My trunk mounted battery shamozzle

[Healey3000]

I'd be more comfortable using heavier wire than 4 AWG (21 mm2), given that it's running quite a long way.  2 AWG at a minimum but that's just me.  For things like this, I look up the wiring diagrams of more recent cars, such as the e30.  For a rear-mounted battery, the 318is (M42) uses a 50 mm2 cable.  That's even larger than 2 AWG.

[AustrianVespaGuy]

No bad advice in this thread so far, so I'll try not to reiterate too much, but I'll add a few things to the conversation.  Along with Healey's advice, I'd suggest 2 AWG wire size for the LONG 6-foot-ish cable run from the back up to the engine bay.  But for shorter runs, say the battery ground to the strut tower, that 4 AWG wire is probably OK for just a foot or so.  I'll also second Steve's advice that great short cables are inexpensive at Autozone/similar.

I'm in favor of the Odyssey AGM batteries under the back seat so as not to clutter up the trunk (what I run), but good reasons NOT to go this route are that you already have holes drilled in you strut towers for the rear battery/brace OR if you don't need the room in the engine bay, the much-smaller-much-lighter Odyssey battery can easily just go in the stock spot too.  All worth considering while you're redoing battery wiring stuff though for sure.

As for fuses, they're great safety devices, but a few words of caution; if you add in fuses, make sure you do a good, careful job of it so you're not just inducing additional failure points into your electrical system.  Every cut/splice adds to this risk.  Also as Toby indicated, I prefer to fuse individual loads rather than the whole system.  Right now if you get a short somewhere and blow that 50A fuse, well your entire electrical system goes down and you don't really know where to start looking for the fault.  So a fuse in JUST the starter +12V cable and another in JUST the alternator output are the smarter way to go about trying to fuse-protect the high current stuff, in my opinion.  You'll want to figure out where those 4 wires are all going though, some of them might go to systems (like the lights) that are already fused further downstream, in which case you DON'T want to add more fuses, see my argument above about additional failure points.  Last thing on this, and some may argue it, but just like the factory setup, I don't like to run a fuse in the ignition circuit.  Make sure those connections are all very good and safe, and avoid the risk of getting stuck on the side of the road not realizing your car won't start because the coil voltage is too low because of a corroded fuse connection.

[jp5Touring]

Thanks to all the input so far, bunch of great people on here.  I  purchased one cable while I was out today.

Interstate Batteries made one to my specs in 2 gauge. He has to order  more red so I can get the battery to starter cable in 2 gauge.  So next week for that  cable. About to go figure out what the 4 wires on that block go for sure.

 

A little tider 

 

[jp5Touring]

So dive in, to figure out my little wiring block. Removed some of the fabric tape to clean up the wiring.

The power wire from my starter to the 4 wire 50 amp fuse box is this little gem, the wire under the fabric tape just didn't 

fill right.  What the hell.

  

[Healey3000]

Nice!!  Aren't you glad you dove in ?

 

This might be a good time to step back and see what else was "upgraded" in the electrical department.  You may have more crimp lugs, eyelets, wire, tape and shrink tubing in your immediate future.

 

An e30 or e36 junction box would be a nice way to obtain a clean, safe, and OEM-quality connection.  Make sure you get the correct size lugs (both for the hole ID and the wire gauge).  You'll sleep better as will your car!

[jp5Touring]

So made some progress, wired my alternator directly to the starter solenoid. With out a fuse, correct ?

Also traced the other 3 power wires, fan relay, ignition/key,  and fuse #7.

So if I'm right I just need a terminal bus bar for the 3 wires. 

I planed to use 12 gauge from starter to bus bar, two feet at the most.  12 gauge adequate ?

 

A little better wiring for the starter.

 

Is this attached to the #6 or # 7 fuse ?  It should be # 7. All the green tape clean up is for another day.

 

[Healey3000]

Hi,

 

12 AWG to feed the entire car does not seem sufficient.  That's only 3.3 mm2; you'll need at least 6 mm2, if the factory wiring diagram is to be believed (I'm going by the '74 diagram)..  My recommendation is 10 AWG minimum, 8 AWG preferred.

 

I tend to go oversize a little on power wiring because I always assume my hand-made crimps are not going to be quite as good as the factory crimps.  For the minimal cost increase, why not?

