An engine accessory which generates alternating current (AC). The electricity is then fed through diodes which converts it from AC to direct current (DC), which is usable by the automobile in general. The alternator is usually driven by belts which are connected to the crankshaft of the engine which ...

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13
votes
4answers
318 views

Can a weak battery destroy an alternator?

I've heard a story that a weak vehicle battery can destroy an alternator or cause an alternator to fail early. Is this true, or is it largely fiction?
13
votes
1answer
128 views

How to determine exactly what's wrong with my alternator?

My 98 Mazda 626 GF 2L uses an 80 amp fp34 A2TB0191 alternator with an internal voltage regulator. I did a little test where it I turned on the bright lights, AC, radio, rear defogger and opened the ...
11
votes
3answers
2k views

Why can't alternators provide full current at idle?

I was reading about load testing and full fielding alternators in a few different books I've got, and one of the points they all made was that to test an alternator's maximum output (or close to it) ...
10
votes
6answers
1k views

Can a car AC unit be run on just the car battery?

This might be a silly question but I was wondering if a car AC unit be run off entirely on battery or alternator? As this could help in Preventing power loss during important times such as ...
10
votes
3answers
315 views

Is any power from the alternator 'free'?

Cars generally (and specifically a Honda Accord 2002) are not very energy-efficient. Given all the inefficiencies, is it "free" to plug in, say, a smartphone into a car to charge while I am driving? ...
10
votes
2answers
1k views

Can I safely upgrade to an AGM battery?

AGM batteries are capable of being charged at a faster rate, and may draw additional amperage from the alternator if it is not regulated. Many cars that come with AGM batteries have special charge ...
9
votes
6answers
10k views

Noise in stereo that changes pitch with engine RPM

This is a question of curiosity. I have a '98 Acura Integra, a cheap car stereo with a 3.5mm aux in, a cheap inverter and a smart phone. If I have the smart phone audio hooked up to the car stereo and ...
9
votes
2answers
534 views

Non-functional gas pedal, engine stalling, dead battery: broken alternator?

I have a 2005 Nissan Sentra. The following happened twice within a few days: I stopped at a red light. When the light turned green, pressing the gas pedal had no effect at all. However, the car ...
9
votes
4answers
9k views

How to assess battery charge level and alternator performance?

What diagnostics can be done to to assess battery charge level? I'm interested both in one-off tests like can be done in car service and also continuous monitoring during normal use. Car panels ...
8
votes
1answer
74 views

Connecting to the Battery During Emissions Testing to Measure RPMs?

When doing emissions testing, they connect to the battery, either directly, or using the cigarette lighter socket. I'm assuming that this is to measure the RPMs, as the only other thing connected ...
7
votes
4answers
43k views

How to diagnose a starter motor that does not work

My e46 M3 would not start when I got to the parking garage after work. When I first turned the key, I heard a sound like grinding gears, but I was so startled that I immediately stopped trying to ...
7
votes
2answers
6k views

Can an engine stop from a bad battery?

The car is a 2005 Toyota Corolla CE. Its engine is the 1ZZ-FE, a 1.8L straight four that runs on gas, not diesel. The alternator is stock, and tests out just fine on the multimeter in both voltage ...
7
votes
1answer
842 views

DIY Alternator Belt Tensioner

I've got a diesel engine in my boat, but the previous owner had somehow snapped the alternator bracket, and fitted it fixed to the boat rather than the engine. Now the alternator doesn't move when the ...
7
votes
2answers
116 views

Battery and Alternator Pass Test - 2003 Mustang GT

I have a 2003 Ford Mustang GT, I had the battery tested and it will take a jump and start up so naturally I am thinking the alternator is bad. I take the alternator out and have it tested 3 times and ...
7
votes
3answers
3k views

Does idle RPM increase when there is heavy load on the electrical system?

I am thinking about installing a 500w halogen (HDX brand) on the roll bar in my jeep as the dome light because often I work in the back when it is dark or when I would like more light. The 500w light ...
7
votes
2answers
634 views

How to detect a failing car alternator..?

Is there some way we can predict that the car alternator is about to fail in order to avoid a discharged battery situation on the road.. Although it will slow the sound of horn and will dim the ...
7
votes
2answers
60 views

Semi-permanent power inverter

I'd like to install a semi-permanent 500 watt inverter connected to the car battery for greater power delivery. The battery is in the passenger area, so there's no need to run wiring through the ...
7
votes
3answers
549 views

Kawasaki EX650 - What causes a stator to burn out?

