Ferro- The Alternator slayer

[Ferroequinologist]

I'm really having some issues in the voltage generation department.

I'm had 6 alternators die on me in about a year and a half. Different brands, different trucks, different batteries.

Am I just a alternator killer? do I have 24vdc repellent in my blood? What gives?

I just installed a BRAND NEW one so I'd be good for Haspin, and it was running just fine. Went today to pick up Sevo's trucks, and the dang thing red lines and pegs out the gauge.

Am I destined to drive on batteries alone?

I've taken 3 to the local Electrical shop, and they say they can't get the voltage regulators anymore for them, or that they are very expensive.

Burned my first one up on the way home from Aberdeen 2007 in the M35, then the one in my first 109 burns up, then the one I replace it with burns up, then I get this 'new' 109, and the alt burns up, so I replaced it, then it burns up, now this one burned up!?!?!?!?

I've checked the wires, I've tested the batteries. What am I missing? Any hints?
The alternator that is in the truck now is pegging out at 33.3 volts. Batteries after shutdown are reading 26.4. Anyone have any ideas?

 

[hndrsonj]

Maybe you should do the 24V civilian replacements (guaranteed) that were posted here a couple weeks ago for 180$.

 

[Ferroequinologist]

I've been leaning that route, but I don't want to fry another one!

 

[hndrsonj]

Well at least if you fried it, you'd have a free replacement.

 

[avengeusa]

Well at least if you fried it, you'd have a free replacement.

hmmmm

give mine a try, and check to see if the charge wire from the alt to the starter solenoid post is not grounding to the frame.... or open, they will both cook an alt very fast, like within minutes......

I would run a new one to be safe

 

[gimpyrobb]

Have you swapped the batterys just to check? I would try a civy 24v one wire after that.

 

[Speddmon]

Have you swapped the batterys just to check? I would try a civy 24v one wire after that.

I agree. Put in some civy batteries, if you're just taking them to the local auto parts store to have them tested, the testers basically only look at the amount of current being put out by the battery. I'm thinking the big 6tl's could have a shorted cell or two and still put out enough current to make a relatively inexperienced tester user think they are good, due to the extra capacity of the larger battery. The testers have a sort of scale on them to rate the specified amount of current for a specific size of battery, since most people don't generally bring in 6tl's to test, the scales probably don't list them. A shorted cell is the quickest way to fry a voltage regulator. The easiest way to check for a shorted cell is to check the voltage of the battery while it's under a pretty heavy load. With a good voltage meter, you can check the voltage while under no load and it would probably read about 12.4 to 12.8 volts per battery (checking them one at a time). But put that same batter under a heavy load, like cranking a vehicle before it actually fires up, a good battery should read no less than about 11 volts give or take. If the battery drops down to 10 or even 9 volts then it's got shorted cells.

The circuitry in the regulator is designed to stay as constant as needed to charge your batteries, but the guage in the dash doesn't show the massive amounts of extra current that the charging system would be putting out to try to compensate for a shorted cell.

 

[Ferroequinologist]

thanks for the hints guys,

I took the alternators to the local large electrical rebuild shop, they had a huge test bench. They did also load test the two hawker batteries in the truck, they said they were fine. I watched, they had that load tester glowing red each time and each battery still read almost 12v.

I've had this issue with the hawkers, Interstate 6tls, and the Exide batteries in 3 different trucks. Am I just unlucky?

I will swap these batteries out, and check the pos wire from the alt back to the battery tray to insure no grounds.

avengeusa, this alternator is still generating, so if I can find and/or fix an exteral problem I will stick with it for now. Otherwise, you will be selling a kit. I'd order one right now, but I just have so many other things that I have to get first before Haspin, like, wiper motors.

It's just weird about the number of times it's happened to me.

 

[cranetruck]

The older separate regulator (25 amp generator), is protected from short circuit overloads and also open circuit conditions. However, a bad connection to the battery will create huge voltage spikes that can take it out. I still use the old 25 amp system and have added a few components to make it more fool proof...don't know about the alternator regulator, but it may not be protected from the "load dump" conditions either.

As suggested in a previous post, check the wiring harness for continuity and possible shorts to ground.

 

[Ferroequinologist]

Ok, I think I have a ground/draw somewhere. Took the neg cable off the batteries, and lightly tapped it to the post at night. got a light spark, like a car with a computer. Checked the horn, and some of the wiring in the engine compartment.

Anyone have an ideas? Light switch?

 

[Speddmon]

I'm not real familiar with the electrics on these machines yet as I haven't picked mine up yet, but I do remember reading a post about several people leaving their deuces sit for a few weeks without chargers only to find out the batteries are dead. That leads me to believe that it's not just you with a ground/draw, but every deuce out there????

Anybody know for sure? Just my


I was just scrolling through the -20 TM looking over the wiring troubleshooting section. Nothing jumped out at me as being a permanent draw, but you might just be able to start at the beginning and one by one disconnect each component listed and check for the spark at your battery terminal. If the spark is not supposed to be there you'll find it when you unhook the right part. When you find the culprit then you can determine if it's supposed to have a permanent draw or not....again, just my

 

[Ferroequinologist]

I was just scrolling through the -20 TM looking over the wiring troubleshooting section. Nothing jumped out at me as being a permanent draw, but you might just be able to start at the beginning and one by one disconnect each component listed and check for the spark at your battery terminal. If the spark is not supposed to be there you'll find it when you unhook the right part. When you find the culprit then you can determine if it's supposed to have a permanent draw or not....again, just my

Yeah, I was hoping not to have to go through the trouble of unhooking everything one at a time, especially as my harness is getting VERY brittle...

Hoping someone else had some experiances. Last time I had a ground, it was easy- it was that pos electronic light switch. I have the lever now.

Idea! I have a fluke with the current clamp, I could just trace the system and see where it is draining.

Not sure if this is what's causing my alt failure or not. But I'm pretty sure it isn't supposed to draw anything when sitting.

 

[Speddmon]

The amp clamp sounds like a good idea, is long as it's sensitive enough to pick up whatever leakage current you're seeing. Find each ground and meter each one to find your current. It's still a ton of work but better than tearing everything apart.