Check my wiring plan please

**[H]Bugster** · 01-11-2004, 05:42 PM

Please tell me if i am doing this correct or wrong. THanks

**fantomas** · 01-11-2004, 05:49 PM

Originally Posted by [H]Bugster

Please tell me if i am doing this correct or wrong. THanks

yes...as long as the fuse is at MOST 18" from the battery (the shorter the better) and the carputer includes a voltage regulator/powersupply etc...

**MikeH** · 01-11-2004, 05:55 PM

Bugster,

What type of power supply does your carpc have? (ie is there an external adapter of some kind?).

**robiewp** · 01-11-2004, 05:58 PM

Originally Posted by fantomas

yes...as long as the fuse is at MOST 18" from the battery (the shorter the better)

want to tell me why?

**[H]Bugster** · 01-11-2004, 06:00 PM

im using the PW70A with ITPS for my carpc.

**samc** · 01-11-2004, 06:07 PM

I would like to know also..but thats the general rule of thumb when you install amps

**MikeH** · 01-11-2004, 06:13 PM

Bugster,

I'm not an expert on the PW70a but their spec sheet says it's input needs to be 12v+/-15%, which means it can accept 10.2v - 13.8v. The upper end may be marginal if connected directly to your battery/alternator. If you use the ITPS in front of the PW-70a as a pre-regulator, the ITPS needs at least 13.3v input to provide a regulated 12v out. Quite frankly, I'm not sure how they recommend you connect these to get a reliable PS. Perhaps they want you to feed the battery directly into the PW70a and use the ITPS in parallel just as a shutdown controller...... I'm stumped..

**DodgeCummins** · 01-11-2004, 06:53 PM

The fuse protects the vehicle wiring. The farther the fuse is from the power source, the more likely damage or a short circuit will burn up the wiring.

If the fuse is right at the battery, then a short will blow the fuse...with no damage.

If you have 20' of wire, and you get a nick in a wire along the way, between the battery and the fuse, the wire will continue to try and conduct the electricity until it glows red hot (like a light filament) and sets the interior of your car on fire.

**Jackso** · 01-11-2004, 09:05 PM

Originally Posted by robiewp

want to tell me why?

18" is the standard "rule". It's to minimize the chance of shorting to the frame before the fuse, and to prevent overheating of the wire. A seriously undersized wire will still carry a lot of current if the run is only 18", thus allowing it to blow the fuse before the wire burns up. If it were a long run, the wire would melt before it could blow the fuse.

**sxpert** · 01-12-2004, 05:17 AM

Originally Posted by robiewp

want to tell me why?

you need to have the fuse closest possible to the battery so that it actually protects the actual wire that takes the electricity from the battery to the carpc. the fuse is what is supposed to blow, not the wire burning up in case the power supply shorts itself (unless you want your car destroyed by an electrical fire)