07-21-2013, 01:56 PM
Join Date: Mar 2008
Total Cats: 0
MS wiring questions - fan control and CEL
I have a '90 with Greddy Turbo, with a DIYautotune MS-1 Extra. I bought the MS used, didn't build it myself.
The car is currently running. MS install details:
- PCB v3.0
- piggyback to an oem ecu
- LC-1 wideband, wired to oem ecu input
- MAF delete
- GM IAT sensor is wired direct to MS
1. I did a coolant reroute with water neck delete, and I cannot get the MS to activate the fans. I've double-checked the settings for the temp activated JS3 output, which are correct insofar as they match what people have posted on the forum. The fans do work if I ground the thermoswitch lead or the appropriate diagnostic terminal, so I know the fans work and relay is fine. I've also tried turning on every other MS output, in case mine is wired differently, but no luck there.
So, today when I get to the shop, I'll open up the MS to see if it needs a modification for the fan output. Question is - what should I be looking for? As I understand, I should see a different FET wired in place of the middle LED transistor and then a jumper from that LED to somewhere else? Can someone clarify and/or send a picture?
2. I want my CEL to work as much as possible, or to at least look like it works properly (e.g. turn on for a few seconds at startup). Am I right in thinking that I could accomplish this with the following two changes-
A. Wire the LC-1 direct to the MS (pinout 23 on the 47 pin connector) and then rewire my narrowband o2 back to where it belongs on the oem ecu.
B. tap into the IAT signal wire and connect it into the oem ecu (which pinout should that be?) so that the computer 'sees' an appropriate resistor range and thinks I still have an AFM.