Raytheon Technical Services Company

Craig Harper

Technical Manager

229-639-8277

HMMWV GLOW PLUGS AND CONTROLLERS:

The spares procurement for EESS has led to another change which will be commonly referred to as the One Piece Design. Because of the differentconfigurations, we have established a generic NSN for EESS procurementpurposes. The NSN is 6110-01-491-2158.

There will be three NSNs related to this generic NSN. They are as follows:

A. 6110-01-463-9260 - 2 piece design manufactured by KDS. This configurationcontains a black control box with yellow label and a temperature sensor witha yellow band. The temp sensor gets installed in the water crossover pipe.

B. 6110-01-491-2142 - 1 piece design manufactured by KDS. This configuration

contains a black control box with a bright green label. There is no longer aseparate temperature sensor required with this configuration. It will notmake a difference whether the glow plug controller (2920-01-175-7214) or thetemp sensor (2920-01-469-6903) is installed in the water cross over pipe.The pin to this lead is dead.

C. 6110-01-491-2152 - 1 piece design manufactured by Signal and Systems,

Inc. (SSI). This configuration contains a black control box and there is noseparate controller or temp sensor. It will not make a difference whetherthe glow plug controller (2920-01-175-7214) or the temp sensor(2920-01-469-6903) is installed in the water cross over pipe. The pin tothis lead is dead.

Any of the above NSNs can be ordered, you will get which ever is in stock.

There are NO Safety Issues related to these boxes/NSNs.

You should no longer get a blinking/flashing wait to start light when usingthe one piece design. The box should no longer go into default mode.

You no longer will need to troubleshoot the temp sensor/controller if you

have the one piece design installed. However, be sure to keep the tempsensor/controller installed and connected.

Still need to make sure glow plugs are in good working condition - no need

to automatically replace them, just check them.

Ensure that your connections to the body and engine side are good and tight.

The voltmeter will still fluctuate during after-glow activity.

Bottom line - the one-piece design is the same as two piece design exceptfor the temperature sensor.

If you suspect a problem with the starting system (control box):

Check batteries

Check all 8 glow plugs

If Wait to Start Light does not come on, but you had voltage gauge activity- attempt to start vehicle. If no start, check fuel system.

If Wait To Start Light comes on and you have voltage gauge activity, andstill get a no start - your control box should be functioning, problem maybe fuel related - check fuel system.

If no Wait to Start Light, no glow plug activity and no vehicle start; andall 8 glow plugs are good, wait to start light is good and connections atthe body and engine side are good and tight, batteries are good – replacecontrol box.