Cranking amps

[usma41]

What is the required cranking amps of both 12 volt battery's in an M38???????? Combined

[wesk]

Not sure what you are expecting for an answer!

If it's about battery ratings then the correct 2HN battery is rated at 150 Cold Cranking Amps (CCA) at 0 degrees F. Since they are used in series that makes it 300 CCA total.

If you are asking about starter cranking amps that must be meaured accurately with the starter on a test bench.

[usma41]

Wes, my M38 has two new batterys in it and it starts everytime , but it is like slow motion starting. I can start it in the morning and when I hit the starter it's like a dead battery, if I keep pushing the starter (about five times) it starts rotating slow then speeds up then starts. The batterys are not low.

[wesk]

I do not know your mechanical abilities but let's give it a shot.

1-Determine accurately (digital VOM best) that the batteries are in fact fully charged. About 25.5 volts.

2-Ascertain that all terminals are clean (CORROSION FREE) and tight. (All 4 battery terminals, the battery ground connection, the starter switch terminals and both ends of the ground strap at the right front motor mount.) If you suspect any of the battery cables to have corrosion inside the terminals where the wire is crimped you must check them with an ohmmeter or via the voltage frop test.

3-Ascertain that the starter mounting bolts are tight and the front support bracket and it's bolts are tight.

4-If 1, 2 & 3 check OK then pull the starter. Open up the switch assembly and look for corroded and burned contacts.

NOTE: If you are confident of your abilities a quick test at the beginning is to use a jumper cable from battery cable side of the starter switch to the post that goes inside the starter. This will tell you right off the condition of the switch but is very dangerous if not done carefully.

5-If all the above check OK it's time to take the starter to your auto-electric shop.

[RickC]

Is it odd that my M38 starter seems to turn a lot slower after its been run for a while?????
Rick C

[usma41]

Wes, before I do all that, I suspect that the battery's may be overcharged. This could have happened because of a bad voltage reg. setting. I will have them checked out by a pro and let you know. I put a charge to them and the overcharge protection on the charger kicked in.

[Niclas]

Wes, before I do all that, I suspect that the battery's may be overcharged. This could have happened because of a bad voltage reg. setting. I will have them checked out by a pro and let you know. I put a charge to them and the overcharge protection on the charger kicked in.

It happen when the battery is low on power (Amps)
I can get it sometimes when I charge a empty (drained) battery.

I would
check the status on the ACID.
(dont forget to use the correct battery water.)

the battery should be stamped with a mfg date.

/N

[PK]

What is over charging the batteries? How do I test for it? How can I check the generator regulator to see if it is doing what it should?

I am experiencing the same condition, explained in this post, with my M38. I usually keep a trickle charger on the batteries. When I start the M38 for the first time of the day it usually starts right up. Often if I shut it down and try to restart it, it seems as though the batteries are dead. I have been able to keep cranking it and get it started. I have checked the termials and ground. I had the starter checked by a starter shop and it checked out ok. I have checked the battery fluid levels.

[wesk]

Need more data. Do you have a completely stock 24 volt M38 or is it modified electrically?

Is your ignition timing set correctly.

Get a digitaL voltmeter. If you have a stock M38 place the positive probe on the starter's battery terminal and the negative probe on the frame or block. You should read at least 24.5 to 25.5 for a charged battery. Have a buddy start the engine. During the time the starter is cranking record your lowest reading. Once started you should read about 24.5 volts. Now accelerate the engine to about 2000 RPM. You should now read about 27.5 to 28.5 volts.

Let us know what you get.