Why is my alternator doing this?

[Chowder Head]

Hey guys, I have something going on with my alternator that's annoying as hell.

For some reason, whenever I'm idling or my rpm are less then 2.5, maybe 3k rpm, the battery gauge will drop, and if I have lights on, they will dim, indicating the battery isn't getting recharged. But whenever I eclipse the mark of 2.5 or 3k rpm, the alternator kicks in, my lights brighten, and the gauge is straight dead middle.

I checked the replaced the alternator wiring and it's good. I even probed it with the multimeter and it's reading the battery voltage.

I was thinking since it's not the wiring, it's gotta be the alternator but this has been going on for a few weeks so it seems like if it was dying, it'd be beat by now.

And FWIW, the alternator is only a few months old and it's a 150 amp. Before deciding, I wasn't sure if the stock wiring could take the extra juice but the tech articles I read indicated from users that they had no problems.

So what do you guys think?

Any help would be swell, thanks.

 

[tording]

If you have upgraded to a 150 amp alternator then you should run another wire to handle the extra current. If your car is 87-93 then the wiring is only rated to handle like 80 consistent amps. I don't know if this is what is causing your light dimming issue but I am sure its not helping any. I would get a 4 guage wire and run from the alternator. Put your multimeter probes on the batter itself with the car idling and see what voltage you get. I have a 130 amp alternator and mine at idle is rock solid at 14.1 volts all the time. With all accessories on it drops to 14.0 volts. Hopefully this helps some. Good Luck

 

[HISSIN50]

We have a pretty good thread going right now with lots of great info about the importance of the wiring upgrade, and how to best accomplish the rewire.

Good luck.

 

[Sicarius428]

150A might be peak power at a high rpm. For example the Powermasters boast a high amperage but at idle they don't do squat. You may be drawing more than what the alt can produce at the lower rpms. The stock wiring is barely enough to handle the stock alt which was ford did a half @ss job with the dual fuseable links. Anything more and you are risking fire.
Kevin

 

[bullitstang1313]

Do you have several electrical loads like: stereo equipment, electric fan, etc. Are you running underdrive pulleys? Why was the alt replaced with the 150 amp alt. Have you had any other electrical problems. Its hard to tell the problem without more information. What is the battery voltage with the engine running at idle?

 

[Chowder Head]

Whoops, sorry guys, thought I had a sig here.

The car is a 95 GT so it already came with a 130 amp but when that one died, I was looking at one to get and was about to decide on a PA Performance 130 amp alternator when I found out a company called Tuff Stuff, which I looked up to see if there was anything wrong with them, had a 150 amp alternator for slightly cheaper.

Thinking more juice for less money, it seemed like a no brainer.

The main reason I got the 150 amp one is so if down the line I wanted to put in a new stereo system, I wouldn't have to worry about the lights dimming since 150 is more than 130. But hey, where I'm at now. Gotta love cars...

And if it helps, here's the kind of wiring I used. It's a link directly to the instruction page of tuffstuff.com. I used the bottom one because in those two drawings, my car had the plastic thingie and says "IMPORTANT" The only odd thing was that my plastic thingie had 3 wires going into it, not two like I guess it's supposed to. But since the first one didn't even seem like the one I should go with, I said screw it, and attached the blue metal strip into it's connector. And for about 2 months and a few more weeks, it worked perfectly fine.

However, I did have a slight problem after this. It will be kinda tough to explain but I'll try. A few weeks ago, I noticed the car not getting juice anywhere in the rpm. So I race home, pop the hood, and notice the blue metal piece that's supposed to be in the plastic thingie is out and two of the wires on the plastic thingie are burnt. Since this is my daily driver and can't afford much down time, I cleaned up the last and third wire, since they lead to the same place, and stuck the blue metal strip into the adjacent hole. It worked just as before (with the idle and lower rpm problem) but I couldn't help to wonder why it blew and if it was from the extra juice of the alternator.

