Articles - Maintenance en-us http://www.cumminsforum.com/articles N/A http://www.cumminsforum.com/articles andy@cougargulch.com 20 http://www.cumminsforum.com/articles/articles/54/1/What-to-do-if-you-Vacuum-Pump-Springs-a-Leak/Page1.html Take a close look at where the oil's coming out. if it's at the red arrow, all your going to need is a new o-ring . Found this out last night. i was losing 3-4 qts of oil in 2hrs drive time. andy@cougergulch.com (Swank Metal) Tue, 03 Apr 2007 00:00:00 -0400 http://www.cumminsforum.com/articles/articles/47/1/Tach-Plug-92--93-trucks/Page1.html Hope this is of some help for folks trying to find the stock tach plug. May also apply to 91.5 and newer as well as the 92 and 93's.The plug is a small flat plug and is located close to the steering column under the dash. The repair manual calls out "Near the fuse block". I think the plug is grey but can't remember for sure. There are 4 wires going to it - Black -Ground orange - Switched 12V red - switched 12v to signal flasher(don't ask cause I don't know!! ) Gray - tach signal from the PCM The crankshaft position sensor is where the signal originates and then goes to the PCM and on to the plug. You should be able to check for a reading at the gray wire with a digital meter. My PCM was bad and it took me a year to figure out what was going on. A new PCM solved the problem. paccoolst@aol.com (Stan Pacool) Tue, 03 Apr 2007 00:00:00 -0400