LAU Technologies (no longer in business) produced a special version of protection control box (12379864, NSN 6110014467126) for the HMMWV which was installed as a modification kit. While not very common, some HMMWV owners may find their vehicles have the LAU Technology control box systems. The control box, or distribution box as it is labeled, can be identified by a second 14 socket connector located next to the engine wiring harness connector. This second connector was used with an additional wiring harness (12379865, NSN 6110014467124) for the glow plugs. The LAU Technologies control box design attempted to electrically control the glow plugs differently than the factory original design.
Check that the main engine wire harness still has the glow plug wires in place. If they have been cut off, the wire harness will have to be replaced/repaired.
The original version LAU designed control boxes, marked version 10, had serious defects which caused random engine cranking, fires, etc. A revised version 14 was said to fix the problems but the control boxes are now very hard to find should one need to be replaced.
A better solution is to change to the KDS Smart Start system.
The LAU Technologies designed box and wire harness can be replaced with the much newer design of KDS Smart Start protection control box and glow plug controller by following these steps:
Disconnect vehicle batteries.
Remove the LAU P/N 12379864 control box and 12379865 glow plug wire harness. This harness is not part of the engine wire harness. It has the eight glow plug wires and connects to the control box with a 14 pin connector.
Install the KDS Smart Start protection control box. The KDS protection control box has the same mounting footprint as the LAU Technologies control box.
Install the KDS glow plug temp controller that came with the KDS protection control box (they are sold as a matched set).
Make certain the control box mounting screws are clean, no rust or corrosion. Bad grounds will damage the control box.
Make certain the engine wire harness is in good condition. Shorts and bad connections will cause damage.
Make certain all 8 glow plugs work and are not swollen or melted. Defective glow plugs can damage the control box.
Install the 8 glow plug wires (orange boot on each wire) that are part of the engine wire harness.
These general instruction steps are intended as a guide only and Erik’s Military Surplus will not be liable for any results from repair work done which followed in part, or in whole, the above instructions. Contact us with any questions.