jacob80 Posted July 19, 2010 Author Share Posted July 19, 2010 I'm totally unfamiliar with the terms "SPR1" and "S terminal," I will research. In the mean time, feel free to fill me in Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 19, 2010 Author Share Posted July 19, 2010 Here's a more distinguishable diagram I found on the MS site: Is this what it will look like? Will this all be right inside the ECU box? If so, where do I run wires OUT? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted July 20, 2010 Share Posted July 20, 2010 I'm totally unfamiliar with the terms "SPR1" and "S terminal," I will research. In the mean time, feel free to fill me in SPR1 = a pad on the main board that connects to DB37 pin 3. Standard relay cables don't use pin 3. S terminals - S1 through S5 on the relay board. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 20, 2010 Author Share Posted July 20, 2010 (edited) SPR1 = a pad on the main board that connects to DB37 pin 3. Standard relay cables don't use pin 3. S terminals - S1 through S5 on the relay board. So I would have to take apart the cable that goes from the relay board to the ECU and add a lead from SPR1 on the PCB to an "S" terminal on the relay board, correct? I will read up a bit more on the wiring side, but I will say I am still unclear as to how the "JS..." part of it ties in. Thank you for your help Matt! EDIT: Just did a little reading and came across this diagram that shows the relationship between the DB37 and relay board: http://www.bgsoflex.com/mspower/mspower_ShemV1.2.pdf Looks like Pin 3 on the DB37 is a ground, which would make SPR1 a ground, correct? Then, it looks like S1, S2, S3, S4 and S5 are screw terminals 7, 8, 9, 10 and 11 on the relay board respectively. I'm sure the "S" terminals are labeled on the PCB, correct? Also, what would I need to ground using SPR1? I already have ground my relay to a common ground source. Thanks!! Edited July 20, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted July 22, 2010 Share Posted July 22, 2010 Don't wire it to SPR1 - use one of the jumper pads meant for the MS2 IAC wires. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 23, 2010 Author Share Posted July 23, 2010 Don't wire it to SPR1 - use one of the jumper pads meant for the MS2 IAC wires. Wire it like so? Per this guide? (scroll down to "Adding an relay control circuit to the MegaSquirt PCB-3") http://www.diyautotune.com/tech_articles/common_megasquirt_modifications.htm Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 23, 2010 Author Share Posted July 23, 2010 Looking at this diagram: If I instead jumper to "IAC1A" opposed to "SPR1", will this come out as "S1" on the screw terminals on the relay board? I have the relay cable from DIYAutoTune which says it is wired with all the MS2 IAC wires. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 23, 2010 Author Share Posted July 23, 2010 Also, using JS3 as a processor port, I don't see an option to set it as Fan Control within megatune, only JS0...? I think I'm just going to wire to JS0 Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 23, 2010 Author Share Posted July 23, 2010 Okay, I think I got it! I tested it by putting on my stim and plugging it into my Mac. I set it so the fan would come on at 200 degrees. I put one lead of my multimeter on the negative power supply post and the other lead on the IAC1A jumper (which eventually turns into DB37 Pin #25). Everytime I would adjust the stim equal to or above 200 degrees, the multimeter would beep in continuity mode. I was getting little to no DC voltage when I tested it on the multimeter. Can I safely say I was successful? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted July 23, 2010 Share Posted July 23, 2010 That diagram is somewhat generic. SPR1 does not go anywhere on the relay cable. You don't have to, and in many cases should not, use the same input and output sources. It's just one example! Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 23, 2010 Author Share Posted July 23, 2010 (edited) That diagram is somewhat generic. SPR1 does not go anywhere on the relay cable. You don't have to, and in many cases should not, use the same input and output sources. It's just one example! Yes, I finally started understanding the whole thing! IIRC, SPR1 pins out to Pin #3 on the DB37 (which you said a standard relay cable will not be equipped with) and I've already gone through the hassle of taking of the hood of the cable, passing it through the firewall and reassembling it, so I really didn't want to hassle with that if I could just use another output from the ECU. I did some research and according to DIYAutoTune.com, the Relay cable they sell is wired for all the MS2 IAC pins to the relay board, so I went ahead and used IAC1A (which is S1 IIRC on the relay relay board screw terminals) and, like I said, my multimeter continuity test would resound everytime I would set the stim CLT above 200 degrees (which I assigned in megatune). Could I safely say I was successful here, or is there another test I could conduct to confirm this? Thanks Matt! Edited July 23, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 24, 2010 Author Share Posted July 24, 2010 (edited) Ok, here we go: Tonight, I finally got a majority of all the EFI wiring put together and had the chance to test my new little transistor circuit. Here is how I wired it: Seems as though I was unsuccessful. I went ahead and pulled the lead off of the relay board terminal S1 (which IAC1A is supposed to pin