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10

Xenon headlights require different electronics to drive them, but they also need different reflectors and also a light leveling system to prevent blinding the drivers of other cars, because the HID lights are so much brighter than traditional lights. If you look closely at a car with HID lights, with the lights shining on something in front of them, you ...


9

Standard digital multimeters can measure current and help you identify what in your vehicle is consuming your battery's juice. Get an electrical diagram of your vehicle and try to narrow it down by doing current measurements in the various major paths of flow. When your car is off, no (or only trace) current should be flowing. Every time the path of ...


9

The Body Control Module is a computer which controls many things in your car not directly related to the engine. Instead of large wiring looms en relais and circuits all over the car all the buttons connect to a single computer which in turn turns on the headlights, open the windows, control the central door locking, etc. A good example is the VAGCOM system ...


9

If the battery dies whilst driving, but you can jump it off another car, you want to look at the alternator first (possibly followed by the battery, the wiring and any large loads, because either your battery is not charging or something is draining it faster than the alternator can charge it) An alternator should give somewhere over 13 volts (often 14.5) ...


7

Apparently, this is the Mazda limp home mode. If you check that link, two common causes are: Vacuum leaks Bad ABV solenoids In discussing with your mechanic, I would suggest first having them scan for codes to see what is triggering the limp mode.


6

Sure enough, you've got a damaged wire that is shorting out the entire electrical system. So think about what happens when you press on the brake pedal, it sends power to your brake lights at the back of the car, so if one of those wires were shorting, you would only notice it when you tap the brakes. The weird thing is, this doesn't happen very often, ...


6

I'm sure you could manage to measure the amount of energy wasted by your condenser fan, but I promise you it's statistically insignificant. If you're trying to save an amp or two or power, it would make more sense to make sure you don't have any lights on or that you're not carrying any heavy objects you don't need in your trunk. That said, the most ...


6

This is normal behavior. The A/C system is turned on to dehumidify the air, which causes the windshield to defog. Without it, your breath would freeze on the inside of the windshield and cause further issues. EDIT: Please note Bob Cross' comments below. I found instructions on the Honda Tech Forum which is supposed to give you full manual control over ...


6

Most modern diesel engines (ie: engines after mid-80s) require some electricity to run because they are electronically controlled. This is due to computers controlling the fuel charge and monitoring of the engine itself. Without this, the diesel engine has no control. They also require electricity to power the primary fuel pump, to move the fuel from the ...


5

Here is a diagram for the basic 4 wire trailer. Yellow - Left Stop/Turn (the big filament as you described in the left bulb) Green - Right Stop/Turn (the big filament as you described in the right bulb) Brown - Parking/Marker lights (the small filament as you described in both the right and left side bulbs) White - Ground They all hook to the ...


5

Measuring the state-of-charge of a lead-acid battery is non-trivial. The easiest way is to use a voltmeter. You'll need a digital meter with 3 1/2 digits of precision. Let the battery rest, disconnected, for 24 hours. Then measure the voltage across the terminals. According to http://www.phrannie.org/battery.html, anything over 12.60V is at least 85% ...


5

I'd check the ground strap/contact to ground from the blinker to the chassis first. Chances are there's a problem with it an it "grounds" via another bulb when you also apply the brake. Using a multimeter, check the resistance from the ground on the bulb holder against the chassis first, then check blinker ground against both contacts for the brake light. ...


5

Most water pumps are designed with a weep hole.This is a small hole that leaks a small amount of antifreeze just before the water pump fails.Most of the time the leak is just above the crankshaft pulley.When you shut off the car the pressure in the cooling system forces some coolant out this hole and it drips onto the pulley and is transfered to the ...


5

As Bob says, formal servicing should always follow the manufacturer's schedule - Make sure to take into account any variations suggested for your location/climate/usage pattern. This should include routine things like oil and filter changes, as well as more major, but less frequent things such as timing belts. In terms of more general checks and ...


5

Most of the time a ground loop is the cause of this problem. This problem is common especially if your stereos speakers are amplified, and can be fixed my making sure that your stereo unit and/or amplifier have a good ground connection. This can be done by either finding a more direct ground connection to the cars frame, sanding the area around your ground ...