My motorcycle recently required a new stator (plus a new regulator rectifier and battery) because the stator burnt out and fried everything. What are the typical causes of a burnt-out stator? Does ...
7
votes
3answers
10k views

How can I clean the dirt build-up in my alternator?

The alternator in my '04 Lumina SS is its Achilles' heel. It lasts a few years before it starts to overcharge the battery, after which the only practical remedy is to replace it. While I cannot be ...
7
votes
2answers
63 views

Multimeter Voltage doesn't match ECU Voltage

I was messing around with electrical loads on my 98 Mazda 626 GF 2L today and noticed that the voltage I was reading at the battery with my multimeter, didn't match the voltage the ECU was report via ...
7
votes
1answer
172 views

Battery light on after new alternator

Car: 2003 Honda Civic Si G1Wh dash cam, 400w amp, 4300k HIDs My alternator failed badly (stereo cutting off), no battery light. Replaced it with a reman Duralast, battery light is on. It shows 14.5v ...
7
votes
2answers
220 views

Alternator vs Battery

I hadn't used my car in a week. Normally it always starts. Then one day after one week it didn't start. I got a jump from my neighbor and i was able to drive around for more than 20 minutes. I stopped ...
7
votes
1answer
2k views

Why would turning on the A/C affect my alternator output voltage?

So yet another chapter unfolds in the A/C gremlin saga of my LS1 Chevy. Backdrop A/C compressor is relatively new (2 years old) One of the belts is squeaking (not sure which one) Recently performed ...
7
votes
2answers
48 views

How To Remove The Alternator From A 1998 Toyota Corolla 1.3 4E-FE Engine?

I need to remove the alternator from a 1.3 4E-FE engine in a 1998 Toyota Corolla, but have ran out of ideas to do it. This is the photo of the alternator in situ: To the right of the alternator is ...
7
votes
1answer
94 views

Alternator isn't charging battery properly. Replace or swap regulator only?

I have a 2015 Honda Fit EX. On my dashboard, there is a small screen that has been displaying "CHECK CHARGE SYSTEM" and displaying warning lights (TPMS, power steering, and stability control). I ...
7
votes
2answers
68 views

Can long term parking affect alternator?

My neighbor just told me that his mechanic informed him that leaving a car parked long term not only effects the battery, but can also deteriorate the alternator. The battery having issues makes ...
7
votes
2answers
14k views

Failing alternator, idler pulley, or something else?

I have 1997 Chevrolet Lumina sedan. I’m trying to diagnose a sound coming from my engine. It is a “whirring” noise that varies with the engine speed (e.g., if I accelerate, the sound becomes louder ...
6
votes
9answers
3k views

2 Volts on Car Battery

My car battery has gone completely flat after leaving my car parked up for about a month. Tried turning over the car today, and none of the lights on the dash light up. Ran a multimeter across the ...
6
votes
3answers
902 views

Will an auxiliary battery hurt a vehicle's alternator?

I am going to be road tripping and living out of my SUV for a while. I need a way to power a tiny portable cooler/fridge 24/7 and would like to be able to power my cell phone, laptop, and maybe a few ...
6
votes
2answers
45 views

Does Coil rewinding have a negative impact with the existing system?

I have a question towards the rewinding of a coil. Here is the tech spec of the bike:- Battery : 9 Ah, 12 V Generator : 12V, 100 W Fuse: 12V 10A My bike comes with an electrical spec of DC (...
6
votes
1answer
80 views

Alternator whines when it's cold, 2000 Toyota Camry (5S-FE engine)

I have a 2000 Toyota Camry with the L4 5S-FE engine. The car has 140k miles on it. When I first start it, the alternator whines fairly loudly. I narrowed it down by ear, then used the typical ...
6
votes
1answer
93 views

Alternator grinding - Is it OK to drive to mechanics?

I have a 2000 Suburban and the alternator is making a grinding sound. The Suburban still starts up and I am wondering if it could harm other engine components (like the serpentine belt) trying to ...
6
votes
1answer
464 views

Alternator, Battery, or Fluke?

