Questions tagged [alternator]

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 provides the motion to produce power.

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14 votes
2 answers

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 ...
Robert S. Barnes's user avatar
6 votes
5 answers

What happens if I disconnect the battery while the car is running?

There are some comments on the question Are there any modern diesel engines that require electricity to continue running? suggesting that disconnecting the battery while the car is running can damage ...
James Jenkins's user avatar
9 votes
1 answer

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 a ...
Zaid's user avatar
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6 votes
4 answers

Technique to test an alternator - fact or fiction?

A friend explained that the following is a simple way to test an alternator to see if it is working: Turn on the vehicle. While it is running, carefully remove one of the 12V battery leads. See if ...
End Anti-Semitic Hate's user avatar
13 votes
4 answers

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 ...
Pēteris Caune's user avatar
7 votes
3 answers

Should an alternator ever run over 14.5V?

Bought a replacement alternator but I am sending it back as I measured and have seen it running over 16.5V. The manual says the regulator should keep it to a max of about 14.5V. I put a brand new and ...
user2800708's user avatar
4 votes
2 answers

Chevrolet Aveo won't start (codes: P0340, P2106, P2110, P2101)

Two months ago my Chevrolet Aveo 2007 had intermittent interior and exterior light flickering problem that was especially noticeable while idling or driving at low speeds. Also, one morning the car ...
user2138912's user avatar
11 votes
4 answers

how fast does the alternator charge the battery?

It would appear that the common word of wisdom is that car alternators provide 50A of output. I actually looked at the supposed specs for my 2008 Jetta 2.5L on the internet -- a compact car -- and it ...
cnst's user avatar
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10 votes
3 answers

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 ...
Zaid's user avatar
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8 votes
3 answers

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 ...
Simon East's user avatar
21 votes
4 answers

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?
End Anti-Semitic Hate's user avatar
8 votes
4 answers

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 ...
Nate's user avatar
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7 votes
3 answers

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 ...
Traver's user avatar
  • 73
6 votes
6 answers

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 ...
Kris's user avatar
  • 163
4 votes
1 answer

Why spraypaint a stator when refurbishing an alternator?

I went to a shop and picked up a "refurbished" alternator. I saw the work area and noticed that they seem to partially spray paint the stators on their refurbished alternators. Mainly the main body ...
Robert S. Barnes's user avatar
4 votes
2 answers

diagnose faulty voltage regulator causing battery overcharging?

I've been having an issue with an '03 Toyota Echo. The alternator died (at least that is what I thought) as the battery kept going flat. I found an alternator at a wrecker and fitted it, and I ...
Tim's user avatar
  • 465
3 votes
1 answer

Why won't my car even crank?

While inspecting the wires under the hood of my 1995 Camry LE (v6) I noticed that a wire ending at my alternator was loose. Note that before I disconnected anything, my car would start fine... So I ...
Nathaniel Davidson's user avatar
2 votes
3 answers

Rover 25 - My battery light starts flickering on/off on the dashboard

My girlfriend noticed this yesterday and thought it was odd, it stopped but started happening again this morning on my way to work, I think its a V plate.... "as I’m driving along my battery light ...
Paul C's user avatar
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2 votes
3 answers

Are inverters bad for your car?

I bought a Duralast 130W inverter and it says 260 peak watts and it plugs into the 12V cigarette lighter. I want to charge my HP laptop with it. Is it bad for the car?
Edward's user avatar
  • 169
2 votes
2 answers

when trying to start my pajero it just clicks and wont fire up

pajero wouldnt start and just clicks had aa out and they said it was the alternator but tried car over weekend and it started first time. tried this morning and just click had to have a jump start to ...
user6289's user avatar
1 vote
2 answers

How likely it is that low alternator voltage cause Xenon HID headlamps ballast to fail?

It seems that the alternator is producing a bit low voltage, about 13.4V max, while this should be over 14V AFAIK, undercharing the battery. The left Xenon HID headlamp ballast failed some time ago, ...
lowtoxin's user avatar
  • 121
1 vote
2 answers

Device that prevents vehicle from draining accessory batteries?

Not exactly sure if the device / component or setup I'm asking about even exists. But, here is my naive question (I am bad with electrical in general): Is there something built into modern vehicle ...
maplemale's user avatar
  • 541
0 votes
1 answer

Little/no charging but alternator and battery test good

For the past few months, and seemingly getting progressively worse, I've had a charging problem: both battery and alternator test good (checked via charger with alternator test mode and higher-end ...
R.. GitHub STOP HELPING ICE's user avatar