[phnx]

Alternator Charging Battery @ 17volts? - SOLVED

The vehicle is currently running fine however this concerns me. My friends believe that this is very abnormal and may have something to do with the alternator.

With the engine running, a multimeter reading off of the battery POSTS is putting out 17.2-17.5volts. As I understand it, this should only be reading around 14volts when the engine is on. When the car is off and has been sitting for a little while, it will go back down to 12volts buts not under 12.0.

Has anybody else seen anything like this before?

 

[Grumpy]

I had this occur on a VW many years ago. The voltage regulator has failed and unfortunately it is built into the alternator and I'm pretty sure it requires a replacement new or rebuilt alternator.

 

[bluefront]

Your alternator is failing. 17V is at least 3V over specs..... Eventually you are likely to have other problems, like burned bulbs, a failed battery, or worse. Not too much can be done other than replacement, since the regulator is internal. Few places repair such problems any longer.

With the engine off, the battery voltage should test around 12v after it sits a while and the surface charge drains off......that's normal.

 

[jffry5959]

definatly time for a new alternator as posted previously the regulator is toasted, keep in mind if you are running some serious stereo equipment you may consider a higher amperage output alternator to save some of the wear and tear on a stock alternator

 

[jffry5959]

definatly time for a new alternator as posted previously the regulator is toasted, keep in mind if you are running some serious stereo equipment you may consider a higher amperage output alternator to save some of the wear and tear on a stock alternator

 

[elpibe7777]

It does sound like your regulator is bad. If you can, take it off and carry it into a parts store. They can bench test it for you. If you want to make sure. Autozone has a decent test machine, I just would not recommend buying the alternator from them. You can also call Mike at Hillbish Ford and he can give you a price on an OEM alternator. C-F-M sells alternators with a higher amperage. LINK

 

[TnFocus]

Def bad regulator. I had this happen on my truck. The dash lights got very bright, and I wasn't able to shut them off in time. Both head lights blew, turn signal, and brake lights.

 

[viney266]

Just as everyone has said above, time to pull the alt. It IS a bad regulator and needs fixxed ASAP, I am amazed at 17.4 you haven't lost the lights yet. It will blow all the lights right around that voltage, get her fixxed.

 

[phnx]

Extremely reassuring to hear everyone saying the same thing! Thanks for your help guys, I'm working on getting it swapped out over the next day or two!

 

[besthaticouldo]

good luck...its not a fun swap.

i found it really easy to put a jack with a piece of wood on the bottom of the motor and pull the passenger side motor mount.

i got it down to a 40 minute job, from start to finish.

 

[PumkinSvt]

^ derrick PM on how you took out the alternator!

I have to do that this weekend.

 

[besthaticouldo]

dude...its simple.

2 bolts, take the passenger side motor mount off...rotate the motor forward and wiggle it out through the top.

its really easy.

make sure all the connections are off tho.

 

[PumkinSvt]

I duno it doesnt look easy! looks like a bitch to me, but wth I am up for a challenge

 

[phnx]

Well, having never done it before, I'll report back after this weekend on how much it sucked!

 

[viney266]

Remove the powersteering and radiator resevoirs, leave "em hooked up to their hoses, just move them out of the way. I did mine in 45 minutes without removing the motor mount, but its a tight squeeze and you need to bend the one mount for the bottle out of the way. I can see that the motor mount removal would give you more room. Its not really that bad.

 

[NatDogg]

Not bad?!

Let me tell you about the first time I took the alternator out of my Zetec [rant]:

First off, I had never done this before so I looked up as many instruction sets as I could and followed the shop manual to a T. They all said the same thing: "it's a tight squeeze". Removing the alternator bolts is simple. Removing the alternator is not.

Not once did any of the shop manuals accurately describe the difficulty of lifting the alternator out of the engine. Talk about squeezing a square peg through a round hole. "It's a tight squeeze" does not do it justice at all. I tried every orientation possible and just could not get the alternator past the engine. I even pushed the alternator down below the engine thinking I could remove it from the bottom. Nope. Blocked by the drive axle.

In an effort to prove to myself that I wasn't crazy and that all the instructions were lying to me, I attempted to push the new alternator through the same hole from the top while my old alternator was still below the engine. Big mistake. The new alternator slid right in. I couldn't believe it. I was stunned. By this time three hours had passed, my face and clothes were covered in grease, my hands were marred by dozens of cuts and scrapes, and I was about ready to kill myself. And now I had double the number of alternators to remove.

Eventually I got them both out and the new one installed (two hours later). Two years later the bearing on it failed. I had to replace it again (it was an Autozone alternator and they thankfully honored the lifetime warranty even though their alternators are terrible). Knowing the exact orientation that facilitates removal, I finished the job in only an hour or two.

Take it from someone who's done the job twice: you might want to consider removing the passenger side motor mount and rocking the engine forward. It's not at all easy to maneuver it out through the top otherwise. It can be done, but its not at all easy.

 

[big_daddy]

Remove the powersteering and radiator resevoirs, leave "em hooked up to their hoses, just move them out of the way. I did mine in 45 minutes without removing the motor mount, but its a tight squeeze and you need to bend the one mount for the bottle out of the way. I can see that the motor mount removal would give you more room. Its not really that bad.

Exactally! It took me 36 min (the second time) doing it this very way. I picked up mine from Autozone for about $180. I tried a junk yark alt first and it was also bad (trying to save a few bucks).

 

[whynotthinkwhynot]

I'd check the yellow pages to see how close the nearest rebuild shop is. I had issues with my parts store replacements for the van, finally took it to a local rebuilder. I never had a problem after that. They had a warranty, and were also able to upgrade the stock alternator for me.

With a situation like yours- it would be a lot cheaper. They can swap out the regulator for a lot less than you can buy an alternator.

I also agree that you're very lucky you haven't fried anything yet. I'd actually think the PCM and other computer components would be what I'd be most worried about.

 

[djmontara]

haha wow.. i didnt know they have the yellow pages in the US too.... my bad hahahaa (yer im so ignorant..)

 

[phnx]

Update! - I purchased a NEW 130amp alternator from c-f-m off of elpibe7777's suggestion (planning on heavy audio upgrades soon).

I just got done going through the chilton's book on changing them out. Thanks NatDogg for your personal account. I'm planning on doing this one to the book. I've got access to a fully stocked auto shop bay for $2/hour (military base) to do the whole thing. Will report back on Saturday!

As for fried components... I stopped driving the car as soon as I saw all the thread posts on how much damage 17volts can do. The only thing I noticed after the voltage regulator went out is the heater smells like rotten hell. Other than that, everything seems perfectly fine from an electrical standpoint. Headlights, blinkers, dashboard lights, stereo, everything seems to be working just fine.

Can't thank everyone enough for all your help! This being my first experience on the forum... I'm here to stay.