Troubles with M35A2

[tsjones]

Anyone know where I can get a set of bows for my M35A2? Also, have a problem with batteries draining all the time. Have changed batteries and added a new alternator, Still having problems,

 

[Armada]

Welcome!
For bows, check out http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6593562127&rd=1&sspagename=STRK:MEWA:IT&rd=1
My brother has the same problem with a parasite drain on the batteries. He never could find the problem. He ended up putting in a quick disconnect at the batteries.

 

[clinto]

I tried to look in the TM, but I can't open it, says the file is flawed or something. My TM is at home, I am at work.

This is how I have diagnosed parasitic battery drains.

Using a testlight or a multimeter, check the negative post of the battery. If there is a draw (current flowing) you'll get a light.

With the test light on, start removing one fuse at a time. When the light goes out, you've narrowed your search. Now, make your way down that circuit and do the same thing with anything that can draw current. Eventually, you'll find it.

I had an issue with my '65 Belvedere where the battery would go dead after w few days. I traced it back to a bad connection for the clock, which was causing it to draw a lot of current and run the battery down.

Stupid question, but do these trucks have fuse boxes? That's why I tried to look at the TM, but like I said, I couldn't open it....

 

[G744]

Fuses?

Right idea, wrong application. Other than the one in the stock fuel pump, there are no fuses in a duece. Only breakers.

The best way is a ammeter in series with the + battery lead (s). It would be easier to read if it were say a 0- to 1 Amp scale. All switches off for the first test.

Connected thusly, you should read some current flow. If not, set light switch to "stop light" and read again. Most mystery drains are in the lighting system with water or damp the culprit. The stoplight switch could be a suspect.

It could also be leaky diodes in the alternator.

dg

 

[da_sgt]

There's one fuse, it's on the fuel pump on the tank

 

[SixBuy]

For leakage too low to show up on an ammeter, disconnect the negative battery lead and read the VOLTAGE between the Negative battery post and the wire you removed. ANY reading indicates a leakage path SOMEWHERE.
Has anybody posted a copy of that schematic Peter Bog did a while back? That was a work or art that needs to be in everyone's tool kit! If not, I have an original copy but no good way to scan 11 x17. If you need a copy, PM me and I'll drop you a Kinko's copy in the mail.

 

[DrFoster]

We had problems of batteries dying in the Marines. We found that using a small piece of rubber beneath the batteries, and using those cheap solar powered battery maintenance devices / chargers the problem went away.

I don't have the greatest confidence with the lead-acid interstate batteries we used. They were the #1 reason a vehicle went to the deadline.

 

[mangus580]

Sixbuy... see if kinko's will just scan it to a pdf for ya?

If not, maybe they can shrink it to a smaller size that you can scan..

 

[SixBuy]

Good idea! I keep forgetting this is the 21st century... They can probably do that at the dry cleaners! LOL So I'm assuming the schematic never made it on line? Peter Bog did a magnificent job redrawing that in auto CAD. It would be a shame to lose it to time.

 

[DrFoster]

Another thought on this was from my friend that is still Active Duty. He mentioned to check the electrolyte levels, check the alternator's field coil for constantly being powered (suggests a bad "ignition" switch), and if you have a non-sealed battery, look into the fill holes with a flashlight and see if there is sediment in the battery, wich causes it to discharge slowly. Hope that helps.

 

[houdel]

That rubber mat under the battery sounds like a good idea to me. I remember reading some place (possibly a GM manual or some such thing) that lead acid storage batteries should not be stored on a concrete floor as it will cause current leakage and eventually discharge the battery. No idea why, but it seems to reason a steel battery box could/should do the same thing.

 

[DrFoster]

An insulated battery box does WONDERS in the winter too. Remember that lead-acid batteries have to keep a certain temp (around 70-80 I think) to stay "healthy". They do most of that on their own, almost like burning calories!

They'll use their own heat and energy to keep each other warm during those long cold nights and loose less to the weather.

Straight away, cold can kill a brand new L/A battery. I wouldn't go and spray a whole can of that foam filler in there (Seen it happen and couldn't believe my eyes...) but maybe a little extra fiber fill from your attic insulating project this summer? I'm not sure what would work best... Honestly, I'm a better people doc or turbo doc.

 

[ida34]

The battery discharge on concrete is an urban legend. Modern batterys will not discharge when left on the concrete ground anymore than they would normally discharge from being placed onto wood or other materials.

 

[emmado22]

Sounds like one for MythBusters!

 

[cranetruck]

Not sure about the regulator in the alternator, but the regulator for the 25A system (separate on the firewall) has a circuit that senses the presence of the battery plus a capacitor that are always using a small amount of current. The total drain is in the order of a milliamp or so, but if the capacitor has failed, the drain could be higher.
To verify, break the connection at the regulator by unscrewing the right connector (as you are facing the regulator).