Still nothing.

 

Pin 28 is power from the harness. That's a problem

 

I have power from the harness though. I check with it unplugged key on and had 12v. Red/White wire factory harness.

 

OK so how about between pin 28 and pin 8. Make sure you are checking the correct pin. This is on the blue main board.

 

We talking about the 40 pin connector we have been testing up to this point right?

 

No sorry. This is the db37 connector on the blue main board. The one the harness plugs into.

 

Diagram of which pin is which?

 

http://msextra.com/doc/ms3/General_Pix/v3-wiring.png

 

Took the bottom off and counted the pins over, still nothing.

 

Connector not making contact I'm guessing?

 

Set your multimeter to ohms and check the connection from the harness pin for power and the pin on the db37 connector

 

It shows continuity.

 

Messing around with the multimeter, probing the power pin on the db37 connector. Other end poking around, I'm finding a lot of them show 60.7 on the 200k setting. The middle foot shows 60.7 on u5 and the right foot shows 61.5.

Port 32 shows 60.7 and port 31 shows 61.5
Port 1 shows 61.5 and port 2 shows 60.7
Port 19 shows 60.7 and port 20 shows 61.5

This is all from the power pin.

A ground pin shows continuity to everything I just said.

 

Probing the connector end again on the db37. Power pin on one, every single one besides 3, 4, 5, 6 on the top row show 60.9.

20 and 21 show 64.1.
24 shows 62.6
26 shows 61.7
All else show open.

 

**** man I'm stumped. The way to figure out what is wrong is to trace to where the voltage stops. So we would start at the harness connector and find 12 volts then check each connection after that until we don't find 12 volts. The 3 easy connections are. At the harness connector, then at pin 28, then at u5 on the right pin. So if we have 12 volts at the harness. Then not 12 volts at the db37 connector the problem has to be between the harness connector and the db37. If you had access to a power supply we could try connecting it directly to the MS3, I'm pretty sure you can use a 9v battery to do the tests in step 24 from the build manual above. I would try connecting a 9v battery to power and ground on the harness connector and tell me if you what voltages you get at pin 28. Right and left legs of u5. and the pins on the 40 pin cpu connector. All these should be tested against ground. either pin 2, 8, or the ground in the proto area.

 

Those readings were on the 200k OHM setting. Was just messing around checking resistances and such. But if my power pin on the db37 connector shows a resistance of 61.5 on the right leg of the u5 then something isn't right since it needs 12v?

 

Missed that. So the right leg of u5 has continuity with the middle pin? If so you have a short. At this point I would pm Braineack and email DIYAutoTune. They will be able to help you diagnose what is blown/shorted. Update this thread if you figure it out. I'm interested. I don't know the board well enough to diagnose more over the internet and mine is put away in my car. But those guys should be able to help.

 

Yeah, the right leg of u5 shows continuity to the power pin 28. So does the middle leg. So does those 3 sets of 0v and 5v pins on the 40pin cpu connector. But it doesn't show a clear path, IE 0.00. It reads 60.7 and 61.5.

 

What is the resistance between the right and middle leg of u5

 

Just sucks I got it this way. I'm sure it can be fixed but I wanted to have the car running by now...