3G alternator new or used?

[Gary Lewis]

I thought I had remembered something about how the 130 amp alternators were not good on the V belt pullys because of something to do with the belt? I understand you gotta swap the pullys, but other than that, there isn't any concerns going with the 130 amp?

I'm going to hopefully find a 90's taurus tomorrow at the junk yard.

A V belt won't transmit enough power to produce more than about 90 amps from what I've read. But it isn't likely you'll ever need that much current, so should be fine. Or, you can do a double-belt arrangement to the alternator, but it takes a bit of searching to find a crank pulley and alternator pulley with the right belt sizes and diameters.

[86-350-460-dually]

A V belt won't transmit enough power to produce more than about 90 amps from what I've read. But it isn't likely you'll ever need that much current, so should be fine. Or, you can do a double-belt arrangement to the alternator, but it takes a bit of searching to find a crank pulley and alternator pulley with the right belt sizes and diameters.

Okay. Thank you for that. So I should be happy with either the 90 or 130 alternator, if I find one tomorrow. Thanks.

[ArdWrknTrk]

I'm curious if that one fits the V belt or the Pully system? I have the V belt system.

None of the 3G alternators were made with V-belt pulleys, so i guess I misunderstood your question.

You are asking if the alternator I linked is 8.25" C-C, which fits a V-belt mounting bracket?

Yes. The 3.8l Taurus engine uses 8.25" mounting.

The 7" center ears do not allow enough adjustment swing to fit the V-belt mounts of the 460 and 300-6 engines of this era

The 3.0l Taurus engine uses the smaller 7" mount that fits the serpentine bracket of the Windsor pickup engines

As for belt slip with the large body (130A) alternator.

I always figured I'd rather have the better cooling diode board, and run it at 75% rated output than run the 90A unit at 100%.

Realistically, unless you have a big inverter or a winch you aren't likely to even stress the small body 3G.

The alternator will only load the belt as much as is demanded of it.

160, 130, 90, 60, any alternator will require similar power input to create similar power output.

The big advantage is that the 130A 3G can put out 65A at idle, where the stock 1 & 2G V-belt alternators need to be spinning much faster, and that is their limit before meltdown.

[Steve83]

I don't know how to put that stuff in quotes^

Click "Reply", then click the "Quote" button. Then edit down the quoted post to just what you're interested in. If necessary, copy & paste the quote tags to enclose each section that you want to reply to separately.

...a ballpark estimate of the price/alternator...

It depends on local availability & demand (like almost everything else). If the only people buying alternators from that JY are the scrap metal recyclers, prices are likely to be low. If there are plenty of alternators, demand won't raise the price much. But if used alts are popular & scarce, you'll pay more. To see prices in my area, check out:

http://www.pullapart.com/inventory/

http://www.lkqpickyourpart.com/locations/LKQ_Pick_Your_Part_-_Memphis-215/recents/

http://www.upullitap.com/inventory.aspx

For national prices (which are almost always MUCH higher than mine), try:

http://car-part.com/

But you can sometimes find parts MUCH cheaper on CL, LetGo, etc.

[Gary Lewis]

I'm curious if that one fits the V belt or the Pully system? I have the V belt system.

None of the 3G alternators were made with V-belt pulleys, so i guess I misunderstood your question.

You are asking if the alternator I linked is 8.25" C-C, which fits a V-belt mounting bracket?

Yes. The 3.8l Taurus engine uses 8.25" mounting.

The 7" center ears do not allow enough adjustment swing to fit the V-belt mounts of the 460 and 300-6 engines of this era

The 3.0l Taurus engine uses the smaller 7" mount that fits the serpentine bracket of the Windsor pickup engines

As for belt slip with the large body (130A) alternator.

I always figured I'd rather have the better cooling diode board, and run it at 75% rated output than run the 90A unit at 100%.

Realistically, unless you have a big inverter or a winch you aren't likely to even stress the small body 3G.

The alternator will only load the belt as much as is demanded of it.

160, 130, 90, 60, any alternator will require similar power input to create similar power output.

The big advantage is that the 130A 3G can put out 65A at idle, where the stock 1 & 2G V-belt alternators need to be spinning much faster, and that is their limit before meltdown.

