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Alternator altering
- Thread starter Maina
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reddog90
SILVER Star
Does anyone know what load a reman 80 amp 3fe alternator can handle?
I'm trying to determine if I can run a 50A fused 6GA line from my battery to the drivers compartment of the truck to charge a goal zero yeti that would sit in the back of the vehicle. Will I burn the alternator out prematurely doing this?
I'm trying to determine if I can run a 50A fused 6GA line from my battery to the drivers compartment of the truck to charge a goal zero yeti that would sit in the back of the vehicle. Will I burn the alternator out prematurely doing this?
reddog90
SILVER Star
Theoretically the yeti I am looking at should power the fridge a little over 2 days on a full charge. I generally drive each day on a wheeling trip. So the alternator would be topping off the yeti from the fridge's demand overnight. And these trips are few and far between in my current season of life.
And he's right. Pushing its current limit for long periods will overheat the rectifier diodes and cause them to fail, and in many cases will take the voltage regulator with it. If you know how to change them it usually isn't difficult to do (done it on my 120A several times until I sourced good Denso parts), but it's still a chore regardless.
Hey y'all, poppin' in to follow up on the swapping of the FJ60 alternator fan onto the FJ62/80 alternator. Have a rebuilt FJ62 alt and my old fan from my FJ60 alt and was recommended not to do the fan swap. Has anyone who swapped fans had any issues at all after running that set-up for awhile? Seems like an easier route than grinding, welding, or cutting but I'm new to auto electrical and don't want to fry my newly rebuilt alt. Thanks for sharing your experience with the fan swap in advance!
- Joined
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Photo of FJ62 alt (80-90amp) fan in hand (on left) and FJ60 alt (55-60amp) fan placed on FJ62 alt
Thanks for the quick reply. It is slightly smaller but it brings air in the same direction. Size difference might be key here?
Alternator altering
Since this seems to be the main thread on this conversion, I will add my data point. Rock auto came through with a Denso 80 amp alternator, pulled the plug off a 1991 Toyota pickup at the junk yard. Then came the fun part. Extended the tensioner bracket 3" hole to hole. Also pulled the double...
forum.ih8mud.com
7 years later no issues with the trimmed fan blades.
quick bump. I did this mod yesterday and it went super smooth. I'm wondering what everyone is seeing for voltage output on the Remy alt though? I installed a brand new battery at the same time and im currently seeing between 13.7 and 13.9 volts across the batt with the engine running at 1500 rpm. This is a touch lower than the 14.7 that's the norm for most vehicles. I didn't check with the old alt so I've got nothing to compare it to.
I’m mid-process in doing this. I ordered the Remy from Rock Auto, they sent me the correct box but with the 1FZ 90A alternator. Sent that back and ordered one of the other ones that showed a Denso core - Pure Energy 14461. Got the correct 80A alternator but it’s not a Denso. Looks like a newly manufactured generic unit. Maybe the Denso cores have dried up.
Notes:
1. The mounting ears for the lower bracket are spaced perfectly. There’s about 0.5mm of wiggle, but that goes away when the long bolt is tightened.
2. The plug on the alternator body is different and in the box was an adapter to go from that to the 80 Series connector. I got the adapter harness from @Coolerman (really nicely built!), but I have to use the provided adapter as well since Mark’s adapter doesn’t fit into the alternator - two adapters in a row! I’m actually just going to repin Mark’s thing into the plug that goes into the alternator.
2. I had to trim the fan blades like @NookShneer (I think it was you that did that a few pages back Dave) so they didn’t hit the bracket. I really don’t want to mess with changing the bracket and getting too involved with the fitment. No turnbuckle bolts or other craziness like we’ve seen in this thread. Side note: the fan from the 60 alt doesn’t fit, I tried.
