Wait Light Issue

[52C1retired]

HMMWV Owners: I'm working on a 1985 M998. The wait light just flashes and doesn't stay on. It has a KDS EESS black box in it with the proper yellow stripe temp sensor. I've read some of the posts indicating how to mitigate this issue. I changed out the box with a new one and replaced the temp sensor and installed a new set of glow plugs (six of the old ones tested bad). I cleaned the main ground cables and wires and cleaned the firewall ground wires. There is already a supplemental ground to the black box. I charged the batteries which both test good. After doing the above things, it still just flashes. It will start after two or three attempts with a large amount of smoke that clears up immediately after starting. I live in Arizona and I grant you it's over 100 degrees here, but the wait light should still stay on upon initial start up. Any suggestions from some of you experts???

 

[papakb]

Please go back into the right side of the "HOME" bar and do a search for this topic (see mthe magnifying glass). There are already 100 postings about this that you can read and see if any of them answer your specific question. We just don't need another one. I realize this is an initial post on your part and being new to the forum you aren't familiar with everything you can do here so all if forgiven this time, but the search bar really is your friend!!!!!!!!!!!!

 

[Milcommoguy]

Here's where a "flow chart to start" would be handy.

Flash - blink - on - off - hiccup - burp - fart - smoke and choke....

Don't use the box... so can't help, CAMO

 

[Action]

............., but the wait light should still stay on upon initial start up. ..........

Ah, no. It does not stay on after startup. You don't start the motor until the light goes out. It means WAIT.

 

[twisted60]

I seam to remember a blurb in the -10 about the light will only flash on then go out if over 120 degrees. My '86 M998 6.5 did the flash on then go out but turned out to be the batteries, put new batteries in and problem gone. Find the trouble shooting tree and follow it, answer the question down the line and you will find your answer.

 

[Bill Nutting]

HMMWV Owners: I'm working on a 1985 M998. The wait light just flashes and doesn't stay on. It has a KDS EESS black box in it with the proper yellow stripe temp sensor. I've read some of the posts indicating how to mitigate this issue. I changed out the box with a new one and replaced the temp sensor and installed a new set of glow plugs (six of the old ones tested bad). I cleaned the main ground cables and wires and cleaned the firewall ground wires. There is already a supplemental ground to the black box. I charged the batteries which both test good. After doing the above things, it still just flashes. It will start after two or three attempts with a large amount of smoke that clears up immediately after starting. I live in Arizona and I grant you it's over 100 degrees here, but the wait light should still stay on upon initial start up. Any suggestions from some of you experts???

First off, welcome the site. I only have one Diesel truck and it doesn’t have glow plugs so I won’t be much help to you.
Do you have the Technical Manuals (TM’s) yet? If not, go to forums above, scroll down to “Present Conflict Vehicles” in this forum you will find the TM’s for your vehicle. I’m not very good at navigating the TM’s, but with a little patience you will find trouble shooting guides for just about any problem. I have learned a lot about my trucks reading sections of the TM’s while looking for some specific info.
Take some time to learn how this site works. The search feature is very helpful. If you get stuck, ask for help. There are very knowledgeable folks here that will help you.
welcome aboard!

 

[TOBASH]

Wait light is what it states. WAIT.

when the light is out... Start and forget.

 

[JetbikeAnt]

Check the AC Tap Voltage at wire 2A. if its 24 Volts you Glow plugs will stay on until they burn out. Also, do a quick resistance check on your new Glow Plugs. They should read around 2 ohm's.