While we were out running errands yesterday, our car failed to start after a half hour stop at one of our destinations. The first attempt to start the car resulted in nothing but a rapid clicking ...
6
votes
0answers
52 views

VW Transporter T5 - p1503 Generator Terminal DF (Load signal) Signal Improbable

I have a VW Transporter T5 2007 with 2.5 TDi BNZ engine. I have the following fault code (among many): p1503 Generator Terminal DF (Load signal) Signal Improbable. This fault code gets repeated ...
6
votes
3answers
498 views

Alternator draining battery

My alternator has been draining my battery in my Datsun 240z since I swapped the engine (VQ35). It takes around 4 days to drain the battery to the point I can't start it. It charges it fine when the ...
5
votes
1answer
101 views

What are slip rings with respect to a cars alternator?

This is not a physics forum, and as such I don't expect answers to explain Faraday's law of induced emf (electromotive force), which is the basic physics principle behind how an alternator is able to ...
5
votes
3answers
259 views

Causes of Premature Alternator Failure

I bought my car brand-new a few years ago, with only 50 miles on it when it came off the lot. It's perfectly stock - no modifications made, though some parts have been replaced for repair purposes. ...
5
votes
1answer
59 views

2002 golf dead battery - Was able to jump - Bad alternator or Battery

I have a 2002 Golf. I put the car on the drive on Friday night and tried to use it on Wednesday and it was dead. No lights, no display nothing. I came home and jump started and it ran fine. No stalls ...
5
votes
1answer
58 views

Why would my Toyota Corolla die soon after starting it?

I have a 1996 Toyota Corolla DX with about 200k miles on it. It runs good for the most part, but recently had a problem where it would not start. Napa tested my alternator, which failed, so I ...
5
votes
1answer
174 views

Burning Rubber while driving and after

Tonight I popped out in my partners car and noticed an awful burning/chemical smell whilst driving, this smell got worse if you turned on the AC (FAN BLOWER), so I got her to pull over and had her pop ...
5
votes
2answers
66 views

Jeep electrical/charging problem

I have an electrical problem with my 96 Jeep Grand Cherokee. The alternator whines and the battery gauge drops to zero. I put a new battery in and a new alternator and it didn't fix the problem. any ...
5
votes
3answers
653 views

93 Nissan Sentra SE-R, replaced alternator voltage still low

My car died while I was driving it, but I can put the battery on a charger (or from another car, with jumper cables) and get it running albeit for a short period of time. I put a multimeter on the ...
5
votes
1answer
62 views

ECM Fuse Blown what to test next

Recently I was on the highway and suddenly my car broke down and it was cranking and all but not starting so I knew some fuse has blown. I removed the indicator fuse and used it for fuse which gave ...
5
votes
1answer
1k views

Can a bad battery damage voltage regulator?

I have a '91 Ford Sierra Saphire 2.0 OHC (pinto). Have been struggling with having no charge for weeks now. I've tried two different alternators, had one of them completely rebuilt by a professional, ...
5
votes
1answer
36 views

My car Diesel Yaris doesn't start very well after an alternator change?

I have recently changed the alternator after it died in my diesel yaris. I have done about 150 miles with the new alternator however it still doesn't start very well. It now takes 1 long or sometimes ...
4
votes
4answers
237 views

How to replace Alternator out (2001 Nissan Sentra) [pictures inside]

I am trying to remove the Alternator on my Nissan Sentra 2001. I believe I need to take the alternator belt off. It's tightly on the pulley - see picture How to make the belt loose? I am told that ...
4
votes
3answers
480 views

Engine Mounts issue can be caused by replacing Alternator?

My mechanic recently replaced the alternator on my 2007 Toyota Camry. When he returned the car to me he said that my motor mounts need to be replaced. Now I notice a vibration at idle. I am not a ...
4
votes
1answer
52 views

one wire alternator

I have a one wire alternator on 350 Chevy V8 in a 57 Belair. After charging the battery and running the car for about an hour the battery will run down. Changed the alternator but no difference. ...
4
votes
3answers
1k views

Is it safe to charge two batteries off of one alternator?

Right now I have a 3000 Watt invertor wired to a 100ah sealed deep cell battery that I trickle charge at night. My plan is to run #6 wire from the battery in the engine to the spare battery so the ...
4
votes
2answers
10k views

Mustang charging system warning light on, but battery and alternator both passed testing?

I have a Mustang that the battery light stays on. I changed the battery and the alternator was checked by Autozone, they said it was good. I need help