My box had one plug on top. It also had a small plug looking thing that came separate. I did not see where to hook it up or a place to plug it in. I suppose that may be the temp sensor. I did not hook anything up other than the main plug. Mine works great.
ahhh, I think I figured it out. This link tells me that the extra plug is for the data logging hookup.... I thought it required another cable type to go to the sensor that came with it.
I will install the new sensor, hook it back up and try it in the morning.
I'll give you a call on your cell to tell you how I make out.
G503.com Message Forums • View topic - brand new PCB box out
SUBJECT: HMMWV Smart Start System (S3) control box, NSN 6110-01-542-7901
ISSUE: Need your help getting the word out. The new S3 control box has made its way to the field. The S3 control box is replacing the engine electrical start system (EESS) control box.
The S3 was cut into HMMWV production starting with serial number 255269. Ordering this NSN will get you the S3 box along with the temperature sensor.
The most noticeable difference is the S3 control box has three connector receptacles, unlike the EESS control box that only has two connector receptacles. The third connector receptacles on the S3 control box will be used at a later time for data logging and troubleshooting.
The EESS controller and the new S3 controller are interchangeable.
Currently the TM 9-2320-387-24P does not reference the S3 control box. This change will be incorporated in future TM updates.