Alternator Regulator Replacement

Kinarfi · March 4, 2012

Steveoz sent me his alternator so I could see if I could revive it, I was successful, If your windings look good like in the first picture, it can probably be fixed with this method. I found an 8 pin regulator chip that requires no additional parts, except for a 1000 ohm resistor that needs to be put in line with the alternator plug, red wire only, the white wire should be disconnected. The housing for the original regulator has an embedded wire that needed to be cut, so I drilled into the housing and ground it in two with a dremel tool. The original regulator had 3 auxiliary diodes that the new regulator doesn't need and they were already fried anyway, just had to replace one with a piece of wire, as per the design.The red wire of the alternator plug supplies the alternator with the start up power when the key is on, but needs a resistor to limit the power in and prevent feed back which could possibly provide enough power to keep the engine running. The white wire carries a signal to computer- ( I think that's what it's for )

but because I do not know for sure, I recommend disconnecting it using the method shown in the pictures. The dash warning light seems to be powered by the computer and goes out when the alternator is putting out voltage, once it is running, the plug can be disconnected and it will keep working and the light will stay out.

The chip is a L9911M and I bought 3 of them from Digikey Electronics http://www.digikey.com/ for $10.96 each + tax and shipping. I did a photo journal about it if you want to do it your self or you can ask me to do it for you. This is the first of about 20 photos.

Kinarfi

sturmadin · April 9, 2012

Hello, recently tracked down a battery drain which I believe is related to my alternator. The alternator seems to still produce power 13 volts, but drains the battery when parked even with the battery disconnect key removed. I rewired the entire system with 8 gauge to make the key shut EVERYTHING off when removed.

Things I have noticed is a belt screech when I start, wondering if the alternator is not being properly energized? After reading a bit from this forum, sounds like I may have a bad alternator which could cause damage or breakdown further.

Any advice on what I should do?

-joe

Kinarfi · April 9, 2012

do you have a voltmeter that measures current? if not use a small low wattage 12volt light. WITH THE ENGINE OFF, Unhook the main alternator wire, THE BIG ONE and the 2 wire plug, now measure the current from the main alternator wire, IT'S HOOKED TO THE BATTERY, to the main alternator wire terming and again to the terminal where the red wire in the plug would go, if using a light, look for it to light or glow dimly.

sturmadin · April 9, 2012

Thanks for the response, but not sure what you are asking me to do. with the vehicle running probe across the main output terminal to which wire?

Kinarfi · April 10, 2012

Edited original post, reread it. What we are looking for is where is your current drain, I suspect one or two of your diodes in the alternator are blown. The last one I fixed had 3 of 9 diodes blown. You have 6 power diodes that take the power from the stator and rectify it to feed the vehicle and recharge the battery. There are 3 that take power from the stator to provide power for the regulator and the field. The alternator is supposed to make 14.2 volts and if your only getting 13, it not enough and you probably have a problem.

sturmadin · April 10, 2012

Thanks again. I will do this tonight. I am assuming that if I get light, there is a leak? What would you charge to rebuild this thing and how quickly can you turn it around? Joyner says they have them for 219.00 which is insane.

Can this also cause low idle/oil pressure? Last night after a quick run, at idle the oil light was illuminating and it appears to have no oil pressure. Give it a little gas and it climbs into tolerance and the light goes off. Oil full and only 18miles. sigh

lowgear · April 10, 2012

I have an 08 originally if the idle speed was below 950 the oil pressure would fall off to about 5-6lbs, but if I raised the rpm to 1100 it would climb to about 20lbs. I found out with mine that straight 50w oil it would maintain good pressure at idle even when hot. I don't think that your alt or battery voltage has anything to do with oil pressure. I now have 12,000+ miles on mine and it has not changed.

April 10, 2012

I run 15w50 mobile 1 synthetic. Mine holds good pressure at idle. You can always add an oil cooler. I have a 9 quart aluminum oil pan which keeps the oil cool ant the pressures up all the way, even in hard running. Oil pressure and electrical are seperate unless you have no voltage, then the oil light won't come on.

Lenny

sturmadin · April 10, 2012

Thanks guys! Off topic, but where did you get that oil pan?

April 10, 2012

Thanks guys! Off topic, but where did you get that oil pan?

I made it.

Lenny

rocmoc · April 10, 2012

Come on guys, got to ask Lenny how much he will make an oil pan for you!!

