jacob80

Ok, so here is what my test has concluded: ON: OFF: Why does my collector voltage go UP when I disable the output? Shouldn't the collector be at 0v/cut off ground to the relay?? Also, why am I only getting 8.2v when the output is on??? UGH, help!

This is something I will keep in mind. Its as if I would tune for a good cruise AFR of ~14.7-15.0 but then when you're coming down from some high RPMs in decel it'll pop like a mother and you're forced to richen it up to get it to go away. Still battling this...

Yeah, thats what I'm thinking. Then again, I may have been poking the wrong pins. I'll let you know how my tests turn out!

I'm beginning to see your viewpoint. Are you saying that the transistor is really just switching on a ground? I know you mentioned this briefly before, but I've always been under the impression that a transistor either switches on or amplifies current. So looking at this diagram: http://i617.photobucket.com/albums/tt260/jacob80a/fancontroltransistorcircuit-2.jpg?t=1280075065 If I put my multimeter leads on Pin 27 and Pin 29 while Output 1 is off in megatune, I shouldn't see voltage, correct? Then, vice versa, if it is on, I should see 12v+, correct? Where I am confused is in my test: Output 1 off: 12.69v DC Output 1 on: 8.09v DC Why am I getting ANY voltage when the circuit is switched off? Perhaps I'm doing something wrong? I'm going to go back and put my leads on the emitter and collectors and do my continuity test. The only thing I am confused about is the voltages in my test. EDIT: I found this on physlink.com: "The collector is the larger electrical supply, and the emitter is the outlet for that supply. By sending varying levels of current from the base, the amount of current flowing through the gate from the collector may be regulated. In this way, a very small amount of current may be used to control a large amount of current, as in an amplifier." Is this a matter of electrical supply, or is this just a matter of completing a circuit, regardless of flow direction?

Holy crap! Stock block?

Looking at these two diagrams: http://www.diyautotune.com/tech_articles/common_megasquirt_modifications.htm#Add_Output_v3 http://msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm#outputs Essentially, the top diagram looks like it is only manipulating power (or ground, not sure whether its grounding or sending 12v+) to the coil positive (or negative). But, the bottom one is showing that it wants to be attached to both sides of the coil, hence my last drawing routing two separate leads out to the relay board. Which one is better?

Your theory is making sense now. I assume that diode is strictly to protect from voltage shooting up the ground? Let's look at this diagram: As of now, I have it wired like so. This diagram is a little more confusing to me because it looks like it wants to feed 12v+ to BOTH side of the relay coil, and my test isn't showing any conclusive evidence that it was working on the bench (I'm looking for 12v when output 1 is on and 0v when off I would assume). I COULD go back to the other way I had it wired, but this diagram was pulled directly off of MSExtra.com and I believe it is a reliable source.

Tested this configuration and here are my findings: Output 1 off: 12.69v DC Output 1 on: 8.09v DC Is this right? In my mind, logically, I would think that when Output 1 is off then it would read 0v DC and when on, it would read 12.69v DC. I'll go out and test this and perhaps invert them so that I get 8.09v DC when off and 12.69v DC when on and see what that does.This is the first time I've ever done anything to the PCB board, so bare with me! Thanks guys!

Okay guys, here is my final rendition of this wiring scheme. I really hope this works this time, otherwise, I have no clue as to what to do. Let me know what you guys think and whether or not this looks right:

Oh for Pete sake, I'm having no success, even with this configuration...DAHHHHHHH!!!! Matt Cramer, please step in

Okay guys, here is the FINAL diagram for the transistor circuit. Each one of the leads that will go to the relay board will be on opposite sides of the relay coil. Check it over if you will, just want to make sure everything is right, thanks guys!!

I will be wiring per this diagram: My question is, will I need to use two outputs, one for ground and one power power, both connecting to thecoil on the relay, correct?

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?

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!

"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

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!

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.

I wouldn't necessarily say don't start with this, but going into it, just know that you have a LOT of work ahead of you. But, I see it more of a challenger/learning experience more than anything! Secondly, I am wondering why you bought a fart can before something significant such as new suspension bushing, or quarters, or something that is going to help you make progress.

As far as sourcing a motor, I've had luck using online "junkyard" sites per say. All theses websites consist of is an inventory database and it will usually give a very brief description of the motor by using abbreviations (Ex: OP 45 = Oil pressure tested 45 psi). I will admit, an L28ET isn't going to be an easy one, but they're out there. The first one webought was out of Georgia for ~$500 shipped to our door and the second one was in a town ~60 miles away (this was sheer luck!). Luckily, both of these motors have shown up in pretty good condition. Good luck! Inventory site: http://car-part.com/

I have the R/T mount and I STILL get the clunk. I'm using the energy suspension bushing, I would assume its poly (red). I have also replaced ALL bushings all around. perhaps I need to take your advice with this washers thing. I may need to draw up a digram to interpret what you mean, but perhaps that is my problem. The bummer about this whole thing is that I had the EXACT same sound as I did before installing the R/T mount. I've put a new rear end in, all new energy suspension bushing, 280z 27 spline stub axles and 300zx turbo CV shafts, and the R/t differential mount. Grr...

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!

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?

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

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.

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