted also?

[ps2375]

I don't recall anything like that. They make long and short harnesses that will work on these with no additional modifications. That sounds like you are thinking of a Ballast wire for a coil on a points triggered setup.

[Piledriver]

STOP.

The cap blowing may have done other damage, did you try the ECU on a stim first?

Before assuming the wiring harness has bad karma, troubleshoot something.
There are very few harness problems that can cause damage.
12v shorted to 5v is one of them, shorted to gnd or power sensor lines are largely the other scenario.

Its far more likely capacitor guts shorting something out in the ECU--tantalum caps go off like firecrackers, and almost all the bits are conductive metal fragments, explosion was contained in the ECU case, so was all the trash.