Power/Charging plans

[JJ 109]

Here are my plans for the power/charging systems. welcome your thoughts. I have investigated and do not prefer the use of a solenoid in the rear for bat line.

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[raustinss]

Ummmm fuses ?

[JJ 109]

Well, I wasn't going into that, just showing the overall layout and wire size. But since you brought it up, feel free to make a recommendation. I wasn't planning any in those circuits shown. I would add them inside where it's labeled fuse box.

[TheJDMan]

That is exactly the same layout I'm currently running with two exceptions. 1. The wire between alternator and fuse box should be either a fusible link, fused or circuit breaker. I also had to install a diode in that wire to stop it from back feeding. 2. In the 1ga wire back close to the battery you need a master cut off switch so you can kill the system and a circuit breaker is a good idea back there as well.

[JJ 109]

Thanks. What was the back feed issue that you needed a diode for?

[gray86hach]

I like to run a 4 gauge from the alt to the battery. Switch to be nhra legal for the rear mounted battery.

Tim

[Richard454]

If the wire from the Alt to the starter is routed correctly and not in harms way- there is really no reason to fuse it- much less a diode...

Look at what can happen when a wire shorts out- the alternator will go up in a puff of smoke- the battery on the other hand- is capable of welding- and making that large gauge battery wire glow bright red till it melts.

From the alternator to the fusebox- look at a maxifuse- the fuse just blows- The fusible link actually melts-and will melt stuff around it...

If you don't do a cut-off switch in the trunk- something like this might interest you- a trick looking fuse at the battery-

https://static1.pt-content.com/images/pt/2015/12/battfuse_zps924z4gla-1.png~original

[JJ 109]

Thanks to all the replies. 4gage seems like way overkill. its only a 100A alt. OEM is like 10-12 gage.

[Motobrewmaster]

Richard454,

I like the fuse at the battery terminal. Where did/do you source those. What brand it that? This would be a nice little bit of insurance in case a failure does occur. Fuse cheap... electrical fire in car...VERY EXPENSIVE and dangerous!!!

[Richard454]

Richard454,

I like the fuse at the battery terminal. Where did/do you source those. What brand it that? This would be a nice little bit of insurance in case a failure does occur. Fuse cheap... electrical fire in car...VERY EXPENSIVE and dangerous!!!

Here you go- these guys have some really neat stuff- they are across the pond in the UK.

http://www.autoelectricsupplies.co.uk/product/1024/category/192


Thanks to all the replies. 4gage seems like way overkill. its only a 100A alt. OEM is like 10-12 gage.

Yes - and remember OEM had beancounters that input on the wire size. AND don't know what car you have- but 40years ago- the manufacturers had NO idea that electrical systems in the future- would have double even triple the current output of the OEM alternators back in the day.

If you take the rating of the COPPER wire 4GU- it''s rated at 135A - but that's FREE AIR- not bundled at 70ºF. A general rule of thumb- move up a gu size for the heat under the hood... So it's really not overkill.

I am by no means an expert- I like to look at how a team of engineers handled the wire sizing- if cost was not an object. Here's a $100K when new BMW- and you can plainly see the size of wire they used.

Battery is in the trunk -the 1 gauge to the starter- the 4 directly to the alternator and 6gu to the front power distribution-fuse block

https://static1.pt-content.com/images/pt/2016/02/DSCN5074_zps8u6qw1g2-1.jpg

[gray86hach]

I like to have more than enough avaliable power. Nothing worse than a voltage drop problem that can screw with all kinds of things in the car.

[JJ 109]

I decided to go up to 6 gage

[TheJDMan]

Thanks. What was the back feed issue that you needed a diode for?

Sorry for the delay, the diode was needed because the engine would continue to run with the ignition switched off. I should also clearify that the diode is not in the alternator charge wire, it is in the voltage sensing wire.

[TheJDMan]

Richard454,

I like the fuse at the battery terminal. Where did/do you source those. What brand it that? This would be a nice little bit of insurance in case a failure does occur. Fuse cheap... electrical fire in car...VERY EXPENSIVE and dangerous!!!

I installed this double circuit breaker panel in the trunk next to the battery. https://www.ceautoelectricsupply.com/circuitbreakers.html

These types of circuit breakers are also available in 250 amp from Amazon if you want to run a single. http://www.amazon.com/gp/product/B00MR1LVZS/ref=s9_simh_gw_g263_i1_r?ie=UTF8&fpl=fresh&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-1&pf_rd_r=17HVZYW96PN2EE493VGF&pf_rd_t=36701&pf_rd_p=2079475242&pf_rd_i=desktop



https://static1.pt-content.com/images/noimg.gif

[Mark Antrim]

The jdman, are you running a ford solenoid also or just the dual breakers? Those circuit breakers are a nice touch.

[sweet motion]

m.a.d. electrical helped me-I got a solenoid in the trunk,that long 1 guage cable is only live when starting. I have 8 g wire from alt. to bat too

[MonzaRacer]

I like the Scorpion circuit breaker.
When I ran the wiring on my Monza , the yellow one, I ran a kill switch in back bumper, set my battery up in the spare tire well.
Ran my positive wire forward and up firewall to a Ford style starter solenoid, oh and I completely recommend Echlin units from NAPA, all the cheap ones stick, my application was for an 86 Ranger. I ran my starter cable above the starter and away from the headers. Shortened the solenoid wire to fir and ran my Alternator wire and all my power wiring to battery side of solenoid.
My quick disconnect switch was in my ground side of the wiring, to be NHRA legal I would have wired two switches, making it cut the negative first then the positive.
I used a CSI 133 105 amp alternator with no issues. If I had to fuse the alternator wire I would use one of the big oem maxi fuses.
Also the big breaker would trip if your starter goes bad.
The reason I cut my ground is that electronics hate having positive sides broken abruptly. If electronics lose ground they generally dont blow, they just shut down.