Questions tagged [electrical]

Concerning the main electrical system of a motor vehicle or internal combustion engine. Consider using [tag:electronics] for radios and other such systems. Use [tag:electric-vehicle] for questions about electrical powered vehicles and their unique systems.

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23
votes
4answers
12k views

How do I test my car battery?

My car still starts fine but when I turn off the car (just the motor . . the key is still in and "on") I noticed the headlights dim to almost off. It's and older car and the headlights don't turn off ...
14
votes
1answer
71k views

Do I have to rely on wire color to correctly wire up an O2 sensor?

It seems that everyone and their grandmother has a different color-code convention for 4-wire O2 sensors, which complicates matters when one is trying to wire up a replacement "universal" O2 sensor. ...
15
votes
3answers
1k views

Multimeter - Basic Functionality and Howto

Multimeters I'm looking for some responses regarding multimeter basics for the site tag-wiki to point OP's at when we want them to use one. The question is; What are the basic functions of a ...
21
votes
9answers
92k views

Battery drains by itself when vehicle is parked (parasitic draw)

A 1998 Jeep Grand Cherokee has gone through 3 batteries in the last 3 months. While they have all been replaced by warranties, it'd be nice to get the problem solved permanently. I've tested the ...
41
votes
3answers
20k views

Jump starting a dead battery: Connect black wire to negative pole of battery or grounded metal?

Most of the advice I've seen for jump starting cars instructs to connect the black wire to a bare piece of metal on the car with the dead battery. However, I've always just hooked up both poles to the ...
14
votes
2answers
2k 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 ...
10
votes
1answer
2k views

A most intriguing cold-start misfire mystery

I'm trying to help a friend out with a CEL on his 2009 Merc GLK 280. Hooked it up to an OBD2 reader and retrieved a single code: P0300 - 'Random/Multiple Cylinder Misfire Detected', via the 'OBD ...
14
votes
5answers
841 views

How do you test analogue electrical circuits?

When trying to diagnose problems with conventional analogue electrical circuits, such as lights, speakers, heated rear windows, etc, as well as short-circuits and unexplained current draws, it can be ...
11
votes
4answers
25k 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 ...
6
votes
2answers
2k views

Writing CAN Messages

I want to know what should I write with the CAN ID to send it to ECU. I am using ELM327 and Raspberry Pi with all connections to OBD-II. Initially for sending general PIDs to the ECU through ELM327 ...
21
votes
4answers
5k views

Replace car batteries with capacitors?

I recently watched this video on YouTube which basically shows the guy replacing a larger capacitors with some smaller capacitors which he had bought. The larger capacitors were actually in place of a ...
7
votes
3answers
130k views

Low beam headlights don't work, High beam headlights do

The vehicle is a 2003 Chevrolet Trailblazer. The low beams aren't working. High beams are. The fuse is perfectly fine (tested and swapped out). The bulbs are fine too. A mechanic told me it could be ...
8
votes
2answers
9k views

Battery Light Won't Go Off Since Changing Battery

I just changed the battery on my 98 Mazda 626 and now the battery light comes on and stays on after starting the car. I checked the battery and it's reading 12.8v with the engine off, and 13.8 with ...
7
votes
2answers
5k views

Suzuki GSXR600 (K7) - Burned regulator/rectifier

I have managed to completely fry the regulator/rectifier on my Suzuki GSXR600 (K7). I suspect that it happened when I blindly splashed into a big water pond, some water probably got on the connector....
6
votes
3answers
965 views

Upgrade to HID lights in a Jeep Wrangler

I would like to upgrade to HID lights in my 2008 Jeep Wrangler. The stock lights aren't bright at all. My question is, since this would be an aftermarket upgrade, what am I looking at here? Is it ...
4
votes
3answers
20k views

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 ...
28
votes
6answers
440k views

What causes battery terminal corrosion?

