Chaser Electronics hook up

[Steve Polley]

This makes total sense to fuse the negative side as well. Current flows through the ground side of the circuit just as it does in the positive side. This is a know series circuit law. Some commercial and amateur radio equipment come with fuses in both the positive and negatives sides stock. I teach these theories and practices for a living and its one of the hardest thing for aspiring technicians to understand.

Ground to vehicle or the battery.. Either is fine... But, make sure if you are creating your own ground lug in the vehicle, to scrape off all paint to that it makes a good ground...

Also... FUSE THE NEGATIVE SIDE TOO!!!!!

I know it sounds weird, but with starter, engine, or alternator problems, sometimes voltage is thrown across and will feed back on the negative side... I install emergency equipment on squad cars and was one of the first things I was told......

As everyone else said, go to a battery, dont use cig plug unless for one item, or small things like radar detector, xm radio, phone charger etc..

Have a good alternator, I have a 160 amp High Output Alternator.. Came standard on my car...

Have a good battery, chase conditions can lead to warm starts, periods with equipment left on etc... I have an Optima Red Top Battery..

Finally, be able to turn your equipment off.. I have a master switch in my car, but all my equipment is wired through a controller in line with battery that kills it after 1 hr of the vehicle being shut off, and turns it all back on when the vehicle is started..

 

[Steve Polley]

You have to also understand there is such a thing known as voltage drop in circuits. If the voltage drop is to high while the circuit is in operation this is just the same as having high resistance in the circuit which will limit current flow proportionally. Current, not voltage, does the "work" in a circuit, ie. making the radio transmit at full power, inverter working at its maximum possible wattage, etc. Voltage is just the force behind the current flow. Sorry, had to get that off of my chest lol.

Doing things "right" is way overkill for what most chasers use. Using the power point or cig lighter to power everything is ok as long as all the stuff combined does not pull more amps than what the circuit can handle. A powerpoint circuit can handle many low power devices, since it was designed to handle huge spotlights and the like. The only reason I wired my inverter directly is because I was getting some voltage drop through the extra wiring and my (sensitive) inverter was shutting down, when I would start my vehicle. If it weren't for that I would be doing everything through the power point including my inverter... I'm not going to be running a skill saw with my inverter. One mega candle power spotlight can draw more amps than all of my stuff combined. It all has to do with what the total amperage is for the circuit when everything is running. If your power point... what ever it is, is fused with a 20 amp fuse for example, theoretically as long as you stay under that your ok. In real life you want to be significantly under that. I have seen fuses get hot and melt without actually blowing when the amperage stays near what the fuse can handle.

My truck came with two batteries... but in reality you don't need two batteries, unless you sit with the car engine off and everything on for an extended period of time. I love the ability to do that and do it regularly on lightning shoots for several hours. The only time extra battery power is needed is when the engine isn't running. You don't need a high output alternator.

Having 4 gauge wire and two batteries with a distribution box and a big alternator is great... it all looks cool.. and it is needed for car audio set ups and the like... or trucks with lots of lights, maybe even some high powered radio setups which some chasers have... don't know much about that... but not for low power stuff. It's like shooting a deer with a 50 caliber rifle when a 243 will do the job.

And I agree, a shorter wire is always better, doesn't matter what you are doing with it.

 

[Wes Carter]

This makes total sense to fuse the negative side as well. Current flows through the ground side of the circuit just as it does in the positive side. This is a know series circuit law. Some commercial and amateur radio equipment come with fuses in both the positive and negatives sides stock. I teach these theories and practices for a living and its one of the hardest thing for aspiring technicians to understand.

But there is another law, Kirchoff's voltage law, that states that in a complete circuit that the sum off all voltages will always equal zero. If you get an open in the circuit, such as where the fuse blows, everything in that loop will have a voltage potential of 14.4 volts to ground, which consists of all things metal in the car. If the positive side fuse blows, then everything will have an effective 0 volts potential to ground and all metal parts of the car. The positive lead should be fused as close to the battery as possible and should always be the weakest link in the circuit.

Normally fusing the ground lead would not be a problem and does offer some redundant protection. But there are some drawbacks. Fuses are the most common electrical component to fail, and it's not always due to a circuit fault. The filament can be damaged by vibration, the fuse holder can develop corrosion, and they can fail for variances in tolerance (normally plus or minus 5%, but can be more) among other things.

If you want to have redundant protection, you will also have redundant chances for failure. What might be an ideal setup in this situation would be to fuse the positive lead with a relatively fast acting fuse rated properly sized, and a slo-blo fuse on the ground side. That way, you are almost ensured that the psoitive side will blow first. But if your load is prone to spikes and transients, then that might not be an option as the fast acting fuse might go frequently in normal operation. In that case, I'd use the proper size slo-blo on the positive, and a slightly over sized fuse on the negative. Although I'd never reccomend using an over sized fuse, in this case since it is there to provide redundant protection I'd make an exception. But if it were me, I'd forgo the ground fuse. There's a good reason that Ford, Chevy, Toyota, Honda, Mercedes, Nissan, and even racing entities such as NASCAR don't use them.

 

[Steve Polley]

But there is another law, Kirchoff's voltage law, that states that in a complete circuit that the sum off all voltages will always equal zero. If you get an open in the circuit, such as where the fuse blows, everything in that loop will have a voltage potential of 14.4 volts to ground, which consists of all things metal in the car. If the positive side fuse blows, then everything will have an effective 0 volts potential to ground and all metal parts of the car. The positive lead should be fused as close to the battery as possible and should always be the weakest link in the circuit.

True statement. But also, current is is the same throughout a series circuit.

But if it were me, I'd forgo the ground fuse. There's a good reason that Ford, Chevy, Toyota, Honda, Mercedes, Nissan, and even racing entities such as NASCAR don't use them.

Not always the case. For example, there is usually two forms of circuit protection in factory power window circuits. One in the fuse panel and another built into the motor. This is the case alot in door lock circuits as well. For me, It may be overkill for some, but I will go on the side of caution and fuse both the low and high sides of the circuits.

 

[Wes Carter]

True statement. But also, current is is the same throughout a series circuit.

That's true. But that has no relevance to the issue.

Not always the case. For example, there is usually two forms of circuit protection in factory power window circuits. One in the fuse panel and another built into the motor. This is the case alot in door lock circuits as well. For me, It may be overkill for some, but I will go on the side of caution and fuse both the low and high sides of the circuits.

Oh, there are more places than that that have double protection. Your car stereo usually has an internal fuse for another. Some instrument clusters have them. But not on the negative (ground side). I'm not saying double protection is a bad idea, but there are some risks to having a fuse on the ground lead. If the ground fuse blows and the positive fuse does not, everything in that circuit could potentially come in contact with ground where it is not supposed to and complete the circuit. If a fuse opens on the positive side, it doesn't matter what touches ground. It's all at the same potential. It would actually be safer to put two fuses in series as close to the positive terminal of the battery as possible. You would have your redundancy and avoid the possibility of having a circuit with a fault (ground fuse blown) yet still live in reference to ground.

There are some systems that I can think of that have circuit protection in both legs, but they are ungrounded systems (boats and marine systems come to mind). It is an industry standard to always put the circuit protection on the non-grounded or non-neutral side. It's for the reason I described.

http://www.allaboutcircuits.com/vol_1/chpt_12/4.html