And to answer questions, when car is idling during it's "no power" phase the voltage is 11.xx, clearly indicating it's not receiving the juice from the alternator. And I had a friend probe it when I revved it up into its "power" phase and it's an expected 14.xx

So what do you guys think? If it is the wiring, is there a quality site or shop I could go to get a complete wiring kit? And obviously, the cheaper the better.

Thanks a lot guys, I really appreciate the help.

Oh, and FWIW, my 95 GT is essentially stock with only an upgraded receiver in the electronics department. And I do not have underdrive pullies.

 

[bullitstang1313]

Alright, after looking at the wiring diagrams on tuffstuffperformance.com I don't think the blue wire would have anything to do with the problems. I think this wire is just used by the battery voltage gauge. I would upgrade the wires to the battery though. Most 3G upgrade kits use a 4 gauge wire instead of the 2 small wires. There is definately a problem if you are only getting 11 volts though at idle though. I'm gonna have to do a little more thinking.

 

[HISSIN50]

I'm lost on the link - I see info on Sports cards.

FWIW, I went from a 130 to a 160 on the '94 and it really didnt make a tangible difference. We can see there's an issue at hand, but for your edication, I'd want to see if an output sheet came with the alternator. Mine did and it lets you know that it tested out ok and what output it had at every 100 RPM differential.

I wonder if there's an issue with your regulator wiring. It's known to go bad on the 5N95's (the underhood heat bakes it). A new regulator plug is cheap and well worth it. IIRC, there are 3 wires on the regulator. Also make sure the stator wire is attached solidly to the stator receptable on the alt (it's the single wire that goes to the spade terminal).

Maybe you can help with getting us the directions you used because that seems key.

Good luck.

 

[bullitstang1313]

I'm lost on the link - I see info on Sports cards.

I had the same problem at first. Here is the link: Tuff Stuff

 

[HISSIN50]

I had the same problem at first. Here is the link: Tuff Stuff

Thank you.

Neither diagram is exactly correct for this application.

Here is the wiring pathway for a 94-95 3G alternator.

With a normal 3G, you have A, S and I terminals on the regulator.

S = stator

A = battery voltage. This can be connected to the PDC, the battery, or to the alternator charge post (it needs to see battery voltage, basically).

I = The switch wire. It's the wire that goes to the dash (battery/amp) light. The regulator ungrounds this wire when the alternator is excited (which makes the battery light go out. When the alternator is not spinning or has no output, the regulator grounds this wire, which makes the battery light come on.

I'm not sure exactly what you have done, so maybe this will provide the tools for you to fix it. I'd note that if a regulator wire was incorrectly connected, the alt might have been hurt.

Good luck.

 

[Chowder Head]

Thanks for that info. I'd figure since it actually was recharging at a certain rpm, I'd be fine for a little while until some more funds come in so I could fix it then.

Or so I though. Well, it just happened. I was driving out this morning, it did it's little thing about not working until 2k but when 2k rolled around, it still wasn't getting juice. I give it 1 more minute to start working or else I'm turning back and it didn't. ABS light came on, followed by the tach dropping, followed by me racing my ass home. Along the way, speedo dropped, radio dead, hell I even had to shut off the lights because I did NOT want to get stuck.

Luckily, I just made it home ten minutes ago and put the battery on a trickle charge of 2 amps. Damnit to hell....I had plans to go to Orlando this morning to go to Sea World because I have free tickets that expire the 31st.

So anyway, I have no idea what happened. I'm not sure if the alternator craped out, or the wiring didn't work. My question is there a SURE way to tell if an alternator is dead? Are the bench press tests from Auto Zone, etc, a reliable way of testing it out? I'd hate to send it back to company only for them to tell me it tests out ok, and that I essentially wasted the bucks to ship it out.

I looked at the wiring and it seemed okay but of course, since it's electrical, you can't tell anything by looking at it. Honestly, do you guys think my wiring is to blame or is it the alternator? If it is indeed the wiring, what is wiring that has the plastic doohickey that was shown in the install diagram of tuffstuff? (sorry for not pasting it)

Only reason why I've been reluctant is because if it is the alternator, I have to send it out and lord knows how long that will take. That's why I really considering buying one from the local store because of this reason.

