Power Source behind Air Filter?

[Spool]

Hey Guys.

(First off a wiring harness is on the near future to do list.)

For now, behind my air filter on the firewall, there is a bolt with a few things receiving power from it. The stereo for certain.

Where is it receiving it's power? Connected to the battery directly?
Photo attached.

Thanks guys.
-Thomas

[75gmck25]

The  main power junction (looks like the one in your picture) is usually mounted on the firewall on the passenger side of the brake booster.  That junction has a main power wire coming straight down out of it, with a fusible link.  The power wire runs down, over across behind the engine, and then down to connect to the large lug on the starter.  The large battery cable is also on that starter  lug.

From the junction next to the brake booster there is usually a wire running over to power the fuse box, a wire with an inline fuse running over to the blower relay for the A/C, and maybe at least one other wire.   

Based on the picture, the junction you have seems to be one that was added, more toward the middle of the firewall.

Bruce

[Spool]

Thank you Bruce.
I've been eyeballing the positive wire from the battery to the starter lately; it's much too short and needs to be replaced.

Next question is, would this power junction be any less quality of power than directly to the battery?
I currently have my stereo hard wired to the junction; thinking it may be the reason the power drops our once in awhile on the stereo unit.

Thank you again Bruce.
Much appreciated.

[75gmck25]

The one advantage of running your stereo power directly from the battery instead of that junction is that it may reduce the voltage drop when other accessories kick in.

For example, the line that runs over to the blower relay from that junction has a 30 amp fuse in it, and mine used to often blow that fuse.  That means I had more than a 30 amp draw when I flipped the blower on high or turned the A/C on max.  That's quite a bit if I still had the stock 63 amp alternator.

The radio head unit probably has quite a bit of tolerance for voltage drop, but external amps or sub-woofers need all the power they can get.

Bruce

[VileZambonie]

[haroldwca]

The one advantage of running your stereo power directly from the battery instead of that junction is that it may reduce the voltage drop when other accessories kick in.

For example, the line that runs over to the blower relay from that junction has a 30 amp fuse in it, and mine used to often blow that fuse.  That means I had more than a 30 amp draw when I flipped the blower on high or turned the A/C on max.  That's quite a bit if I still had the stock 63 amp alternator.

The radio head unit probably has quite a bit of tolerance for voltage drop, but external amps or sub-woofers need all the power they can get.




Bruce

I guess it's one of my pet peeves to open a hood and see wires running from places other than where they were designed to be. If your supply wires from the aforementioned junction block to your stereo and also from the battery to the junction block are in good condition (not frayed or old and oxidized) and of proper diameter, you will not be able to benefit from running a wire directly to the battery.  This is true unless you are running an external amp (which draws an extra amount of current), in which case you are probably at the limit (or close to it) if you are still running the stock alternator, no matter where you have it wired. 

Also, if your blower is drawing more than 30 amps, check your ground on the blower.  The blower, itself, also may be so old that the windings in the motor have degraded and the motor exhibits more resistance than originally designed.  If so, replace it.