3. The alt came with the double row pulley. I tried putting the 60 alt pulley on the new alt, but it’s too thick and doesn’t leave enough threads for the nut. The double row would need chopped in half as seen above except…
4. I had a smaller pulley laying around that the local old-school alternator repair shop gave me a couple years ago. It’s a smaller diameter one the guy let me have so I could squeeze more low rpm juice out of my 60 alt. It fit the new alt perfectly and left enough threads for the nut. I guess I’ll have more juice, plus more at low rpm now. Hopefully the faster internal rotation doesn’t overheat the alternator at high rpm.
5. In order to use the stock adjuster bracket, I need a smaller belt. I have the Saginaw steering pump with the skinny pulley (I really wish we could find a stock-width pulley for that) and a Gates 1575mm belt. I guess I’ll try their 1525mm belt to start and go from there. Anybody have advice on belt length for this operation with a Saginaw steering pump?
Maybe I should just copy the adjuster bracket in CAD and make it longer. That would sure make this whole thing much easier.
Notes:
1. The mounting ears for the lower bracket are spaced perfectly. There’s about 0.5mm of wiggle, but that goes away when the long bolt is tightened.
2. The plug on the alternator body is different and in the box was an adapter to go from that to the 80 Series connector. I got the adapter harness from @Coolerman (really nicely built!), but I have to use the provided adapter as well since Mark’s adapter doesn’t fit into the alternator - two adapters in a row! I’m actually just going to repin Mark’s thing into the plug that goes into the alternator.
2. I had to trim the fan blades like @NookShneer (I think it was you that did that a few pages back Dave) so they didn’t hit the bracket. I really don’t want to mess with changing the bracket and getting too involved with the fitment. No turnbuckle bolts or other craziness like we’ve seen in this thread. Side note: the fan from the 60 alt doesn’t fit, I tried.
3. The alt came with the double row pulley. I tried putting the 60 alt pulley on the new alt, but it’s too thick and doesn’t leave enough threads for the nut. The double row would need chopped in half as seen above except…
4. I had a smaller pulley laying around that the local old-school alternator repair shop gave me a couple years ago. It’s a smaller diameter one the guy let me have so I could squeeze more low rpm juice out of my 60 alt. It fit the new alt perfectly and left enough threads for the nut. I guess I’ll have more juice, plus more at low rpm now. Hopefully the faster internal rotation doesn’t overheat the alternator at high rpm.
5. In order to use the stock adjuster bracket, I need a smaller belt. I have the Saginaw steering pump with the skinny pulley (I really wish we could find a stock-width pulley for that) and a Gates 1575mm belt. I guess I’ll try their 1525mm belt to start and go from there. Anybody have advice on belt length for this operation with a Saginaw steering pump?
Maybe I should just copy the adjuster bracket in CAD and make it longer. That would sure make this whole thing much easier.
Maybe contact ToyotaMatt for a SS Adjuster Bar to accommodate the 80 amp alternator and keep your 17mm belt. It also gives full adjustment which is limited with the stock bar and the 80 amp alt and the longer belt (I think it's 5640 mm ? I have to double-check). I haven't installed mine yet, but here's a pic:
Last edited:
My current belt is 1575mm, so I'm going to bet you're overshooting a little haha.
Yes, you're correct. 
I was thinking the BANDO part #, which is 5610 and 1575mm x 17mm width, with stock pulley and fan swapped onto the 80 amp.
I was thinking the BANDO part #, which is 5610 and 1575mm x 17mm width, with stock pulley and fan swapped onto the 80 amp.
I am running the Saginaw steering pump and the 80 amp Pure Energy Alt on my 83 60. I’am using this belt.
Here is picture of what I have left for adjustment with the stock bracket.
Not a lot but it leaves a bit left over.
That’s great intel. I was guessing a 9605 belt would be the ticket and I think that’s right. Thanks!
Hey mdw83fj60 - https://forum.ih8mud.com/members/mdw83fj60.185062/ , where did you get that pulley you have on the alternator? I've got the exact same set up and I want to get a more appropriate sized pulley. Thanks
That is the pulley that came on the alternator, I just cut the front row off the pulley.