My oil pressure decreases at idle but is still in the ok range. I also run same oil as Lenny.

rocmoc n AZ/Mexico

sturmadin · April 11, 2012

Kinfari, was wrong on output voltage. I am making 13.9 at the battery running and 12.5 off. Using an optima yellow top 51. Will run your test tomorrow when I take the bed off for access. I think its going to fail your test. It was the only component left hooked up to the battery after I isolated everything else to the shutoff switch. (my trooper came with some weird wire running directly to the battery which kept a fuse "constant power" running even after the shutoff key was removed. Thinking this was not only wrong but could be the draw, I rewired it to the shutoff. Did not solve the problem.

Frustrated, I ran 8 gauge from the battery to the shutoff, and ran 8 guage back to the starter post, which is also where the feed for the alternator is. This obviously disconnects EVERYTHING with the shutoff key out, which I want. I am still concerned however that the bad alternator can cause other issues. Not my expertise. Appreciate your help.

-joe

sturmadin · April 20, 2012

Kinafari, Im sorry, im still very confused. My main alternator wire no longer goes directly to the battery. In aggravation, I ran 8 guage from the main terminal/positive post of the starter solenoid(where my alternator feed leap frogged to) to the to the cutoff switch. I ran 8 gauge from my battery positive lead to the other of the switch. The battery cutoff switch does exactly that now. The downside is when you take this battery key out, the buggy will run off the alternator making it useless as an emergency shutoff. I make 14.1 volts with the battery out of the loop and 13.0 with the battery connected.

I am losing my mind here. I took the battery key out, in essence disconnected the entire positive lead from the buggy, and a week later the battery was dead AGAIN. Nothing I have done fixes this drain. I monitered the charging system at idle for 30 mins and it never dropped below 13.0. The battery was low however.

Any other ideas? My understanding is with the postive lead of the battery completely disconnected, nothing can draw?

Kinarfi · April 20, 2012

Kinafari, Im sorry, im still very confused. My main alternator wire no longer goes directly to the battery. In aggravation, I ran 8 guage from the main terminal/positive post of the starter solenoid(where my alternator feed leap frogged to) to the to the cutoff switch. I ran 8 gauge from my battery positive lead to the other of the switch. The battery cutoff switch does exactly that now. The downside is when you take this battery key out, the buggy will run off the alternator making it useless as an emergency shutoff. I make 14.1 volts with the battery out of the loop and 13.0 with the battery connected.

I am losing my mind here. I took the battery key out, in essence disconnected the entire positive lead from the buggy, and a week later the battery was dead AGAIN. Nothing I have done fixes this drain. I monitered the charging system at idle for 30 mins and it never dropped below 13.0. The battery was low however.

Any other ideas? My understanding is with the postive lead of the battery completely disconnected, nothing can draw?

Sounds like you have it wired correctly, the battery cut off is just a battery cut off, not an emergency shut down and the vehicle will continue to run with that key out, won't start again though or any thing else until you put the key back, Here's a pain in the butt test, charge the battery by driving or charger and take it out of the vehicle, if it still drains your problem is the battery and unless those (I think you said you had a yellow top optima) optimas run differently, I doubt it, it sounds like you have a dead cell. you run at 14.1 which is normal, but with the battery in, you run 13.0, should be 14.1 also and when you shut down, it should hold 13.6 for a while as the surface charge drains off and stabilize at 12.6, each cell makes 2.2 volts, so if your only getting 13.0 while running, your overcharge 5 of the 6 cells which may or may not be contributing to the total. Take it out and set on some wood blocks and see if it keeps it's charge or take it in and have it tested.

Kinarfi

sturmadin · April 21, 2012

Thanks kinfari. I took the battery to 3 auto parts stores which ran every test imaginable, good battery. With the battery charged, I make 14.1 with the battery in the loop now. I am going to check the voltage and draw daily now.

Tinman · April 22, 2012

Kinarfi,

Every time i read your posts, I feel like I've drunk 5 too many beers. Obviously, you know FAR more about electrical systems than I every will.

Kinarfi · April 22, 2012

Thanks kinfari. I took the battery to 3 auto parts stores which ran every test imaginable, good battery. With the battery charged, I make 14.1 with the battery in the loop now. I am going to check the voltage and draw daily now.

You're making 14.1 now, but you were only getting 13 before, right? that sound like a bad connection that got fixed by taking the battery out and putting it back in. I've seen that before in connections, that's why I say to periodically pull all your fuses and relays and sockets and plugs and such and then plug them them right back in where they came from. My philosophy is that a connection get a little corrosion which generates some heat which creates more corrosion which creates more heat which ........ until melt down.

Tinman, just don't drive after reading my posts