Do I need a new alternator?

[flash75]

You can run a car for an hour or more during daylight hours on a fully charged battery. To do that you must not use anything that consumes power but the engine. You can ruin an alternator by removing the positive battery terminal with the engine running. You could do that on old cars with a generator.

The corrosion on the battery terminals should be cleaned. Usually the alternator isn't charging when the battery light comes on. Most alternators are rebuildable, if it has been in a fire or major parts or broken it may not be rebuildable.

Clifton

 

[808MP5]

Also if your afraid of disconnecting the NEGATIVE terminal after starting the car you could also try a DMM. Hook it up to your battery terminals and start the car. If the voltage doesn't spike to 13-14.4volts your altenator isn't charging. And if you've done anything recently to your car make sure it's plugged in. I once forgot to plug mine in.

 

[i12drivemyMP5]

Also if your afraid of disconnecting the NEGATIVE terminal after starting the car you could also try a DMM. Hook it up to your battery terminals and start the car. If the voltage doesn't spike to 13-14.4volts your altenator isn't charging. And if you've done anything recently to your car make sure it's plugged in. I once forgot to plug mine in.

+2 on NEGATIVE cable & +2 on the volt meter.

 

[phishstik]

Wife was stuck in parking lot last night with low battery. Had a boost, car ran 4 more minutes. While running was barely testing at 12V, new alternator time! Thanks to i12drivemyMP5 for the steps on removing it , glad I didn't have to remove from below!

SDG, its a pain pulling it up by the engine and firewall but you'l figure it out. I found that turning it so the pulley is facing the front bumper, and pressing back tight against firewall was the way to go.

If only that damn big (air conditioning) line wasn't in the way.

BTW had to do this last night in my -10'C garage, helps encourage to do things faster!

 

[SDG]

Yeah I am changing mine out tomorrow. Gonna start in the morning cause I dont know how long it will take and it gets dark here at like 4:30pm now. Did it take a long time to do?

I got my car home and the thing died as I was pulling it into the driveway...battery lasted that long at least. Hopefully I didn't screw up my brand new battery by draining it so much.

Oh..about the belts..did you replace the belts during the repair? I have new belts I've had in my trunk just in case...should I switch them out while I have them off? You do have to take all the belts off right?

 

[sube]

Yeah I am changing mine out tomorrow. Gonna start in the morning cause I dont know how long it will take and it gets dark here at like 4:30pm now. Did it take a long time to do?

I got my car home and the thing died as I was pulling it into the driveway...battery lasted that long at least. Hopefully I didn't screw up my brand new battery by draining it so much.

Oh..about the belts..did you replace the belts during the repair? I have new belts I've had in my trunk just in case...should I switch them out while I have them off? You do have to take all the belts off right?

It is either a loose belt or more likely the alternator, when the belt is even slightly loose on an alternator it is under such a load it will squeal like hell.

IMHO a voltmeter is an invaluable gauge in a car, an alternator can be caharging enough to put the charge light out but not enough to keep the battery fully charged, a healthy alternator should show a charge rate of 14 volts when car is running.

Pat.

 

[SDG]

No, I dont have any squealing from the belts..I did before last year and changed them after they ripped off. Its the alternator this time. Actually a mechanic told me my alternator was bad like a year and a half ago- he never tested it and probably just wanted to charge me for labor...but I think this time its shot.

In any case I will be buying one today and putting it on tomorrow. The belts are tight and not squealing nor slipping so its gotta be the alternator.

 

[phishstik]

I was thinking of changing the belts, but realized I would have to take them both off and its too damn cold for me to bother doing that now!

Taking off alt and taking out battery, was about hour and half job. Main time sink is wedging damn alternator off the mount, and squeezing it up through the hoses/firewall.

Can't tell you how long it takes to reassemble cause my replacement alt is still being shipped...........

 

[SDG]

Yeah its cold here too but not that cold..like mid 30's at night..50's during the day. My belts have ripped off twice so I'm surprised the alternator has lasted as long as it has. I just hit 100k miles so my car is in dire need of maintenance.

If I get annoyed changing it tomorrow I will just think how cold u had it and shut my mouth..lol

 

[RockerPro5]

Since you said that there was lots of corrosion on the old battery, it seems that would be the reason for the battery light blinking now and then (due to the bad connection).

