I just wired my 1 wire 12 volt alternator the other day and noticed that is was getting hot just sitting there, I immediately went and unhooked it from disconnect switch. Why would it be getting hot? I have it wired to battery side of Master cut off switch. I know a 4 pole master cutoff switch would be better but would have to redo the whole mounting and push/pull handle and dont want to do that right now. I have always wired the alternators like this and havent noticed them getting hot.???

Likely bad diode in the alternator.

I do not know but most starter alternator shops can check it out for you. Quick and easy to do and they should know.

For the simple reason that I don’t want power at my alternator when motor isn’t running I mounted a constant duty solenoid beside my battery and ran the wire through it. It turns on with my ignition so when car is shut off it opens up the circuit. I know this doesn’t explain your issue but does prevent dead battery if your issue arises when master switch is left on.

Green1 I was thinking about something like a starter solenoid? Would that work or do I need a different kind of solenoid? I dont like having a constantly hot wire running from battery to Alternator all the time, just a fire waiting to happen. thanks

IRHAPSODY 4-pin 250 Amp High Power Relay, 12VDC Heavy Duty Continuous Relay to Switch Power On/Off, SPST 4 Terminals Automotive Electrical Starter Relay Split Charger Contactor at Amazon for $16.

Getting hot so I'd say it was drawing current. I had that happen to my 1 wire alternator and it drained my battery. Took it to local alt. shop and he rebuilt it for me.

quote:

Originally posted by Buck2248:
I just wired my 1 wire 12 volt alternator the other day and noticed that is was getting hot just sitting there, I immediately went and unhooked it from disconnect switch. Why would it be getting hot? I have it wired to battery side of Master cut off switch. I know a 4 pole master cutoff switch would be better but would have to redo the whole mounting and push/pull handle and dont want to do that right now. I have always wired the alternators like this and havent noticed them getting hot.???

What is the Amp rating on it?

quote:

Originally posted by Buck2248:
Green1 I was thinking about something like a starter solenoid? Would that work or do I need a different kind of solenoid? I dont like having a constantly hot wire running from battery to Alternator all the time, just a fire waiting to happen. thanks

Cole hersee constant duty solenoid.
Wire it so it comes on with the master switch.
A starter solenoid is intermittent duty and will eventually burn up.
Or the aforementioned 4 pole (4 large poles) master switch, and 16 bucks is definitely some China crap.
Less heavy wiring if you mount the solenoid up front and tie it in, then you just need a # 14 0r 16 trigger wire from the master.

If possible, contact the alternator builder. "Normally," it is not necessary to isolate the alternator.

If you do not know the builder, Mark Payne at House of Payne is a good source

Paul I’m not sure what amp it is it’s a east coast auto 2025 super mini

Mike like somebody stated starter solenoid will burn up, you need a constant duty solenoid and it needs to be rated for your alternator. I will try and remember to look tonight and see if mine has any part numbers on it.

I use a Cole Hearse constant duty relay on mine. It's mounted right next to the alternator. I can wire around it in an emergency if needed.

quote:

Originally posted by Buck2248:
Paul I’m not sure what amp it is it’s a east coast auto 2025 super mini

Website says it's a 55amp unit.

Mike I used a FTX201-100 continuous duty solenoid from competition products only 27.95 wired from alt to power distribution triggered by on off power switch been on car 6 years works great!

Ok, guys I sent ECAE an email about it, will see if they can answer what is up. I am going to order a continuous duty solenoid and install it anyways just for peace of mind. I had what I thought was a spare 12v alternator I was going to put on and try but it is stamped 14V so didn't know if that was a good idea? I have been running 16volt systems for years but cant fit anything but a lithium 16v battery on the battery spots on the car so had to leave it 12v. Thanks for all the info.

I think most 12 Volt alternators put out about 14 and most 16 volt alternators put out about 18 when charging. Maybe even a little more. Believe me someone will correct me if I am wrong.

all my stuff is 16V now but have been on various 1 wire alternators for many years. Every one wire will draw "some" current no matter if brand new or broken. They will all draw the battery down to nothing if left connected in the trailer for months. I've seen several do just what you mention, take it off get it checked/fixed, warm yes i could see, hot sounds like somethings wrong.

Several have mentioned the continuous duty solenoid with the 1 wire alternator, All of my recent builds have utilized this approach and its much better on battery health for when the car is in the trailer, also helps with between round charging/battery health (very little cause the amp draw should be very minimal, but still its a draw). I won't run a 1 wire alternator without a continuous duty solenoid to break the connection when not in service.

Future builds, i'll use a 2 wire, much easier and is actually the same principle. We all went after the 1 wire deals many years ago cause it was simple, now adding the solenoid makes it all complicated again and requires the use of 2 wires. If i had only listened to the guy at Jones racing many years ago when i bought my first mini, he wanted to sell me the 2 wire version, said it was better on the batter for long storage periods etc. I bought the 1 wire. Never again. 2 wire configuration eliminates the stupid solenoid.

Doesn't a 4 pole isolated CH eliminate the problem with discharging over long periods separates alternator from battery.

Yes it does.

quote:

Originally posted by BG7X77:
Doesn't a 4 pole isolated CH eliminate the problem with discharging over long periods separates alternator from battery.