Trigger wheel/EDIS wiring to relay board MS3X

craigibc · Post by **craigibc** » Wed Jan 21, 2015 6:07 pm

I am putting this system back together after I tore it down to rewire the car. I cannot find where the EDIS ties into the relay board. From what it looks like (looking at the wires) the EDIS wiring should go to the relay board and I am lost to where it might connect. I am looking at this document below and now I am more lost than before.

When I check the wiring on the car these wires go from the cam sensor to the EDIS and the EDIS to inside the car.

Where do those two wires go?

Craig

http://www.msextra.com/doc/ms3/edis.html

Post by **jsmcortina** » Thu Jan 22, 2015 4:24 am

That manual page is obsolete, but in any case, the MS3 manuals are drawn up without the relay board. I personally don't recommend it due to the screw terminals which can corrode.

James

DaveEFI · Post by **DaveEFI** » Thu Jan 22, 2015 7:00 am

craigibc wrote:I am putting this system back together after I tore it down to rewire the car. I cannot find where the EDIS ties into the relay board. From what it looks like (looking at the wires) the EDIS wiring should go to the relay board and I am lost to where it might connect. I am looking at this document below and now I am more lost than before.

When I check the wiring on the car these wires go from the cam sensor to the EDIS and the EDIS to inside the car.

Where do those two wires go?

Craig

http://www.msextra.com/doc/ms3/edis.html

I'd ignore the relay board, and wire both SAW and PIP direct to the MS DB37 connector, using screened cable.

craigibc · Post by **craigibc** » Thu Jan 22, 2015 10:09 am

The link to supersede only provides the manual link and not finding the information I need. I have attached a screenshot from the original link and it shows PIP and SAW wired to the DB37. Does this look correct?

I can wire to the upper connection but the relay board is currently using the lower connector. The lower connector would need to work off the relay board.

Insight?

Craig

craigibc · Post by **craigibc** » Fri Jan 23, 2015 9:44 am

I checked my current setup and pin 24 it is recommending for tach input for the EDIS is in use by cam sensor. Is there another pin I can use as an alternative?

craigibc · Post by **craigibc** » Fri Jan 23, 2015 9:48 am

This is what I found on page 74 of the current rev of the manual. From my initial evaluation on the first post it is the trigger wheel wire not the cam sensor I need to wire into the Megasquirt.

Post by **jsmcortina** » Fri Jan 23, 2015 10:13 am

"PIP" from the EDIS module connects to the main tach input.
The cam sensor signal connects to the cam sensor input.

James

craigibc · Post by **craigibc** » Sat Jan 24, 2015 8:02 pm

What does SAW plug into?

Craig

craigibc · Post by **craigibc** » Sat Jan 24, 2015 9:05 pm

I have been searching the megamanual and online forums as well and now I think I found something else. Can I just bypass the relay board and go from

DB37 pin #36 to the SAW pin (#3) on the EDIS
DB37 pin #24 to the PIP pin (#1) EDIS

Can I do this and avoid the confusion I am having with the relay board?

Craig

Post by **jsmcortina** » Sun Jan 25, 2015 6:36 am

The SAW wiring IS covered in the correct manual. Don't ever use the obsolete "Megamanual" with MS3 as it gives incorrect information.

http://www.msextra.com/doc/pdf/html/MS3 ... 3-113.html

James

craigibc · Post by **craigibc** » Sun Jan 25, 2015 12:05 pm

Unfortunately that document provides additional information and not answers.

SAW to SPARK A
PIP to TACH INPUT

When I look at the relay board I see a TACH OUTPUT but not a TACH INPUT option. Also I see no option for SPARK A on the relay board.

Seems like the manual is pointing me west but there a 6 different roads heading west and not sure which one to take.

Post by **jsmcortina** » Sun Jan 25, 2015 12:13 pm

SPK A is shown in the wiring diagram of the manual.
http://www.msextra.com/doc/pdf/html/MS3 ... .3-19.html

There's no tach output on the Relay Board - it is the Tach Input.

James

DaveEFI · Post by **DaveEFI** » Sun Jan 25, 2015 12:19 pm

Lots of things the relay board doesn't cater for. You need to refer to the schematic for it and work out what does what by reference to the DB37 pin numbers and the MS external wiring diagram.

Post by **jsmcortina** » Sun Jan 25, 2015 12:30 pm

DaveEFI wrote:Lots of things the relay board doesn't cater for. You need to refer to the schematic for it and work out what does what by reference to the DB37 pin numbers and the MS external wiring diagram.

Seems it is causing a lot of confusion here. A short section on it in the Hardware manuals would likely help. I'll look at adding that.

James

craigibc · Post by **craigibc** » Sun Jan 25, 2015 11:16 pm

If you could search on the PDF or the online hardware manual it would make it much easier to key in on the right information.

Craig

Post by **jsmcortina** » Mon Jan 26, 2015 4:59 am

Does your PDF viewing programme not allow searching? When I click CTRL-F in mine I can search very easily.

James

DaveEFI · Post by **DaveEFI** » Mon Jan 26, 2015 6:21 am

craigibc wrote:If you could search on the PDF or the online hardware manual it would make it much easier to key in on the right information.

Craig

Think a bit of history (as I see it) might help. The relay board was designed a long time ago when batch fuel only was the norm. Hence no mention of ignition outputs on its PCB legend, and only one tach input.
The norm (to me) with a V3 PCB and EDIS is to use the tach input (DB37 pin 24, marked 15 Tach/ign on the relay board) for PIP, and the ignition output (Pin36 DB37 marked 11 S3 on relay board) for SAW. With the appropriate links on the V3 PCB.

Because MS is so flexible, it would be impossible to print all the options on the relay board PCB.

It really is well worth while to draw out your own individual wiring diagram including the colours of the wires as used. Generic ones are fine as a start - but are never going to be identical in every way to what you end up with.

Post by **jsmcortina** » Mon Jan 26, 2015 7:19 am

DaveEFI wrote: the ignition output (Pin36 DB37 marked 11 S3 on relay board) for SAW. With the appropriate links on the V3 PCB.

Yes, but remember that it is not the standard ignition output on MS3X - "Spk A" is the standard ignition output that is used for SAW.

James

DaveEFI · Post by **DaveEFI** » Mon Jan 26, 2015 9:27 am

jsmcortina wrote:
DaveEFI wrote: the ignition output (Pin36 DB37 marked 11 S3 on relay board) for SAW. With the appropriate links on the V3 PCB.
Yes, but remember that it is not the standard ignition output on MS3X - "Spk A" is the standard ignition output that is used for SAW.

James

Right - even more reason why it would be impossible to make the legend on the relay board correct.

dragbug · Post by **dragbug** » Mon Jan 26, 2015 3:48 pm

jsmcortina wrote:
DaveEFI wrote:Lots of things the relay board doesn't cater for. You need to refer to the schematic for it and work out what does what by reference to the DB37 pin numbers and the MS external wiring diagram.
Seems it is causing a lot of confusion here. A short section on it in the Hardware manuals would likely help. I'll look at adding that.

James

I suggested that back in November in the MS3 New Documentation Discussion and was ignored. Glad to see you have had a change of heart. I know it isn't something you recommend but that doesn't mean it isn't being used for simplicity sake. It can/does cause additional confusion when you want to run an MS3x card though.

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