If I were you, I would get a simple digital voltmeter and measure the voltage (at battery terminals) after the car has sat overnight. It should be ~12V. Then start the car, and immediately go measure the voltage (at battery terminals) and see if the voltage increases to ~14V. If the voltage doesn't increase then it confirms a faulty alternator. This is an elaboration of sube's post.

With the issue of bulbs burning out, it could be due to a bad voltage regulator, to test this, you would measure the voltage while a helper rev's up the engine, and see how much change there is.

I hope this helps.

 

[SDG]

The battery light stayed on even after replacing the battery with a new one.

So I have everything disconnected, the alternator is free..but which way do I twist it to get it out the top? I didn't remove the the tension adjustment mount since I read that one guy did it without taking that off and I can't seem to get to the bolt that holds it on anyway.

Should I tie a rope to the alternator to help pull it up or something..I'm having a hell of a time trying to get it out the top...and my new years eve hangover isn't helping..lol

 

[phishstik]

You moved cruise control, and that cylinder on the firewall right? For the alternator I kept it down low, rotated so the pulley wheel was pointing to front of car then pressed the back right against firewall and squeezed it up, once your past that first part your good. Its just hard to get past that air conditioning line.

 

[SDG]

Yeah I moved that all out of the way. I just couldn't move the mounting bracket.

I will try your method in the morning and see if I can get it out. Is it a bit easier putting the new one in? I hope!

 

[P-Funk!]

Uh, bad news, kitten.

By totally draining the battery - you may have killed it. Can you put it on a real slow charge before just 'jumping it'?

 

[la2lvtom]

So changing the altenator really sucks, huh? When I got my high out-put altenator I went to the dealer to find out how much it would cost to install and they told me 4 hours at $85 an hour cause the axle has to be pulled and I was like yea right so me and a friend tried to do the change ourselves and after 3 hours of removing all kinds of things on top with no luck removing the alt we wound up pulling the axle and the stupid thing just dropped right out the bottom. It was probably only an hour and a half of time and a $10 jug of gear oil, we should have just done that from the start. Guess the dealer knows what they are talking about lol. Hope your experience went o.k. changing the alt sucks in this car.

 

[i12drivemyMP5]

So changing the altenator really sucks, huh? When I got my high out-put altenator I went to the dealer to find out how much it would cost to install and they told me 4 hours at $85 an hour cause the axle has to be pulled and I was like yea right so me and a friend tried to do the change ourselves and after 3 hours of removing all kinds of things on top with no luck removing the alt we wound up pulling the axle and the stupid thing just dropped right out the bottom. It was probably only an hour and a half of time and a $10 jug of gear oil, we should have just done that from the start. Guess the dealer knows what they are talking about lol. Hope your experience went o.k. changing the alt sucks in this car.

The oem will come out up top. Not sure about the hi output alt size so won't speak to that. On another note, you are the only one I've seen on here with the same rims as I have. Mine were already on the new car at the dealer which is why I chose that particular one. I did get some Motegi center caps since they are much beefier than the Ace ones. Also have rays blue valve stems & black lugs...................

 

[la2lvtom]

We tried and we tried but could not get that darn oem alt. through the top, luckily my friend is a mini trucker so he knew how to do all that mechanical junk so removing the axle was nothing for him. I see your Manta's are polished, mine are chrome (they look better with the laser blue paint) The Mantas are the only ones I could find with a 52mm offset so they would tuck in the rear with the lowering and not have to roll the inside lip on the fender. cool rims though, I get a lot of compliments on them.

 

[SDG]

Yeah I got it through the top by running a cable through the bracket hole and yanking on it till finally it popped out the top. Replacing the new one was pretty easy.

However...now my car idles REALLY high when I start it..like 2500-3k rpm's...then once it warms up it settles down.

Then tonight I was driving home and hit the cruise control button and my check engine light came on and is now stuck on..what the heck?

Maybe I need to loosen the alternator belt a bit to fix the idle..just a guess. No clue about the check engine light.

 

[SDG]

Update:

Now I am getting my battery light coming back on again! ARGH! It goes on and off...possible loose battery cable? Loose belt? Its not squealing or anything so it doesn't seem to be slipping. I am going to bring the car to autozone in the morning and have them check the codes, battery and alternator. I seriously hope its not a bad alternator they sold me..I don't feel like changing it out again!

 

[phishstik]

Perhaps the problem with cruise control is that tiny vacuum hose? Did you disconnect/reconnect it cause I almost forgot that one. Also check electrical harness on it.

Do you have a multimeter to check the voltage at the battery when running and when shut off?