Well there goes my fun...

[Alex K]

Lol dude you just unhook the negative terminal??? and make sure its not touching the battery

WRONG you always, always, ALWAYS remove the positive terminal. If you just disconnect the negative terminal that terminal can touch ANYTHING metal and ground

out.

You always disconnect negative.

Every manual you'll ever read will tell you the same.

So how is EVERY electronic company wrong?

I understand what you're saying though

You can dissconnect whatever terminal you want. But youre wrong on the fact that if you dissconnect the negative then touch the positive to the car, you'll short it. Not going to happen since theres no other wire touching the - of the battery. you do know you have to connect the same batteries + to - to fuck shit up right? How does touching the + wire to the chassis when its unhooked do anything? it doesnt. i've touched + to the car all the time. It's like buying a new battery and having a wire from the +, just attached, then touchint it to your car. Nothing will happen because the - on the battery is not connected to anything.

[Parentnoia]

I'm thinking of doing big three (or at least buying the wire) this weekend. Not because of issues with my system itself, but with the fact that my lights dim when starting my car... Also, does anyone know what would cause my highbeams to not work? Headlights themselves work but when I flip on highbeams, the switch off and leave my fog lights on.

why do you care if your lights dim when starting? your starter is pulling a few hundred amps out of that battery for 2 seconds and you're worried about lights dimming? that should be the least of your concerns if your lights dim when starting.

They stay dim...

[Guest]

They stay dim...

what is your battery's resting voltage. should be right around 12.6v. and what about when the car is on? what is your voltage then?

[Parentnoia]

No clue. How do I check?

[Guest]

No clue. How do I check?

...multimeter. attach probes to battery. switch multimeter to DC volts

[Parentnoia]

I don't have a DMM.

[JaM Customs aka mprete]

does your car have a volts gauge on the dash?? also you should disconnect the negative cable first. it makes since to do positive but like someone already said if the battery neg isnt hooked to anything then the battery is not grounded and it will not have a route to flow current. and if you disconnect positive, because it has a ground the terminal will spark when you reconnect it and a spark on top of a battery that is full of highly flammable gasses WILL explode. very unlikely to actually happen but who really wants to take the chance... and please im not just some kid taking a wild guess at this i am a mechanic and know what i am taking about.

[Bakerman]

Honestly there is a good trouble shoot to this. Take the HU out with its wiring harness. Put the yellow and red wire together, and touch them to the positive side of the battery. Then touch the black wire to the negative side of the battery. (or any DC power source you may have, i always use a standard car battery charger) If the radio comes on when you straight wire it like this, then you probably just have a wire inside the car that got hot and melted when you had the spark. This is common, and used to happen to me all the time when I didn't know what the crap I was doing. If the radio doesn't come on, then I hate it, but you're gonna need a new one.

[JaM Customs aka mprete]

so your all good to go then?

also you said the test light method didnt work.... if you touched power and the light didnt go on then you did not have a good ground. or if its your dads old one that hasnt been used for 20 year or something then the light in the test light could be burnt out. so check that by simply touching the clip to your neg batt terminal and the probe to the positive end and let there be light. if it dosnt come on... get a new light. if it does then you did not have a good ground or there was no power at the wires. also remember, for power to be at the red wire the key has so be in the on position....

[bassl0va]

I don't have a DMM.

You can get cheap ones for like $10, well worth it.

does your car have a volts gauge on the dash?? also you should disconnect the negative cable first. it makes since to do positive but like someone already said if the battery neg isnt hooked to anything then the battery is not grounded and it will not have a route to flow current. and if you disconnect positive, because it has a ground the terminal will spark when you reconnect it and a spark on top of a battery that is full of highly flammable gasses WILL explode. very unlikely to actually happen but who really wants to take the chance... and please im not just some kid taking a wild guess at this i am a mechanic and know what i am taking about.

If you do negative first, then positive, you won't scare the crap out of yourself when you accidentally hit the car body (or other grounded part) with the spanner/ratchet. I think everyone's done that before, haha.

You may be a mechanic, but you mustn't be an electrical engineer. You should know that it doesn't matter which part of the circuit is completed, if there is going to be a high current draw when the circuit is completed, there will be a spark.

And there is a very very small chance of getting a explosion in the open air. Now charging the battery in a small room and lighting up a cigarette, that's a bad idea.

I just remove my main fuse up by the battery when working on the amps, every other time it's negative first, then positive.