I put a new battery in my car about 8 months ago. After a problem starting a couple days ago, I found that there was massive corrosion under the battery terminals, so I cleaned them out and ...
19
votes
6answers
25k views

Adding a additional battery to car

I have purchased a brand new Toyota Innova. I need to install a a mac mini, 2 laptops and make this car a mobile office. I need to know if I can install another car battery in parallel, and will ...
4
votes
3answers
3k views

Clicking sound when trying to start

We haven't driven this car much in the last month, so it's been sitting in our back yard. Yesterday we tried to start it up, but it is making a clicking sound while turning the key in the ignition, ...
12
votes
6answers
58k views

What are the tradeoffs for positive vs. negative ground?

I just got a classic Ford 8N tractor running again. Someone trying to be helpful flipped the battery around, connecting negative to ground. This made the engine crank backwards! So I had spark, ...
8
votes
2answers
2k views

What Could Cause Flash Over / Arcing to Reappear on New Plugs?

I had been having some hesitation problems on my 98 Mazda 626 which after a great deal of research seemed to be solved by replacing the plugs: As you can see, there seems to be signs of flash over / ...
7
votes
4answers
5k views

Are there any (legal) ways to increase halogen headlight brightness?

My 2003 Opel Agila has H4 combined full and dipped beam headlight bulbs which are completely useless in the dark. It is really hard to see anything on the dipped beam. They do not seem to be very ...
6
votes
2answers
4k views

Is this the correct procedure for a stator test?

Stator Test I have a 2007 DL 1000 V-Strom: I followed the following process while checking the stator: Put multimeter to VAC Tested the three phases of the stator connector plugged into a new ...
4
votes
0answers
126 views

Negative surface charge?

At about 20°C, there has been a situation that the OEM battery in my '08 Jetta was not capable of starting the car at all (virtually no movement of the starter at all), after being used for at ...
3
votes
2answers
780 views

1987 Yamaha FZ700 headlights not working

I recently bought a 1987 Yamaha fz700, and the owner said the headlights didn't work, and I can't figure out what's wrong. We checked some of the wiring out, and the bulb connectors have no power ...
2
votes
1answer
843 views

'99 Audi A4 seat belt warning sign

I've had this seat belt warning light on my dash for a few weeks now. My dealer says the wiring to my driver seat is gone and replacing it could cost close to 800 USD. Is there a better option?
2
votes
3answers
69k views

Low beam headlights out, High beam working

The patient is a 1996 Chevrolet Caprice with dual-filament bulbs. Both filaments in both bulbs light up in high beam mode, but no filament on either bulb lights up in low beam mode. What could be ...
0
votes
0answers
24 views

Can i master reset or fix my android radio?

My android radio is'nt working right. Its coming on but not letting me go on any programmes and the radio signal is'nt staying on the chanel i ask for. I want to do a master reset how do i so it. Is ...
9
votes
1answer
1k views

Is it possible to repair an intermittent or flaky turn signal flasher relay?

Ouch, a new turn signal flasher relay is $65 at the local parts shop. Is it possible to DIY a repair of such a flasher relay?
8
votes
1answer
11k views

How to track down an intermittent battery drain?

I know there are several questions on here about finding the source of a battery drain (like Battery drains by itself when vehicle is parked (parasitic draw) ). However I don't think the answers ...
8
votes
1answer
2k views

Are all drive-by-wire cars completely (brakes, clutch, gas, steer) by wire?

I've recently purchases a manual transmission 1.5 Honda Mobilio. Which claimed to be a drive by wire vehicle and I assume it really is (don't know how to tell if a car is drive by wire). I am a new ...
8
votes
4answers
8k 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 ...
7
votes
4answers
8k views

Should only the left “Rear Fog Light” actually light up in a pair?

