New to M998s - Wait Light

[Austringer]

Have a 1993 M998, everything seemed to run fine until I noticed an issue about a week ago after apparently the vehicle was left in the "run" position overnight. Went out the following morning and found
1) both batteries seemed to be dead. (1 week old correct military batteries (Aug 23 production))
- One battery would charge normally
- Other battery, several chargers would not even see or attempt to charge
- Replaced the bad battery with a new one.
- The other battery might be replaced as it is hard to charge somewhat

2) After replacing the batteries
- The wait light does not light up
- The M998 starts after about 1 or so seconds of trying to start (even when it hasn't been started in a few days)
- The battery gauge shows it in the yellow (even when running, the needle is just north of the 2nd T- in the BATT stencil)
- Seems to idle a bit faster than I remember
- The blower fan in the cab does not seem to work (worked before the batteries were changed.

What does the group think the problem is and what checks and tests should I run? I do not have an STE-ICE. This is the 1st Humvee I've worked on, most of my experience are with M151s, M38s, V100s and M113A2s. Please advise.

Jason

 

[wheelspinner]

The wait light and heater fan not blowing are indicative of a start box issue. Same with the low charge gauge (probably not charging and showing battery voltage)

 

[Mogman]

As wheelspinner said, you likely fried the run relay in the PCB/EESS box.
Also one should always replace the batteries in pairs with the same size battery and battery build date for best results.

 

[Guyfang]

- Other battery, several chargers would not even see or attempt to charge

Try hooking another, (good) battery up in parallel to the dead battery, then hook up your charger. Often, when a charger "sees" not enough volts in the dead battery, it will not even attempt to charge it. If you have a good charger, it should at least attempt to start trying to charge it. After about an hour or so, you can unhook the good battery. Let it rip a day or two.