Odd starting problem; Bobcat e42 excavator

[KeithT]

Need some help from TBN community….

2016 Bobcat E42, new battery installed 3/2024.

Will not start unless I connect my jumper box. However, both advance auto parts in Napa have tested the battery and the results have been the same, It’s a good battery.

With my multimeter I’m getting full battery voltage to my starter. I have checked all the grounds that I can find on the machine. I have cleaned all the connections on the starter. I even installed a battery from my boat which I just use for a week solid on vacation without any issue And excavator behaved in the exact same way. -when I turn the key on, I do not get any lights to light up nothing at all. Even though the battery is reading 12.4 to 12.6 V. As soon as I hook my jumper up though. Everything lights up and it easily starts.

Any ideas? Really scratching my head in this one

 

[gengine]

A fully charged 12v battery should test at 12.7v-12.9v. The charging system, by way of the voltage regulator (built into the alternator), should be testing between 13 and 16 volts, dependent on what the battery needs. 16v seems high to me, but that's what I was taught in a class. Normal high to me is 14.5v. Anyway, corroded wires and/or terminals will keep the amperage needed for starting from getting to the starter. Grab a battery terminal brush and clean the battery posts and the clamps, the shinier the better. If there is one of those replacement battery cable clamps, where you strip the wire and clamp the copper strands to the battery clamp, replace it with a solder type and heat shrink tubing. Also check the negative wire at the battery and the engine block, making sure they are clean and shiny. But, since it starts with a boost, its almost certainly a connection problem between your battery post and your cables. I usually find that someone has over tightened the clamp, so instead of full contact all the way around the battery post, the clamp is "egg" shaped, only making good contact at two points on the battery post. A multimeter will show you getting full voltage, to the starter, but your amperage can't get there. Think of water in a hose. Yes, you have water from the battery to the starter through the hose, but with a slight kink in the hose, (the egg shape on a round post vs. full contact around the entire post) the volume of water (amperage) can't get to the starter.

 

[KeithT]

Thank you for your reply, I’ve cleaned and re-cleaned the battery terminals. And I’ve taken every ground off that I can find and clean those as well. I guess it’s possible there could be some corrosion in the positive terminal. Where is connected to the wire? It’s the stock Battery cable not a replacement terminal clamp.

 

[KeithT]

A fully charged 12v battery should test at 12.7v-12.9v. The charging system, by way of the voltage regulator (built into the alternator), should be testing between 13 and 16 volts, dependent on what the battery needs. 16v seems high to me, but that's what I was taught in a class. Normal high to me is 14.5v. Anyway, corroded wires and/or terminals will keep the amperage needed for starting from getting to the starter. Grab a battery terminal brush and clean the battery posts and the clamps, the shinier the better. If there is one of those replacement battery cable clamps, where you strip the wire and clamp the copper strands to the battery clamp, replace it with a solder type and heat shrink tubing. Also check the negative wire at the battery and the engine block, making sure they are clean and shiny. But, since it starts with a boost, its almost certainly a connection problem between your battery post and your cables. I usually find that someone has over tightened the clamp, so instead of full contact all the way around the battery post, the clamp is "egg" shaped, only making good contact at two points on the battery post. A multimeter will show you getting full voltage, to the starter, but your amperage can't get there. Think of water in a hose. Yes, you have water from the battery to the starter through the hose, but with a slight kink in the hose, (the egg shape on a round post vs. full contact around the entire post) the volume of water (amperage) can't get to the starter.

Well, you were right.

I took everything apart on the battery again. The positive terminal cleaned it till it was shiny as a new penny as you suggested. Then I took a large socket big enough to clear the post on the battery to really pound the terminal down tight onto the battery. Tightened it up and it fired right up. Did this before work so I haven’t really had a chance to test it multiple times but initial indication is, you were right. And I thank you For all your suggestions.

 

[Gord Baker]

Thank you for your reply, I’ve cleaned and re-cleaned the battery terminals. And I’ve taken every ground off that I can find and clean those as well. I guess it’s possible there could be some corrosion in the positive terminal. Where is connected to the wire? It’s the stock Battery cable not a replacement terminal clamp.

Your next move might be the Ignition and Solenoid Terminals. I would also try a known fully charged battery. I have seen batteries test full for Voltage but have very few Amps available. Think of the water anology. Tank full of Water (Voltage), pump and flow (Amperage)

 

[dodge man]

I’d get a load tester and learn how to use it. You never know if they know what they’re doing at the parts store. Just experiment with it a little and you’ll learn how to read it.

In your case you’ve discovered the problem hopefully.

 

[CoveredWagon2]

Need some help from TBN community….

2016 Bobcat E42, new battery installed 3/2024.

Will not start unless I connect my jumper box. However, both advance auto parts in Napa have tested the battery and the results have been the same, It’s a good battery.

With my multimeter I’m getting full battery voltage to my starter. I have checked all the grounds that I can find on the machine. I have cleaned all the connections on the starter. I even installed a battery from my boat which I just use for a week solid on vacation without any issue And excavator behaved in the exact same way. -when I turn the key on, I do not get any lights to light up nothing at all. Even though the battery is reading 12.4 to 12.6 V. As soon as I hook my jumper up though. Everything lights up and it easily starts.

Any ideas? Really scratching my head in this one

I had a similar experience with my 1986 Case 580SE Backhoe. My multi-meter showed 12v at the starter, remote battery lugs and battery. LED lights on my after-market power bank glowed as expected. I attached my jumper to the remote lugs and started right up! When attached to the battery I got nothing. All grounds looked good. I disconnected the ground cable from the remote lug and the cable fell apart. The corrosion was hidden by the heat shrink. It had just enough ground to operate the lights and test 12v, but not enough to start the machine!

 

[Little Red Tractor]

I might have missed something, but have you tested the starter. It's likely the most painful thing to deal with, but if you've eliminated the obvious, then it's likely to be culprit.
I do like the idea of a "known good" battery, though. It may be that the new one just doesn't push the amperage out.