On a 2003 Saab 9-5 Aero, only the left rear fog light lights up. The right side has a bulb but when I switch the bulbs, the left still is the only side that lights up. I thought it might be a wiring ...
6
votes
1answer
266 views

Is it necessary to have the good car's engine running when jumpstarting

When jump-starting a vehicle, one first connects the positive and negative terminals between the two cars: positive to positive and negative (good battery) to a bolt head on the vehicle with the dead ...
5
votes
4answers
60k views

How do I know when a car battery was produced?

I have a hard time finding when my car battery was produced - can't find any defintive information. The battery is Bosch Silver with the following data printed: 5EN in huge letters and two rows of ...
5
votes
3answers
7k views

Start a circuit or device when you insert key in car ignition

I want to start a circuit in my car when I insert my key in car ignition and let it turn off when the key gets removed. I have Honda Civic 2007. Can someone just help me out as to from where do I take ...
4
votes
2answers
9k views

1999 gsxr 600 - What is wrong when my regulator keeps burning out? [duplicate]

I recently had my clutch replaced and a new battery put in. Within a month my regulator/rectifier burnt out of it. So, I purchased a new one. After 2 weeks that one burned out also. I replaced the ...
22
votes
4answers
2k views

Are there requirements for building a car-PC and it's software?

I am currently rebuilding a car as a hobby. As a part of it I am planning on building in a car PC with custom software for some multimedia usage, navigation and some diagnose usage. I know there are ...
20
votes
4answers
51k 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?
14
votes
5answers
8k views

Why is a 12V outlet that provides 120W protected by a 20A fuse in my 2015 Forester?

In my 2015 Subaru Forester, the 12V power outlet in the center console says that it is designed to supply loads that draw a max of 120W. To me, this would mean that there should be a max of 10 amps ...
8
votes
1answer
3k views

Battery maintainer vs trickle charger

I understand battery maintainers, like those offered under the Battery Tender® brand, are used to keep batteries charged for long term storage, and trickle chargers are.... also used to charge ...
8
votes
3answers
6k 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 ...
6
votes
1answer
4k views

What would cause a slow drain of a battery?

Have a 2002 Toyota Camry, I got a switch to disconnect the battery, but before that the battery would slowly drain if you left the car for about a week. The solution is fine for now, but how would I ...
6
votes
2answers
435 views

Why do the batteries on some cars need to be hot-swapped?

By "hot-swap" I mean ensuring that the new battery is connected in parallel to the old battery while the old battery is removed and the new one is installed in its place. The idea is to ensure that ...
5
votes
2answers
217 views

Intermittent stall at idle

I have a 98 Saturn sw2 with a recent problem. Two times now it has stalled while idling and when it doesn't stall it floats near 500 rpms (Usually 750 - 950). The first time, it would start and just ...
5
votes
3answers
8k views

Fault find blown cigarette lighter fuse

I have a 2005 ford focus mk2, nothing custom, nothing modified, all stock. The cigertte lighter has never worked so I thought it was about time I attempted to fix this. I removed the fuse (20amp) ...
4
votes
1answer
5k views

Head Lamp on Honda Shine

I'm planning to change/modify the Headlight bulb. kindly suggest. My bike (Honda Shine) has 12V 3AH(MF) Battery & Head Lamp 12V 35W/35W halogen bulb. In rainy season & city Bye-pass roads the ...
4
votes
5answers
27k views

2006 Kia Sedona intermittently not starting

What could be causing my (non-)starting issues? Occasionally (once every two weeks or so) when the keys are inserted and turned to the start position, nothing happens. No noise, no dome lights dimming ...
3
votes
2answers
16k views

Does disconnecting the battery reset on-board memory?

Will disconnecting my car battery reset the on-board memory or do I have to manually erase it to remove error codes? I ask because I have a faulty electrical system that throws gas leak errors and I ...
3
votes
1answer
8k views

What is an igniter?

In researching this question about the behavior of the tach on a Mazda Miata I came across references to a part called the "igniter" that apparently has a role in generating the signal that drives the ...