Well I'm just babbeling now because frankly, I have no idea what to do. If I could get some feedback, opinions, facts, anything posted from anybody on how to fix this, I'd greatly appreciate it.

Much thanks in advance.

 

[Chowder Head]

Hey guys, I did a little searching and found something similar to my problem. It's from one of the tech questions at powermaster. Not exactly the same since they're focused on racing alternators but here it is.

"I noticed that my Powermaster one wire alternator has to be “revved up” to get the alternator to come on. Why?



A one wire alternator has a turn on point (sometimes called “cut in”, which is typically 1200 engine RPM’s). This is the speed where the internal sense circuitry connects the battery to the voltage regulator, thereby turning the alternator on. Once the voltage regulator turns on, the alternator will remain on and charging until the engine comes to a complete stop. If the engine idle speed and pulley ratio combination do not allow the alternator to come up to this point during starting, the engine will have to be revved up to turn the one wire alternator on. The sense circuitry in the one-wire regulator can be bypassed to excite the alternator as soon as the ignition switch is turned on. This is called three-wire operation. This means the alternator will not be dependent on reaching a certain turn on RPM."

Sorta sounds like my problem, no? Especially the part with the one wiring operation because that's what I believe I have. One blue wiring going into that plastic doohickey.

Just putting it out there.

Thanks guys.

EDIT:
Also found something else. A page showing wiring information from paperformance.com
http://www.pa-performance.com/searc...d+Wire+Kits&rqSku=&rqPartNO=&rqDesc=&rqOrder=

The wiring I got with my kit looks exactly like the bottom right. And if you view it, this text jumps out at me. "For those who want a “1-Wire type hookup” using this plug is the closest possible configuration to a 1-wire using a Ford 3G Series Alternator" 1-wire hookup, doesn't that seem like something from the powermaster tech question regarding the alternator not working until a certain rpm?

Sorry for the abundance of questions, it's just I really have no idea what to do. If I should replace the wiring, I'd like something that's not one wire so the charging is active all the time but I don't know what one to get.

Thanks again!

 

[seijirou]

Okay. You should have used the top instructions, not the bottom one. If you look at "The plastic thingie that's called important" That's called a D-plug. I get the impression that your new alt came with a new D plug. You should be able to plug in your factory wiring into the new alternator without using their new harness.

If you look on the instructions, at the picture of the alternator. Just to the right of that picture is the D plug, and just to the right of the D plug it reads, "White/black"

What I think happened based on what I'm reading, if you followed the bottom directions, but have a 3 wire D plug...

The new D plug is plugged into the alternator and hooked up like the instructions. However blue wire (switch wire) from that plug is plugged into your car's stator wire on the factory D plug... which is a problem.

Really I need to see a picture of how you wired up your alternator though. If there's any way get several pictures from different angles of how your alt is wired up, and if anything in there isn't right we'll do our best to walk you through the changes that need to be made.

 

[seijirou]

Haha, I meant to edit my last post. And I hit quote instead.

 

[seijirou]

Hey guys, I did a little searching and found something similar to my problem. It's from one of the tech questions at powermaster. Not exactly the same since they're focused on racing alternators but here it is.

"I noticed that my Powermaster one wire alternator has to be “revved up” to get the alternator to come on. Why?



A one wire alternator has a turn on point (sometimes called “cut in”, which is typically 1200 engine RPM’s). This is the speed where the internal sense circuitry connects the battery to the voltage regulator, thereby turning the alternator on. Once the voltage regulator turns on, the alternator will remain on and charging until the engine comes to a complete stop. If the engine idle speed and pulley ratio combination do not allow the alternator to come up to this point during starting, the engine will have to be revved up to turn the one wire alternator on. The sense circuitry in the one-wire regulator can be bypassed to excite the alternator as soon as the ignition switch is turned on. This is called three-wire operation. This means the alternator will not be dependent on reaching a certain turn on RPM."