5

If you are not familiar with the electrical system I would get a referal to a good shop familiar with BMW's. They may have seen it before or at least recognize what caused it. This a case where it must be determined if your melted wires were the cause or the result of another problem. Just installing another harness may result in the same melted wires. The ...


5

It sounds to me like a dead battery. Depending on how accurate your voltmeter is, what you see as 12V may be 11.9V or lower. To give you an idea, an open circuit battery terminal voltage of 11.7V indicates a completely uncharged battery. What you are describing happened to me once with a Volvo car, due to a faulty switch in the glove-box; the glove-box ...


5

You should be able to sneak a clamp on to the positive terminal, and there's an auxiliary negative (ground) terminal lug nut to clamp onto right in front of the coolant fill tube and power steering fluid reservoir. Otherwise if you really want more room, you need to remove the intake tube (nothing to do with exhaust) by disconnecting it at the rubber ...


5

Probably not, but maybe in some circumstances. I've had 4 alternator failures in my life. 1) Toyota MR2 - Alternator diode blew up (big bang and smoke) while driving on the expressway. No prior warning. Just BANG! and was suddenly on battery. 2) Toyota MR2 - Alternator casing broke causing the alternator to bind up and jam (with loud scraping and ...


5

This is actually much simpler than that chart implies. Don't worry about ohms per thousand feet - for a four foot length this will be very very low. What is more important is the maximum current a wire is rated to. So here the question is whether you will want the OO gauge as it is rated to 190A in the power transmission column, or the 2 gauge as it is ...


5

No, I don't think you fried anything. All that's happening is that the electrical system can't supply enough current to power the starter motor, so the voltage drops when it tries to. The "clicking" sound is the starter solenoid. When the voltage drops from trying to operate the motor, the solenoid (big relay) no longer has sufficient power to keep it ...


5

I believe that you're talking about the Fuel Vent Canister / EVAP Canister. It is located underneath the vehicle and mounts to the drivers-side frame rail slightly behind the drivers side door area (about the center of the vehicle). Here is a photo for you to compare the part to.


5

If you place a jumper wire between a always-on 12V source and a switched 12V source, you've now turned your switched wire into an always-on wire (with power supplied from your original always-on source). This is not advisable, and is almost certainly not what you want. It could also create a risk of fire if the fuse for your unswitched source is too large ...


5

Your description of connecting the two cars is correct. I want to emphasize making the last connection to the "bolt head" you mention. Any large piece of unpainted metal will do. The reason for this is to keep the resulting spark away from the battery. If they battery has been venting fumes, the spark can (although very unlikely) cause them to ignite and ...


4

There are only a few parts in play here. The reverse light switch in/on the transmission, the wiring to the rear of the vehicle, the tail lamp assembly, and the lightbulb itself. I would check the bulb first. If the filament is broken in just the right way, it can cause the flashing symptoms that you're experiencing. The part number for the bulb is 3156 ...


4

I don't know if it's common for them to malfunction, but assuming there are no leaks in your tire the pressure at 25F is about 10% lower than at 70F which is probably enough to trip the sensor. I have a BMW with TPMS and any time the temperatures drop quickly the light comes on my dash. If the temperature drop is temporary and things warm back up later in ...


4

In addition to an unexpected electrical load, as covered by Captain Claptrap, there are other things to check. The two biggest killers of lead/acid batteries are overcharging and vibration. Unless you have the equipment and the skills to use it properly (in which case you probably wouldn't be asking) I suggest you get the charging system checked by an ...


4

First off I can say that I have done something like this, but with the ignition and not the horn - my friends ignition switch broke so we wired a bright red push button directly from the battery (well - actually a fused 12v line inside the car) to the starter motor coil - it has since worked like a champ for nearly two years. First off - DO NOT wire ...


4

If you're looking for personal use and already have access to a laptop computer, I'd highly recommend getting a PC (or Mac, if that's what you have)-based one. You buy the hardware, generally for $100 or less (I recommend the units from ScanTool.net - the less expensive ones are fine). The biggest advantage is that you can start out with the free software ...


4

My immediate thought there was the flasher relay. Pull this out and either test it outside the car or swap it for a known-good one. If that is not the fault, then as you rightly point out, you need to make sense of the wiring diagram... The key thing here is the wire colours. Most cars have two-colour wiring, with a main colour and a trace colour (i.e. the ...



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