electrical guru's - dual battery w/ winch wiring

[SDlivin]

Primarily looking for advice on what type and where to put in fuses in the wiring config that I describe below. Or if something is obviously not wired correctly.

Not really interested in discussing the pros/cons of isolators, dual batt set-ups, etc... Stuff has already been purchased and installed.
Already installed the dual battery (opposite side of engine bay), and installed the Painless dual battery wiring kit. Painless Instructions say to wire winch direct to main batt which leaves aux batt as back-up if needed. I will also be using Aux Batt as primary for aux power needs; lighting, fans, etc...

I'll try to explain how I have it wired, and you keep me honest.

Winch wired direct to + and - posts on main batt. Winch instructions say there is a built in fuse in winch wiring control box.

+ post of main batt to primary terminal of Painless Solenoid (not fused). Primary terminal on Painless Solenoid to Starter Solenoid (not fused).

+ Alternator post to 175a mega fuse to Starter solenoid.

- post on main batt to mounting bolt on alternator for ground.

+ on Aux Batt to secondary post on Painless Solenoid (not fused).
- post on Aux Batt to frame.

MSD 6al box wired direct to + post on Main Batt (not fused, per directions on MSD).

That's it.
Where else should I have inline fuses and what type is recommended?

Thanks.

 

[Broncobowsher]

Post on aux battery to frame, move that to the engine block/alternator instead.
Unless you run another heavy ground cable the frame is rubber isolated from the engine (charging/starting loads) and body (lighting loads). The engine and body all sit on rubber mounts to the frame.

No problems using the frame as a ground. But you are just adding more junction points in the wiring.

The main battery positive I would run to the starter solenoid first, and run a jumper from that to the isolation relay. Fewer junctions between the battery and the starter.

What alternator output are you going to run? Unless you want to risk popping that 175 amp fuse, loosing your whole charging system and maybe damaging the alternator I hope you are not planning an alternator of more than 150 amp.

 

[SDlivin]

Good point on the aux ground. While I do run a ground wire from engine block to frame, I think I will run aux ground to block rather than frame.

I did the explorer serp swap awhile back so if I recall the 3g alt is 130 amp. So might be better off with a 150 amp mega fuse rather than the 175a ?

any other place to use a fuse, breaker, etc....

Thinking of doing a switchable breaker on the winch line. Keep it switched off until needed.

And maybe something from the + Aux batt to solenoid? or no?

Thanks for the input.

 

[Broncobowsher]

The 175A is fine. You don't want the rating too close to the capacity. It is just there in case of a catastrophic failure. I was just looking at an OEM wiring diagram for something unrelated and the fuse rating was 50A higher than alt output.