Sorta sounds like my problem, no? Especially the part with the one wiring operation because that's what I believe I have. One blue wiring going into that plastic doohickey.

Just putting it out there.

Thanks guys.

EDIT:
Also found something else. A page showing wiring information from paperformance.com
http://www.pa-performance.com/searc...d+Wire+Kits&rqSku=&rqPartNO=&rqDesc=&rqOrder=

The wiring I got with my kit looks exactly like the bottom right. And if you view it, this text jumps out at me. "For those who want a “1-Wire type hookup” using this plug is the closest possible configuration to a 1-wire using a Ford 3G Series Alternator" 1-wire hookup, doesn't that seem like something from the powermaster tech question regarding the alternator not working until a certain rpm?

Sorry for the abundance of questions, it's just I really have no idea what to do. If I should replace the wiring, I'd like something that's not one wire so the charging is active all the time but I don't know what one to get.

Thanks again!

No you defanently have a 3 wire alternator. A one wire would literally only have the one output wire going to the battery, and that's it.

 

[Chowder Head]

Alright, thank you much for that information. I just went outside and snapped a few pics.

Here's the blue wiring being plugged into the D plug (lol, thank you)
View attachment 414423

A pic of the wiring harness I used that came with the kit showing where each wire leads.

Same shot as before, but different angle.
View attachment 414427

Now what you say sounds spot on and the only reason I didn't try is that is I had a problem before. Man, I've had everything so far...Anyways, a few months back, the lead wires ring terminal from the alternator (the fat red and black one in the pics) cooked itself and of course, it was the ring terminal, which meant when it happened, the alternator was essentially destroyed. Stator wire was burnt, etc.

If you can notice, the other two wires of the 3-wire D plug are either burnt or cut so really, I guess I had no choice but to run what I was running. I'll be.

Anyways, if you can spot the wires, here's a pic.
View attachment 414429

If I just need another D-plug stock style replacement, how is that done? Just get another one that has a wire long enough to splice back on the main wires leading from the fusebox area or where ever it comes from? So in the end, two wires are spliced back on the already present wires, the D-plug gets plugged into the 3=prong slot, and one of the wires from the d-plug goes to the stator wire? Is that right? If so, which stock kit would that be.

Thanks again man, I really appreciate it. And yes, I know I have to clean my t-stat housing, lol.

 

[seijirou]

Yes you just need to replace that factory D plug. If you cut back the harness on the factory one, you'll see that the stator wire actually loops back in the harness to plug back into the alternator. If you look on the voltage regulator, which is where the D plug plugs into. You'll see the 3 letters, A S I. S is the Stator, which is typically white with a black stripe. A is your hot wire, usually yellow with white. Somtimes it's orange. And I is your switched wire. It is in line with the charge indicator light, it also comes on hot with ignition. It is almost always green with red. This is the wire that was blue on the new D plug.

 

[Chowder Head]

Alright, now that I know what to do, what is the stock piece I need called? A stock D-plug? And hopefully lastly, where can I get this? Do I have to place an order online or is it common enough to have parts store carry them?

Thanks a ton man for all the info.

 

[seijirou]

Alright, now that I know what to do, what is the stock piece I need called? A stock D-plug? And hopefully lastly, where can I get this? Do I have to place an order online or is it common enough to have parts store carry them?

Thanks a ton man for all the info.

You actually gave a link to where you can buy one!

http://www.pa-performance.com/searc...d+Wire+Kits&rqSku=&rqPartNO=&rqDesc=&rqOrder=

It's the 2G/3G Replacement Regulator Plug for $10.25 which probably isn't a bad price.
Autozone also sells things like this, but I cannot say for sure that they do sell this regulator plug. Try also giving a Ford dealer a call and see what they can do.

 

[Chowder Head]

Well I'll be damned, lol.

Now that looks like exactly what I need but just a quick question. How would I obtain that plastic piece that fits on the stator? Could I just cut the one of the new wiring harness (the one that's in the pics) and splice that on the correct wire?

Again, thanks for the info man, I owe you one.