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[COLOR=#141414][FONT=Tahoma]I have battery on the driver side, and starter motor on the passenger side...I don't love having over 3' of large cable to run to the positive side of the starter, but it'll have to work. So what about ground....would it be better to run the ground the long distance to the starter motor, or better to just run a short ground to the engine block on the driver side? Or does it not really matter either way?[/FONT][/COLOR]
I'd go close side of the block / same chunk of metal the starter bolts onto as first option.
[quote=FINOCJ;345911].I don't love having over 3' of large cable to run to the positive side of the starter, but it'll have to work.[/quote]
Do know, some factory performance cars place the heavy battery in the trunk and run those cables all the way to the engine bay...
Keep the routing safe and the length as short as reasonable and go for it.
[QUOTE=Jim;345916]I'd go close side of the block / same chunk of metal the starter bolts onto as first option.
Do know, some factory performance cars place the heavy battery in the trunk and run those cables all the way to the engine bay...
Keep the routing safe and the length as short as reasonable and go for it.[/QUOTE]
I owned a Saturn Ion that had the battery in the trunk. Not much of a performance car though.
Grounding to the block is fine. Remember a second ground to the chassis/firewall.
I remember pulling battery cables from an Audi at the junkyard, well over 5 ft long, and sized for the current load. ;)
I have been thinking block too, though no expert. My thinking is that if the chasis and block aren't grounded properly you'd gave other issues than just not starting.
I vote block as well. I like to use a 0 gauge wire. I also put a grounding strap between the block and the frame. And one to the body. Those are usually smaller but still substantial.
Traditionally, you would ground the battery to the block through the starter neg post (its grounds to the block through the starter mounting). So, in theory, you can ground the battery directly to the block and let the starter mounting connect ground to the starter. Usually, its easier and closer to ground to the starter post, and you probably get a better cable connection to the starter post and and deeply threaded mounts into the block, than a cable held against the surface with a bolt (hopefully grounding through the head of the bolt into the threads).
In my buggy the battery is in the passenger side rear corner of the "cab," easily 6 feet of cable running to the starter, no problems.
Went to jump a friends WK2 Grand Cherokee and couldn't find the battery. They have a couple of terminals in the engine bay which is nice but the battery is under the passenger seat. Kinda weird and not sure I would feel awesome about being the passenger.
I know that many run batteries from far away - never optimal, but certainly doable. The question was more about how to best ground those types of circuits....Anyway, I am going to try grounding to the rear of the block near the battery, and am also running a ground cable from that spot on the block to the frame, and then a ground from that spot on the frame to the body. I hate messy wiring (the cj5 is starting to get on my nerves with the under-hood wiring - its not horrible, but it could be cleaner).
That reminds me - family's ?1980? MG-B, the battery is below the rear passenger side seat.
[quote=FINOCJ;345928]I am going to try grounding to the rear of the block near the battery, and am also running a ground cable from that spot on the block to the frame, and then a ground from that spot on the frame to the body.[/quote]
Well that plan didn't work...too much stuff happening on driver side rear of the block with the through the floor pedals and steering column, horn wire and ground, to have extra wires etc running between the block and frame and body. Plus, I know exhaust will have to squeeze in there as well. So it looks like I will ground the battery to the rear driver side of the block, but then will ground the block to frame on the passenger rear - possibly even using the starter ground post. Will run that frame ground to the body as well on that side. There is a lot more room on that side as long as everything is kept high above the exhaust, which will have to be a bit high to stay above the front driveshaft.
My G-Wagon battery is the rear floorboard, behind the center console. As I've heard it the main thing is to choose one ground and ground everything there, often it's the same point the block, chassis and negative terminal all come together but on my G it's negative -> frame -> block. My chassis is also grounded to the frame. I see winch and air compressor manufacturers tell you to ground directly to the battery but I think that is mainly so they don't have to be blamed if you have a bad chassis ground causing voltage drop and blame it on their product, but I have a good chassis ground and run my winch and air compressor both to the frame.
It's probably not a big deal with winch, starter, and compressors as they have large cables that can handle the current of a dead short, but what I have been told is that if you run small accessories directly to the negative terminal, then later have the frame ground go bad or get disconnected, then you run the risk of a high amp accessory trying to find ground through another accessory with a much smaller wire, then overheat that and cause a fire.