[jp5Touring]

I can do 8 gauge, I didn't think I was powering the whole car just those three power points.  

Everything works, but for some reason my turn signals don't.  My flashers/hazards work and all the lights work.

I must of bumped something, I think I have a spare flasher relay.    

[jp5Touring]

So I finally wrapped up most my electric issues. Rewired my 50 amp fuse that I think is used for a forklift from what I found.

I updated all the connection, upgraded to heavier gauge wire where needed. Bought some Tesa tape and rewrapped a third of the engine bay.  Thanks to everyone that provided great info on how to straighten this out.

 

My old forklift amp

 

My new busbar

 

 

 

[Healey3000]

Nice work!  If you can find a cover for that bus bar, it would add some protection against stray tools and such.

[jp5Touring]

9 minutes ago, Healey3000 said:

Nice work!  If you can find a cover for that bus bar, it would add some protection against stray tools and such.

 

Thanks, It does come with a cover, I thought my wiring turned out pretty decent.? So took pic without.

I did upgrade the starter and alternator wire to 8 gauge per your suggestions. Thank you  Cleaned up the engine bay grounds also.

I actually think it idles better and starts easier with the better grounds.  I want to move that fuel regulator to, always seems to get in the way of something. Just run it up the firewall side I think.  Ah project creep,,,

[Healey3000]

2 hours ago, jp5Touring said:

I want to move that fuel regulator to, always seems to get in the way of something. Just run it up the firewall side I think.  Ah project creep,,,

Interesting, are you using the fuel return line as the feed?  That looks like a fuel filter.  Normally, the filter is on the line coming through the firewall, with a more direct and less obtrusive run to the carb.

[AustrianVespaGuy]

9 hours ago, Healey3000 said:

nteresting, are you using the fuel return line as the feed?  That looks like a fuel filter.  Normally, the filter is on the line coming through the firewall, with a more direct and less obtrusive run to the carb.

I agree that fuel line is REALLY strange looking.  My guess would also be the the return line is being used for the supply (actually a good choice as far as I'm concerned), however there's absolutely no reason to run it that far forward.  Instead the rubber line should come up the firewall next to the pedalbox and then cross over the back of the manifold and on into the carb.

 

Very nice job on the rewiring so far, but I too will strongly suggest that you safely cover up any of the exposed +12V connections (bus bar, starter, alternator, etc.)  You'd be surprise how easy those are to touch with a ratchet handle when working in there, and the next thing you know, ZAP-SPARKS-YIKES!!!

[jp5Touring]

Thanks,  I do have a cover, I can't decide yet if its sufficient. Agree with the sparkes, yikes things happen scenario.

Will see how well the cover holds up.  

The fuel line setup is what came with my car. I had the 40 duel Webers rebuilt and tuned when I purchased the car.

Mechanic added the fuel regulator since their was none. Webers are at around 90%,95%.  still need a little tweeking.

The linkage is tired and plan to update over the winter,maybe with the four to one intake instead of my two 2 to 1 intake.

I like the idea of four to one better so far,will research that.  I also have a tii fuel tank,in a non tii car. Added the fuel line check valve to the IE electric pump and filter.  Agree to run fuel line along the  fire wall.  If someone sees  concerns  or something that could be improved please let me know. One question would I need a return fuel line to gas tank with this set up ?

 

[AustrianVespaGuy]

Ok, so I'm firstly going to refer you to this concurrent discussion regarding the return line for your reading pleasure:

 

Now with that said, the short answer of my personal opinion is:

1.) Since you're running an electric pump, continue to use the external steel line for the supply, but clean up the ugly routing in the engine bay, as we previously discussed.

2.) Sidedraft Webers in particular are quite sensitive to the level of fuel in the bowls, as this regulates the fuel pressure supplied to the jets.  Putting in the fuel pressure regulator was therefore very smart to help keep this consistent.  With the regulator, a return probably isn't necessary, but it would do some good things like help make sure neither that regulator, the fuel pump, nor the float needle seat need to work extra-hard trying to hold back the flow of unneeded fuel.

3.) Since you have an electric pump, a smart idea with regard to safety (and I can't tell from you pics if you already have this) is to use an oil pressure driven or inertial switch that will cut power to the fuel pump in the event of an accident.  Just like battery sparks, continuing to dump raw fuel into an area where there could be open flames is generally considered undesirable.