Excavator won't start. Round 2

[MossRoad]

This is why I love this forum! :thumbsup:

 

[WoodChuckDad]

If one of the diodes is bad in the alternator back feeding voltage to the anti restart relay. Eg the engine already thinks it's running so it doesn't let you"restart" the engine

Ok. Thank you. I will definitely check that out.

 

[WoodChuckDad]

This is why I love this forum! :thumbsup:

I agree completely. Without that kind of knowledgeable input, I would never come up with such a possibility.

 

[mike69440]

Could be the diode in the alternator that prevents the motor being cranked when running. I had to bypass it at the battery solenoid.

 

[skyhook]

At first I could not turn the key to the heat position. I torqued down on it and got it to move...the glow plug light came on and it indicated that it preheated. I turned the key back to the start position....nothing. I moved the key back and forth to the heat position several times and it loosened up.

Any suggestions?

This tells me your ignition switch may be burnt from overheating inside. You need a strong voltage to the starter solenoid to engage it. You may also have a relay that handles this voltage and it could also be the culprit. Not familiar with your machine though.

 

[WoodChuckDad]

It looks like firemanMike69 nailed it. I put the fusible link back in and disconnect the alternator. It starts. Reconnect and it doesn't. I tested this several times. Now I just need to bust up my knuckles taking out the alternator.

 

[WoodChuckDad]

Just as a follow up. The first quote I got for a replacement part was Komatsu brand $749 with a 250 core charge....so a net cost of $499. I had seen an aftermarket alternator online for 339. But as usual, my local Komatsu dealer was able to find a new aftermarket alternator for a much better price. I had them overnight it so I can pick it up this morning and get back to work tomorrow. Total cost should be just over $200. Rish Equipment Co. In Chester VA. I know they have locations in Virginia, West Virginia, and Maryland. I will try to give a follow up tomorrow night about uninstalling and reinstalling. Taking the part out was a pain.

 

[DJ54]

For the next time, check around for a good starter/alternator rebuild shop. I'm very fortunate to have one close. Standard rebuild will run less than $75 for anything I've taken him, unless the armature needs replaced. And, normally, is rebuilt and on the counter in 24 hrs. I've taken in a couple when he wasn't real busy, and did it right then, in about 20-25 minutes. I've even exchanged out a couple more common one's he had rebuilt on the shelf.

 

[WoodChuckDad]

For the next time, check around for a good starter/alternator rebuild shop. I'm very fortunate to have one close. Standard rebuild will run less than $75 for anything I've taken him, unless the armature needs replaced. And, normally, is rebuilt and on the counter in 24 hrs. I've taken in a couple when he wasn't real busy, and did it right then, in about 20-25 minutes. I've even exchanged out a couple more common one's he had rebuilt on the shelf.

The guy at the komatsu store swapped the fan belt wheel out for me and suggested I take the core to a rebuild shop here in town so I have it in the shed just in case. I am doing that next week. If I never need it, Good!