AC 6080 tach and battery question

[js2318]

Picked up an Allis 6080 recently and going through and fixing a couple of items - one of which is a non-working tach. From what I have read, this should fed from a leg coming off that alternator. It would appear alternator was replaced at some point and doesn't look to have a connector for the tach hookup. I assume either the black or green should go to tach and the only way to fix is to replace with correct alternator?

Also need to replace the start batteries. It currently has two 1250 CCA, which seems like overkill. Especially since started using a small portable jump pack, I can't find anything in owner's manual that says what size these should be. Google search says it is 30H size group . Wanting to replace with single battery and local NAPA has two available 760 and 950CCA. Any reason to pick one over the other?

 

[Bob Bancroft]

Picked up an Allis 6080 recently and going through and fixing a couple of items - one of which is a non-working tach. From what I have read, this should fed from a leg coming off that alternator. It would appear alternator was replaced at some point and doesn't look to have a connector for the tach hookup. I assume either the black or green should go to tach and the only way to fix is to replace with correct alternator?

Also need to replace the start batteries. It currently has two 1250 CCA, which seems like overkill. Especially since started using a small portable jump pack, I can't find anything in owner's manual that says what size these should be. Google search says it is 30H size group . Wanting to replace with single battery and local NAPA has two available 760 and 950CCA. Any reason to pick one over the other?

I agree, you probably need to source the correct alternator. For the tach AND hour meter to work, the key has to be on and the alternator turning. This time of year I expect any battery will start it. Earlier 6000 series were low compression and needed a little whiff of ether even in mild weather. They upped the compression so they started much better. The 760 CCA battery should be more rugged than the 950CCA.

 

[Jim.ME]

Use the part number to search with. From the 6080 parts book it looks like it would be either a Delco 1103165 or a Delco 1105423. It also appears those cross to the same number in at least some aftermarket replacements. It looks like this site may offer one.

 

[DrAllis]

That white plastic plug and the alternator should have THREE wires instead of two. I don't know what they did to the harness in that area because there is a wire not connected as I see it.

 

[js2318]

Yeah, I found the one on this site

https://www.yesterdaystractors.com/Allis-Chalmers-M2_Alternator_ADR0133.html

I will have to look at back side of the tach to see what color lead that is supposed to be. Wiring diagram I have doesn't match up with the color wires I am seeing. Assuming one of the cut off wires is really for the tach, that still leave an extra wire for something.

 

[DrAllis]

If you have an owners manual there is a good schematic in it.