Electrical gurus please help.

How did the computer die? Will it still spit out codes?
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

Here's a link to get the diagrams you'll need...
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

Start by ohming out the ACT & ECT wiring with the computer and sensors disconnected. You should see 10 meghoms or more.

Check pin 26 (VREF) on the computer wiring harness with the computer disconnected. VREF is supplied to the EGR, MAP and TPS sensors. If you get less than 12 ohms with all of them connected, disconnect them one at a time and watch the change. The one that causes the resistance to increase beyond 10 ohms when it is disconnected is suspect.

stanley514 said:

Ok per jrichker. Less than 12ohms with EGR, MAP and TPS connected or disconnected.

My Diagnostic schematic says I have service short to ground replace ECM? I've already done this and blown a 2nd ECM??

Click to expand...

Following the ECC diagram, 88-91 eec pinout.jif, with the computer disconnected and the sensors disconnected, pins 26(VREF), 47 (TPS), 27 (EGR), and 45 (MAP) should be an open circut and measure greater than 10 Megohms. Pin 46 (Sig Return) is a ground, but with the computer disconnected, should also be an open circuit.