out to Pin #25 and then to S1 on the relay board) and touched it to one of the injector power terminals and the fan kicked on, so I know the relay wiring is right, just looks like I'm not getting this output to work. In the following video, I'm basically trying to show that I am getting continuity between the two leads when the output kicks on, but no continuity when it kicks off, yet the S1 terminal on the relay will not kick the relay on/off. Video: I am only getting .005 volts when Output 2 is On! Also, I am getting 14.1 volts to the banded side of the diode but only .005 to the non-banded side (which is the side that should be providing power to my transistor). I just talked with digikey and she said that the diode is actually wired backwards and that I should switch it, so I will be doing just that. In that case, my diagram is drawn incorrectly. Edited July 24, 2010 by jacob80 Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 24, 2010 Author Share Posted July 24, 2010 So I switched the resistor around and now I'm getting 12v to pin 25 regardless of output 2 being on/off. UGH. Matt, I could really use your help right about now! Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 24, 2010 Share Posted July 24, 2010 (edited) I'm not exactly in the loop on this subject. Isn't pin 25 supposed to be a switched ground? Shouldn't Pin 25 read zero volts and have continuity when on. From what I'm gathering it feeds the ground on the relay coil. Your tests were showing it switching on and off and it was reading almost zero volts. So if you have 12v fed to the other side of the relay it would switch on, correct? If i was to run this on my car without a relay board, pin 25 would be hooked to the relays coil negative and the other side switched 12v source. If I'm understanding the operation correctly. Correct me if I'm wrong, because after you get it working I may do the same thing. Edited July 24, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 24, 2010 Author Share Posted July 24, 2010 "The following IAC outputs are capable of driving over 0.5 Amp directly, sufficient for most automotive relays. You can connect to them using the IAC pins on the DB37 (25, 27, 29, and 31). Also, note that IAC1A and IAC1B are inverted relative to each other, as are IAC2A and IAC2B." I have wired to IAC1A and want to use pin #25 on the coil positive. Unfortunately, now that I switched the diode, I'm getting a constant 12v regardless of whether output 2 is on or off...grrrrrrr Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 24, 2010 Share Posted July 24, 2010 (edited) That's what I'm thinking maybe off, I don't think your trying to feed 12v to the relay. The 12v source is switched or constant. Pin25 should be grounding the relay to activate it, it seemed to be doing so in your test. Again I maybe totally off base. If you did hook pin 25 during that test to the negative on a relay and a 12v source to the positive, it would of been turning on and off. Edited July 24, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 24, 2010 Author Share Posted July 24, 2010 My first test with the banded side of the diode to the 12v source shower .005 volts regardless of putput 2 being on or off. I installed this setup on my car and the fan did not work. I isolated the problem to a megasquirt issue by testing that my fan worked on a known, reliable source, and it did. Now, I've switched my diode around so the banded side is to the transistor and I am now getting 12v to IAC1A regardless of whether or not Output 2 is on or off. It seems as though the transistor isn't doing its job for some reason. Regardless, I'll always question my wiring, but before I tear it apart for a THIRD time, I'd like to see if maybe this 12v condition is normal or there is some setting within megatune that I'm missing. Thanks! Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 24, 2010 Share Posted July 24, 2010 (edited) This is the diagram that gets me. C to terminal 85 on the relay which is ground, 86 being your switched. Comparing with the other diagrams IAC1A shouldn't be seeing 12v. I'm thinking that the .005 volts was what you wanted to see , as long as it was completing the circuit when it was suppose to. I do think it was working like it was supposed to. Edited July 24, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
jacob80 Posted July 24, 2010 Author Share Posted July 24, 2010 Hmm...interesting. If this is true, then my relay is wired wrong. I have it wired so that the Megasquirt would be providing 12v. Should I rewire the relay AND turn the diode back around? Quote Link to comment Share on other sites More sharing options...
goodoldjam Posted July 24, 2010 Share Posted July 24, 2010 (edited) Hmm...interesting. If this is true, then my relay is wired wrong. I have it wired so that the Megasquirt would be providing 12v. Should I rewire the relay AND turn the diode back around? I'm thinking you probably should. You can test it by hooking up pin 25 to 85 terminal on a removed relay and feeding power to 86. Then when it switches check continuity between 30 and 87, if that is working properly then your ready to go. Which from your testing should work, that was before you reversed it. You maybe could test the connectors on the relay board, you need a negative and a positive on 85 and 86, if you have 2 12v sources that would explain it. Edited July 24, 2010 by goodoldjam Quote Link to comment Share on other sites More sharing options...
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