2006 Ford F750 tach wire

Has anybody worked on one of these. The fuel injector only reads .085 volts at idle; hardly usable. I think the smaller trucks use a light green with white but this a totally different animal. It has a caterpillar diesel under the hood and air brakes for goodness sake. Anybody got an idea for finding the tach wire besides randomly stripping every wire at the ECU? It's an automatic and does have a tach on the dash.

Go to these web sights and post the question in the approriate topic area. I think you will get a quicker resonce there, since not too many people are putting alarms on big commercial trucks like this. Normally LoJack. http://www.ford-trucks.com/ http://www.thedieselstop.com/