1 wire alternator problems

[jmontes]

Good Morning - I am having a run of super bad luck with Tuff Stuff's 100A 1 wire alternators... since the rebuild, we have gone through 3 of these things in about 7K miles. They all start out producing 14+v but then one day will just stop working. Is there something and these Mustangs that don't like the 1 wire set up?

 

[Bentworker]

Are you pressure washing your engine bay or something?  Also- when are you checking voltage?  Most one wire setups won’t start generating any power until the engine is revved a bit to flash the field.

 

[tony-muscle]

I don't know about their alternators but I had bad luck with their steering pump. I think their stuff is not any better than buying a whatever brand from ebay. I have had good luck with my DB Electrical. I also have their starter motor. This brand has very good reviews. However, maybe there is something else in your system that is not working well with the alternator.

 

[Galucha]

What does your wiring look like from the alternator to the starter relay junction/main harness yellow wire? Sounds like you've got wiring issues somewhere other than the alternator itself.

Also would strongly recommend running a 100A inline fuse, if you're not already.

 

[jmontes]

Are you pressure washing your engine bay or something?  Also- when are you checking voltage?  Most one wire setups won’t start generating any power until the engine is revved a bit to flash the field.

No pressure washing... Voltage check is well after the car has been running for a bit. It is not an "exciter" issue. Also have a volt meter in the dash... Thanks for the thoughts and response.

 

[jmontes]

What does your wiring look like from the alternator to the starter relay junction/main harness yellow wire? Sounds like you've got wiring issues somewhere other than the alternator itself.

Also would strongly recommend running a 100A inline fuse, if you're not already.

All of the wiring under the hood is all new as i had to add relays to run the EFI, electric fans, and electric fuel pump. The only wire that was reused from the underhood harness was the ignition switch.

 

[jmontes]

I don't know about their alternators but I had bad luck with their steering pump. I think their stuff is not any better than buying a whatever brand from ebay. I have had good luck with my DB Electrical. I also have their starter motor. This brand has very good reviews. However, maybe there is something else in your system that is not working well with the alternator.

Thanks! I run DB Electrical 1 wire alternators in my boat and have never had an issue... I'll take a look.

 

[Bentworker]

No pressure washing... Voltage check is well after the car has been running for a bit. It is not an "exciter" issue. Also have a volt meter in the dash... Thanks for the thoughts and response.

Running at idle for a while- or are you getting it above 2000 RPM?

 

[jmontes]

Well above 2K... 

Like I said, been through 3 alternators. They all have charged at 14+ volts upon initial install and stay there with all the lights, wipers, A/C, electric fans, and stereo on. They will perform flawlessly for a couple thousand miles and then one day just drop down to 9-12v and stay there. None of them ever go to zero. 

Voltage checked on the Alt. stud with a multimeter as well as confirmed on the aftermarket dash mounted voltmeter.

 

[tony-muscle]

Also would strongly recommend running a 100A inline fuse, if you're not already.

Not going off topic too much, but can I ask what inline fuse holder are you using? I started with one of those clear ones and it broke. I am thinking of going to a breaker type.

 

[Don C]

Clean the battery terminals, clean the ground connections from the battery to the fender apron and the block. Don't just look at them and think they're OK, corrosion can be causing your problems. While you're cleaning the connections check the condition of the terminals on the cables. If they're more than 3 or 4 years old you might want to replace the cables, hidden corrosion in the terminals and cables can cause your problems.

 

[Bentworker]

The regulators in a one wire alternator are plastic coated magic.  It would be interesting to have an alternator shop go through your latest kill and see what the autopsy reveals.  I'm also curious what platform they are built off of.   Many of the one wire alternators are 10SI clones.  Would be neat to know if you are wiping out rotors, brushes, regulators, diodes, or windings.

 

[Galucha]

Not going off topic too much, but can I ask what inline fuse holder are you using? I started with one of those clear ones and it broke. I am thinking of going to a breaker type.

I'm running this one from painless. Have it mounted on the fender near the starter relay.

https://www.summitracing.com/parts/prf-80000