M-818 Won't Start

[ramato]

Ok,, so we had a few days of cold weax up here in the northeast. Been starting up the 818 every day just to run her... Temp got down into the 20's and I had to use the preheater... after following the proceedures on the dash plate it would not start...but when I looked at the batterys (2 catepiller 12v's), they were hot and positive terminal was smoking. shut it all down.. took a reading with a voltmeter on the each batter separately and both were in the 13 v range and coupled gave me the 24v... I put trickle chargers on them also to keep them up, yesterday the temp was in the 50's. tried to start, the starter worked...and it almost started..(did not use the preheater) but then stalled, went to start again and nothing...not juice to the starter and no dash lights.. what happened.... I first think that the preheater is shorted to ground...and the rapid heat up of the battery may have damage some thing in the starting circuit...got any ideas?
So anyone out there ever seen this....and can give me some T/S pointers?
also what is the best way to hookup a 12v/24v charger to assist in starting on 24v system?
Thanks to all in advance..
P.S. My Halftrack is just fine for starting in the cold...no preheater.!! LOL
-Rich

 

[Army Ed]

Personaly if your up in New England with me i would toss 2 more batteries in there.4 BAtteries are pretty much needed when its cold up here.When we had our M818's they had a tough time in the winter but using the preheater and having 4 fresh btteries they would start 99% of the time with no issues.Just a reccomendation

 

[Earth]

Check your battery connections for the starting aid. That is a 12v plug and has to be hooked up right--to the grounded battery. If it's hooked up to another batt or in your case the other battery, then you are frying the plug when it's on.

 

[ramato]

Thanks

I went back out and have been looking it over..seems that the wiring to the preheater switch may be wired up wrong. additionally now that the batterys have been run down I got them on a slow 12v charge, separately. I also looking to just putting in new batterys (4) and seeing what happens there.
thanks again.

Rich

 

[doghead]

The cold start/glowplug, heater is supplied with 12 volts. (not 24)

If it was connected to 24 volts, it is most likely your glow plug is burnt out now.

 

[Westech]

yeah if it was on the 24 volt its TOAST! not like that little POS does much of anything.. its a wast of time. I never even use mine. You MUST have 4 batteries in there or its going to smoke them. I only have two 6TL's in mine but its only used in the summer. And hard starting will cook the batteries. There was a TM bulletin on using 4 batteries in the 800's. If it is really cold out you can give the air cleaner inlet a snort of starting fluid, it wont hurt as long as its a little squart and you put it in the air cleaner inlet and not right in to the intake. It will mix with enough air to be gental in it.

 

[reb87]

when it gets down to under 20 degrees I use ether. I used my m818s all during harvest and am hauling soybeans to town right now. I shoot a good long squirt into the intake screen and then stand on the running board window down and run the starter with one hand and spray ether as needed to keep it running. During harvest when it was below 10degrees I had to spray a little more after it started or it would die I would give it small shots if it slowed down and sounded like it was going to quit. Once it had been running for 10 seconds it would run without ether. Im running two batteries.

 

[ramato]

more...is more...

The investigation continues..ok..batteries are charged...they are deep cycle Catipillar HD 's 12v, each reads 14 volts...all wires are correct and tight at all connections are clean....turn the battery switch on, and no dash lights, or head lights, (even when with a charger connected)...starter switch does nothing...no turnover so that has me thinking that a component has smoked somewhere in line with the batteries and the rest of the system...Which component?,,, I am waiting for tech manuals to get here so I can continue the work...unless someone has the answer or know what component I should check, or could get me to a starting wiring diagram online...
Btw.. my Halftrack and GPW still start...no problems..good thing for the guys back in the Bulge...
Happy New Year....to all

Rich

 

[BKubu]

My recommendation is not to try to start your trucks when it is that cold unless you have to do so. Why put the strain on the truck? Strange things happen when it is really cold out. Things fail that would otherwise be fine.

 

[Earth]

Your control box might be toast. You can override the solenoid on the IP, and pull start it. Someone just posted a few pics the other day on Gimpy's post about starting a 250 in a can. One of the pics shows the override screw.

I wholeheartedly agree with BK about no starts in the real cold. I only start what I need to run in the winter, and we park everything so we can plug it in. The 80 bucks for the block heater and the 350 bucks for the NAPA batts was money well spent because I need the truck to run whenever i need it.

 

[rosco]

Anything above 0f is not a problem for them. Putting heat on them is best. Check all battery connections now. Take them off, scrape them, and put grease/dielectric grease on them. Reb said it. Use either to get them going in modest temps. That is much better them grinding your starter away.

Lee in Alaska

 

[M813A1]

Also check your Battrey switch the switch may have gone bad and will not let your dash get power through the control box !! And like Rosco said check and clean the terminals and Ground lug on the frame !! Good Luck !!!

 

[Rene M]

I am a heavy Diesel Tech here in Texas but i can say that NA " non turbo" Diesel engines are hard to start cold. Very hard..
I am a firm believer that you should not use any type of starting aid " either etc" i have seen the damage first hand. AND ITS NOT A PLEASANT SITE.

Heat is what i recommend... Hair dryer heat gun etc laying on the intake or where the the engine can draw the hot air in. Just 10-25' of warm air will cut crank time down to nothing.

This is how all modern Diesels work, they use an air heater.

Just my 0.2

 

[ramato]

Back at Problem

Ok, so I finally got at the truck on this problem. I have 24volts from Bty to the starter, and then up wire (#81) to the back of the Battery switch on the dash. but then no voltage from switch via wire from back of Bty switch to the Starter switch. Which tell me it is the Bty switch that is bad. But now I am wondering if the control box is bad (as it may have been affected) I still get no dash, headlights or anything.

For background, I was starting the truck, and it was rolling over, and then all light and power stopped.?

Also are the fuses/relays resetable or need to be replace if they are bad.
any suggestions....

thanks

Rich

 

[jwaller]

the truck has auto resetting breakers. so if the trip you can cut power and the come back in about 15 seconds or less.

have you tried to manually open the fuel cutoff with the thumb screw and then use a jumper wire to turn over the starter?

 

[ramato]

J,
Thanks for the reply, yeah, that is the next step on sunday. I am having the battery switch tested today and get it back tommorrow. If it is ok then I go to the switch the fuel cutout and jump.
Rich

 

[OPCOM]

If the battery terminal was smoking then you have a bad connection there.

Rene M, please say more about these air heaters. Where to look up this technology? The M818 was the devil to start in 0-20 degree weather. Lots of cranking and lots of white smoke till it caught. Then it was just fine (no smoke runs perfect).

A hair dryer can take some 900-1600 watts to run it. But it seems that one could be hacked apart and put in the air cleaner or somewhere where it could just recirculate the air to itself in that closed space and heat it very nicely. This contraption could even be made to use the existing preheater switch.

The pre-heater never did me any good either. I think that either most of them are broken somehow or they just don't work. I measured 6V on the glow plug terminal, which is right according to the spec on the glow plug. The 12V must go through a resistor, and this has got to be a rather high-amperage circuit. The lamp seems to be a 12V or 6V lamp. Probably 6V like a #1847? if it is across the glow plug. But when the plug burns out (opens), the lamp will be blown out.

 

[cranetruck]

This diagram may help your troubleshooting.
Looking at the second diagram, wires #81 and #5 are connected only via the reverse polarity protection relay, so there is an error in the first one.
To have power for lights, dash etc, the reverse polarity protection relay must close.
Steel Soldiers :: Military Vehicles Supersite