i have MS1 Pnp. can anyone build me a circuit to control efan thru megasquirt? is it accurate or should i just get something aftermarket?

 

Go to kingefi.com and ask for Matt.he can get you the better prices around plus he does awesome work,tell him that Joey from the rx7forum send you.

 

you should just build it yourself. this is a transistor circuit that will operate an E-fan relay. it seriously is only three components.. a 1k resistor, a 2n2222 transistor, and a IN4002 diode. well plus a 12v relay..i forget which output to use for efan but its not hard to figure out. plus you learn alot doing it yourslef. hell for 5 bucks i might be able to make you one.

 

Yeah, I did that same thing myself and it took me like 2 minutes. n dont forget to use the diod at the relay.

 

I got it working too you can!

 

idk if i can trust myself building one. can anyone do it locally since its my DD cant afford to be on foot for too long.

 

can i just buy this?

 

http://www.sparkandfuel.com/catalog/...products_id=40

 

yes. you can buy that kit.... but you are going to have to solder it yourself. its not very hard.. really. just read up on how to solder.. get a soldering iron. and practice on some spare wire. if you have a PNP then i assume that its a version 3 pcb. there is space on the v3 pcb megasquirt board called the proto area. its a space for you to build extra circuits for stuff like fan control.

 

awsome thanx i will buy then.. ill let u guys know how it goes

 

any have like a picture how to?

 

now after the circuit is biult which wires go where to relay?
only one wire comes out of megasquirt?

 

Matt has done several units for me.. I'm out money for 2 months though.
Check his ebay feedback:
http://myworld.ebay.com/kingefi/

I hope he can correct it..

 

ok here

ok the box in red is on the proto area. if you open your ms case there is an area to build circuits and it has a +5v and a 0v GRND pin hole above it. that is where you pick up the ground for the circuit.

1. put the 1k resistor and the 2n2222 transistor in the proto area and make the connection indicated. you will have to search for the pinouts for your transistor because it is directional. i beleive the MS assembly instructions has a pinout diagram and tells you how to use transitors correctly. there are 3 pins on the transisor one goes to ground, one goes to the 1k resistor, and on goes out of the ms for the signal to turn the relay on.

you can get out of the ms case by going to SPR1 like the diagram shows. its a pinhole beside the db37 connector. you will then probably have to add a wire to your harness to get to the relay.



2. connect the 1k resistor to the output pin on the pcb. if you pull the MS chip there are pinholes that are labled with what output they are. you need X2 (JSO) for fan control. the labels might be on the opposite side of the board so you might have to turn it over to read the lables.

3. now supply the relay with 12volts (fused) from the engine bay area and hook the signal ground from the ms to the relay. you will have to place the IN4002 diode between the 12v source and the signal wire. there is a stripe on the diode and this indicates the direction. the stripe has to be on the side for 12v.

4. wiring the fan to the relay is up to you. if you dont know how to do that then send me a private message or place a picture of your relay and ill tell you how to wire it.


good luck! im pretty sure this is all correct. i was in a hurry so i might have goofed something up so some please confirm this for me. thanks.

 

I've built the e-fan circuit just for testing purposes, the following picture shows what I've done...

Green arrow is signal from megasquirt, black is ground, red arrows go to relay



now, I've tried using three different outputs from megasquirt to no avail. I've tried using FIdle (pin30 on db37), js0 (IAC1a), and js2 (IAC2a). These are the settings I tried in megatune trying to get js0 to work.


(ignore rpm value, was incorrect when I took the pic)

I tested the wires with a multimeter when I was trying to get the outputs to work and I didn't receive any feedback at all with any settings for any port. Also, I'm not sure if my relay circuit is working because when I connect my circuit to +12v the relay activates, is that normal? I thought the signal from the megasquirt would have activated it. Anyway, if anyone has any ideas on what my problem may be I would love to hear what you have to say.

 

if the pinout for that transistor goes E (emitter), B (base), C (collector), from left to right. then the left (E) connects to a ground source in the megasquirt. the middle(B) connects to ouput X2 (JSO) underneith the MS PCB. the right (C) connects to the realay coil and supplies only a ground to the relay.

ok up top the diode has a stripe on it. the wire on the stripe side is 12v from a 12v source and also supplies 12v to the coil. now you have to make sure that your realy is wired properly which it may not be if it operates when you supply 12vs. also you have to set up fan control in megatune.

if you have megatune 2.25

1. click on Basic Settings > Codebase and OUtput Functions.

2. Click X2 (JSO) and set to Fan Control.

3. now click on More Settings > Shift Light/Fan/Output 3+4

4. now set the appropriate temp range for the fan to operate.

 

yeh my bad, I forgot to mention that the top leg of the diode in the pic goes to +12v, doh!

I have MegaTune 2.25 p1 and I dont see any Codebase and Output Functions options listed in basic settings...



this is really hurting my brain...

 

umm yeah mine looks alot different. i dont know much about code variants, but maybe because im running MSNS_EXTRA it might be different. ok youll have to search around in megatune and do 2 things... at least i think..

1: set the output to run a fan

2: set the temp for the fan to turn on.

in the verision that you are running, step 1 might be in the same place as 2.. but i really dont know much about it. check the basic/advanced user tab. and also advanced tab.

 

I'm not even using the circuit anymore, just using the output from FIdle to ground the relay and it seems to work fine! FIdle just appears to be a grounding output rather than giving a voltage output.

 

ok so it doesnt work fine, the ms cant handle the relay and goes crazy!

so I've been going nuts for the past week trying to work out something for my fan control. I've got the circuit working as above but the base of the transistor needs power to switch it, not a ground which is what I need to be happening. I'm really, really, really ready to burn my car to the ground so if anyone has any insight on anything that could help me get this piece of **** working it would be greatly appreciated.

also if anybody knows why NONE of my outputs work except for this stupid switched ground Fidle output, I would love to hear from you.

 

so a pnp transistor got the circuit working with the ground output, but the ms hates that too... I'd say theres something wrong with a component in my megasquirt so I'll have to pull it out of the car and go over it. If anybody has any suggestions as to which components might be responsible then I would love to hear about it.

 

For issues like that, you're better off asking in the official ms forum where there are a no. of people with electronics knowledge to point you in the right direction where to look.

 

good point, cheers.