Battery? Alternator? or what??

[Jason94sport]

Leaving work, I come out start the X & the voltage gauge is at almost 8 & my battery light is on. I thought it was the battery. I have an Optima. I take it to the auto store. Their tester says it's good. I install it back into my X start it up again the same thing. I drive around the corner & the voltage gauge & battery light turn off. All is normal......Then it turns back on. Does this 2 more times. Now it's back to on & staying there.
I don't have any way to test it now It's dark out anyway. I'll take it to my shop tommorow.

However what do you guys think it is? The alternator or the regulator on the alt?
The cables are tight, no corrision.
Battery seem to be good.
It's out of the blue I haven't had any starting or electrical problems & I have high loads(lights, siren, stereo, AC etc)
I have a 200 amp alternator I got used from a member here. He said he used it a year. I have had the Alt & battery ironically a year to the day. 6/14/05

 

[skatermania88]

Do you think you have a short somewhere?




That's weird man. My truck did that but, it was for an obvious reason. I put a battery in that was too big and it wouldn't tighten down, I went wheelin and got back on the road. My stereo kept cutting off so I stopped and looked under the hood. The battery was being held by the + terminal, and it was leaning down towards the belts, with the negative terminal disconnected. Yep but if your problem would have been as obvious as mine you would have known.

 

[Blee1099]

Get the alternator tested don't forget even though the cables look good in appearance, that can be a misconception. 91-94 Explorer battery cables are known to corrode from internally.

 

[Jason94sport]

Yes I know, but mine are good for sure.

 

[prerunner02]

get a new alternator

i have a mustang that did the same this and if i went and banged on it with a screwdriver handle the volts jumped back up and the batt light went out. that worked 4 or 5 times till i just replaced it no problems since

 

[1IronMike]

I would suspect the alternator also. You should be able to get the bursh kit and make it better.

 

[Turdle]

12-13 volts off
13.5-14.5 volts engine running. measur across battery terminals
If you do not have the higher voltage with engine running, the alternator is not functioning correctly.
If you do, then switch the meter to read ac volts. If it is over 6 v ac, there is a bad rectifier.

 

[ma96782]

The battery can be bench tested and so can the alternator, usually for free.......take them out and down to your favorite auto parts store.

Next would be a "short" or "broken wire" much harder to track down.....good luck.

Aloha, Mark

 

[Jason94sport]

The battery is fine it's been tested. The Alt is out(I'm getting good, 7 minutes) It will be tested later today.

 

[Jason94sport]

The Alt was tested & is working fine. The shop suggested it may be a belt slipping problem. They noticed black belt residue on the alternator. They say it may be the belt, tensionor, or another pully locking up.
Does that sound reasonable?

For the last 6 months I have gotten a LOUD high pitched squeal from the engine 3 times. It happend when I gave the X gas, & then faded away. Didn't think much of it cause it happned 3 times in 6 months.

The tensionor was replaced 2 years ago.
The belt 4 months ago.

I reinstalled the alternator. Still have the same problem. I checked the belt & the tensionor & they seem fine. There's no slop in the belt & no noises. The rest of the pullies spin freely. I have to bring it to the shop to have them test everything in the X. Maybe there's a short somewhere. That's all I can think of.

 

[ExploderHOKIE]

I work at Advance auto, so i deal with a ot of dead batteries, alternators and stuff like that, from what your saying sounds liek an alterantor to me, iof there is an advance near you get them to test the charging system while the alternator is still on the car, it might give you a different answer, also, since it kind of going in and out, it might be the voltage regulator, but that part of the alternator, so you might have to replace it anyway

 

[BrooklynBay]

Did you test your wiring with a continuity tester? If you have a break in one of the wires, you will get these intermittent no charge situations. Make sure that your battery terminals have no corrosion, and that all ground connections are tight, and rust free.

 

[Blrob]

Check the connectors and wiring going intoo the alternator. I've been having the same problem with mine. If you wiggle the wires around, the battery gauge will go back up. You may have a lose connection going to the contacts to the alternator.

 

[Jason94sport]

Yeah testing things in the X is next. I don't see any rust or corrsion. I live in FL I don't get that. The cables all look fine & feel fine. Nothing is loose. It was a sudden thing. I never had any problem before & I drove 250 miles last weekend in 1 day.
That's why this is very strange to me.

 

[Gatorblazer]

Heres a weird one. I had a similar problem in a 93 ranger. Eventually the alternator stopped charging the battery, causing the truck to die. Replaced the alternator, did the same thing. Turned out that it was bare wire in the main harness causing a short. No other symptoms other than no charge. Check your wires just to make sure.

 

[j602]

It's the alternator. I would put money on it.

 

[Papa]

The Alt was tested & is working fine. The shop suggested it may be a belt slipping problem. They noticed black belt residue on the alternator. They say it may be the belt, tensionor, or another pully locking up.
Does that sound reasonable?

For the last 6 months I have gotten a LOUD high pitched squeal from the engine 3 times. It happend when I gave the X gas, & then faded away. Didn't think much of it cause it happned 3 times in 6 months.

The tensionor was replaced 2 years ago.
The belt 4 months ago.

I reinstalled the alternator. Still have the same problem. I checked the belt & the tensionor & they seem fine. There's no slop in the belt & no noises. The rest of the pullies spin freely. I have to bring it to the shop to have them test everything in the X. Maybe there's a short somewhere. That's all I can think of.

The battery and alternator have tested sat correct.
You have belt dust and a loud squeel-follow this lead and the verified symptoms they represent. A bad bearing can load the belt till the alternator speed drops below the critical 900 RPM (see Aldives posts on under and over drive pullies).

 

[Jason94sport]

See I don't have a loud squeal. Only happend the 3 times in a 6 month period( i have no idea what it was or where it was coming from it lasted only a few seconds) & it's been silent through this problem. I don't see the belt slipping. I looked & felt the alt pully with a screwdriver & it's spining. The alt shop tested it on a machine that loads the pully as if it was in the car & then reads the voltage at ilde up to 4000RPM. It tests fine.
The problem is not effected by RPM.

 

[Jason94sport]

Ok fine.........It's the alternator.
I ran the tests my factory 94 service manaul says. It's either a regulator problem, or the insides of the alternator.
I had battery voltage = to the battey at the battery terminal, the A terminal, but only 2.3 volts at the F terminal. It's supposed to be = to battery voltage.
I bought an alternator & did the same tests & all 3 points were correct. I installed that one & it ran fine. I took it out & returned it.
I gave mine to the alternator shop to fix it. I'm sure it will be less then the cost of a new 220amp.
Now why their tests before said it was ok is another issue. (it was a free thing so maybe they just half assed it)

 

[Jason94sport]

Finally got it back. The shop replaced the "rotor" I don't know what that is??
Seems to work now. I do have a little noise from the alternator now though. I may just buy a new 220amp & have this for a spare.