Jim - I agree with you. But, there is one potential advantage to the 90A alternator - maybe not needing to remove the shunt to the ammeter. Since 70A alternators were available for these trucks, as I've recently pointed out on the Alternators page, the shunt must be capable of that much. Perhaps it could do 90A in a pinch?

As for the 3G's output at idle, you are probably remembering the RJM chart. Do you have a copy of that, or any chart showing 3G output vs RPM? I also added info on the 1G's output to the Alternator page and would like to add the 3G info but can't find it.

[Steve83]

...not needing to remove the shunt to the ammeter.

The shunt doesn't really go to the ammeter - it goes to the battery & all the electrical loads. The ammeter is ACROSS the shunt (it reads the voltage developed by current passing through the shunt's resistance, but displays that as an inferred amperage). So regardless of the alternator type (1G, 2G, 3G, 4G, Leece-Neville...), it's a poor circuit design and should be converted ASAP to a low-resistance wire (shorter & without all the connectors) & a true voltmeter. Most especially if you've swapped to a HO alt.

[ArdWrknTrk]

Jim you are probably remembering the RJM chart. Do you have a copy of that, or any chart showing 3G output vs RPM? I also added info on the 1G's output to the Alternator page and would like to add the 3G info but can't find it.

I'm sorry, no I never copied Ryan's pages.

irc Chris was part of the discussion of archiving that site before it disappeared.

Not sure if you could find those charts on the way back machine.

I know I had those URLs bookmarked on my long dead netbook.

 

[Gary Lewis]

Jim you are probably remembering the RJM chart. Do you have a copy of that, or any chart showing 3G output vs RPM? I also added info on the 1G's output to the Alternator page and would like to add the 3G info but can't find it.

I'm sorry, no I never copied Ryan's pages.

irc Chris was part of the discussion of archiving that site before it disappeared.

Not sure if you could find those charts on the way back machine.

I know I had those URLs bookmarked on my long dead netbook.

Steve - I agree that the shunt needs to be removed if you go to a high-output alternator as they have been known to melt when not removed. I recently replied to a post on FB where a guy said he'd burned his wiring up in that general area and I asked if he'd just done a 3G upgrade. He response was something to the effect of "Yes, how did you know?"

But I'm not sure a 90A 3G qualifies for "high output". That's about a 30% increase over what the shunt is probably rated since the trucks could come with a 70A unit. Perhaps the shunt would handle that? I don't know.

Jim - I'll contact Chris as I played with the Way Back Machine last night and couldn't find what I was looking for. But it would be good to find that chart and add it to the ones showing 1G output vs RPM.

[Steve83]

I agree that the shunt needs to be removed if you go to a high-output alternator...

I'm saying the alternator doesn't matter, period. I advise everyone to re-wire the charge circuit like a stock 3G's for better performance, more safety, and more functionality - even with a stock 40A alt.

[86-350-460-dually]

Steve - I agree that the shunt needs to be removed if you go to a high-output alternator as they have been known to melt when not removed. I recently replied to a post on FB where a guy said he'd burned his wiring up in that general area and I asked if he'd just done a 3G upgrade. He response was something to the effect of "Yes, how did you know?"

But I'm not sure a 90A 3G qualifies for "high output". That's about a 30% increase over what the shunt is probably rated since the trucks could come with a 70A unit. Perhaps the shunt would handle that? I don't know.

Jim - I'll contact Chris as I played with the Way Back Machine last night and couldn't find what I was looking for. But it would be good to find that chart and add it to the ones showing 1G output vs RPM.

In a twist of events, I do not believe the alternator went out. I haven't had a chance to check the alternator yet because I haven't gotten the truck up and running yet. Had the battery charger hooked up to the battery overnight, but I didn't realize it was only set for 120 min (timer). This morning, the battery was more dead than yesterday. We believe something is driving the battery (a light, a short, something...).

So I 'wised' up and disconnected the battery terminals this time and am trickle charging it all day and night tonight. The battery was so dead, I could not get a voltage reading on it. If I have a fully charged battery, I should be able to get the truck on and check the voltage with it running, and then hopefully search for whatever light is left on (maybe glovebox) or end up searching for some sort of short.

I don't know if I should feel relieved or frustrated haha.