alternator output 12.4V ... battery died ...thoughts?; repairs?

[reb]

Also wrong. 12.4 volts is battery voltage, and a less than fully charged battery at that. A functional charging system will show more than 12.4V when operating.

I am not familiar with all charging systems. On my 1500 (and probably most if not all these older Yanmars) there is only a wire between the regulator and the battery. Therefore only battery voltage will appear at the regulator output (ignoring the minor voltage drop along that wire). The voltage reading will rise to 13-14v as the battery charges, as LD1 stated.

 

[RickB]

I am not familiar with all charging systems. On my 1500 (and probably most if not all these older Yanmars) there is only a wire between the regulator and the battery. Therefore only battery voltage will appear at the regulator output (ignoring the minor voltage drop along that wire). The voltage reading will rise to 13-14v as the battery charges, as LD1 stated.

Pretty much what I said.

 

[BC Dave]

oh its a YM 180D; 18 hp; US model.

I was doing a very quick check on the alternator; the battery was already low; so 12.4 is ok considering it was on a car alternator for 1/2 hour; ... but with it running .... it was showing 12.4V; which I beleive was just the battery charge not a charge current ... will check all out as noted above.

Yep I ordered voltage regulator for $85 and alternator for $145 for Hoy (Lookied competitive and they do gaurentee the lowest prices; so let me know if parts can be found cheaper)so I'd have them on hand as the tractor is in a remote location 350 miles away with.

I'll update when I install and fix (hopefully) the problem ...

 

[LD1]

oh its a YM 180D; 18 hp; US model.

I was doing a very quick check on the alternator; the battery was already low; so 12.4 is ok considering it was on a car alternator for 1/2 hour; ... but with it running .... it was showing 12.4V; which I beleive was just the battery charge not a charge current ... will check all out as noted above.

Yep I ordered voltage regulator for $85 and alternator for $145 for Hoy (Lookied competitive and they do gaurentee the lowest prices; so let me know if parts can be found cheaper)so I'd have them on hand as the tractor is in a remote location 350 miles away with.

I'll update when I install and fix (hopefully) the problem ...

It doesnt matter if the battery is completely toast or not, if it is on a running engine with a WORKING alternator, it should STILL be showing 13.5-14V. IF not, then you have a charging system problem. The battery being dead is NOT the reason you are only seeing 12.4v

 

[clemsonfor]

oh its a YM 180D; 18 hp; US model.

I was doing a very quick check on the alternator; the battery was already low; so 12.4 is ok considering it was on a car alternator for 1/2 hour; ... but with it running .... it was showing 12.4V; which I beleive was just the battery charge not a charge current ... will check all out as noted above.

Yep I ordered voltage regulator for $85 and alternator for $145 for Hoy (Lookied competitive and they do gaurentee the lowest prices; so let me know if parts can be found cheaper)so I'd have them on hand as the tractor is in a remote location 350 miles away with.

I'll update when I install and fix (hopefully) the problem ...

Hoye is cheap on most stuff, sometimes there beat by a little off ebay, but Hoye is a great company and easy to talk to and fix an order if needed, ebay can sometimes be a pain, although i have yet to be burned the email part just takes time.

Also some of these parts can be found at autozone for fractions of the cost of yanmar parts. California has done a good bit of reasearch. Some of the volt regulators are off the shelf Nissan/datsun stuff from the late 70's as well as i know the alt of my ym 2000 he has found at Autozone for less than $50. Just need to take parts and have a clerk start pulling them or do some online research at Autozone.com and see what looks close then go there and have them pull those parts. Advance works to and i find advance to be cheaper these days.

It doesnt matter if the battery is completely toast or not, if it is on a running engine with a WORKING alternator, it should STILL be showing 13.5-14V. IF not, then you have a charging system problem. The battery being dead is NOT the reason you are only seeing 12.4v

I was never saying that the battery was his sole problem either.

Also to BC dave my point in this is yes there is a charging problem, your yanmar should at least give your 13+ volts at the battery while running. BUT this does not mean both battery and Reg are BOTH bad, one or the other can go out. The Voltage regulator is the most common thing to go down. Im just hate to see to many parts used as well as excess money that is not needed. But on the other hand other than batteries and wires you know your stuff is brand new!!