Positive Battery Cable Extension

So I was switching out the OEM terminal on the positive cable to better suit the Blue Sea setup with heartier terminals and I would have sworn that the positive main cable was long enough to cut the terminal right at the base and get it into the other terminal on the stock battery. Turns out, it's not.

Anyone have any suggestions for extending this cable a few inches? I found some battery splice repair kits at the local auto shops but they were for 4 gauge maximum and the stock positive cable appears to be at least 2 gauge. I'm trying to avoid having to run completely new cable and pull everything out of the loom etc. if possible. All suggestions are welcome...

 

I made a little 6" extension with some extra 1/0 and 2 ring terminals I had laying around.

 

How did you connect the 1/0 to the oem stuff exactly?

 

I used a small 3/4" or 1" copper nut and bolt. And bolted the extender to the stock wiring from the starter and fuse box. I think I had to grind off a portion of the stock positive cable terminal from the starter and straighten out a section of it to make what amounted to a square ring terminal.

If you wanted to you could cut the stock terminal off and solder on new terminals. The 6 inch extender I made leaves plenty of room to clip the existing terminal.

 

Just buy a longer cable. They aren't that expensive.

 

As in route the entire cable? I'm less concerned with price and more concerned with tearing the entire wiring look apart to run that cable haha

 

Yep. Even if you have the equipment to properly crimp the cable (which is highly unlikely) it won't be as good as an unbroken connection. Soldering is the last resort and that isn't as good, even when done correctly, long term as a proper crimp. So bite the bullet and dig in. Not dealing with speaker wire or a five amp accessory here.

 

Have you happened to have done that before? Don't want to get in there and start messing up even more stuff

 

If I understand you you need to have a longer cable for the starter lead ( the big one ). It only goes between the battery to the starter. Not very involved at all.

 

Another option is to try a specialized electrical/battery place. I worked at one and we made custom battery cables. Have them make a short extension 2 gauge cable that you need using a soldered splice- take home and with a propane torch solder onto your piece. make sure they give the necessary piece of heavy duty heat shrink and you will be fine. Hardest part seems trying to find someone that still does this.

 

Yes. I have completely built and rebuilt vehicles and just changed cables but never on my Tacoma or a vehicle this new. Its been many years but old or new they should all be pretty much the same. So in general you should have one heavy and one thinner cable (Maybe a second thinner one too). The big one runs in a loom and connects to the starter and should connect with a bolted lug. Just disconnect the loom supports, cut the tape and strip the battery cable out of of the split loom so you can see what you have. If you find a second thin cable in the loom that also comes off the positive via a wye connector just trace that one to its connection point and see what you have. The other small lead connects to the fuse and relay block. Be sure to buy the replacement cable before you unbolt anything. All replacements should have a complete thick high amp cable for the starter. Some of them will have a complete thinner fuse block (and other if it exists) cable with ends or they may just provide a pig tail and splice connector. I could go out to the garage and take a look at mine to see what is there but you should be able to do the same to confirm the info above is accurate. The biggest problem should be getting your hands in the tight spaces to undo and retape the loom.

 

Thanks for all the help everyone, I ended up getting some 2 gauge cut to length and built a new positive lead from the starter to the battery. Not very involved at all just a bit of a pain reaching around the strut housing to get to a plastic clip thing. If anyone has any questions on this in the future feel free to PM me.

 

Pics?

 

What was the original length vs final length?

 

Sorry for the delay, here are the photos.

This is just an overview of the setup I did, the actual blue sea panel is in the back.


This one shows the first plastic clip that holds the wiring loom in place. You can use a flathead to get it off the mount and then again on the harness itself to unlock it so you can reuse it later.



Better photo of the same clip.



This is a really hard to see photo but the thing is in an awful spot. It's directly behind the housing for the strut on the driver's side. I jacked it up and took the drivers side front tire off as well as the splash guard stuff. That helped a lot but it was still a pain. It's attached to its mount in two places, then there are two or 3 tabs to unlock the actual harness itself. A lot of different wiring all comes together here so be careful with this one.



Lastly there is this section of wire that has heat shielding on it to protect it from the exhaust manifolds. you can peel this stuff off and reuse it. The cable connects to the starter with a terminal but I cut it off and used my own simple 3/8" eye terminal and it's working fine.



You can go to a Napa and they will build the actual wire for you, soldering the terminals on and heat shrinking it and everything. Or you can do it yourself. 3/8" eye lugs with work fine. I got some solder and flux little pucks and you can just set them in the lug upside down, heat it up with a torch and then just stick the wire straight down into your little puddle of solder and that stuff won't go anywhere. Another thing to note is that it appears like the stock wiring is 2 gauge but the insulation was sort of smaller than standard 2 gauge. So you'll want at least 2 gauge but the wire will be bigger than stock and you might have to wrestle with it to get it all back into the stock harnesses and attachment points. I got 36 inches of cable and that left what you see in the first photo. Some slack but nothing too much. If you have any questions let me know.

 

Looks good thanks. Been wanting to upgrade my battery cables for my new battery, already got nice new terminals too.

 

@I3uller "You can go to a Napa and they will build the actual wire for you, soldering the terminals on and heat shrinking it and everything."

That's a great tip, would not have known that , thanks!!

 

Thanks for the post; this helped me rerun both my positive cables on my 2007 4.0L Tacoma after I replaced the alternator. It took me several hours to get the positive cable all the way down to the starter and reconnect all the cable housings. I had to bypass the long connector attached to the alternator since I spent an hour trying to open it with no luck. I also replaced the cable to the fuse/relay box since that one was corroded.

I finally got everything back in place and tried starting it up and now the starter doesn't even click. Lights dim and I hear some type of noise but no click. Brand new battery, brand new alternator, new terminals, good signal from starter positive and starter ground to battery. I used heavy marine grade 2ga wire on the starter main. I don't read any short between starter contacts. I just took the positive connection off, cleaned everything with a wire brush and then with some deoxIT contact cleaner, that did not improve the situation.

Any idea what could be wrong? It seems like a connection issue. The only strange thing I noticed is that there felt like a little bit of play when loosening the alt bolt. It would turn about 1/8 before feeling like it was engaging the threads. Could I have cracked a connection inside?

Thanks,
Ian

 

Sounds like something is grounded when you turn the key. I would double triple check everything. It sounds like you have something connected wrong.

 

Thanks for the diagram, I think some of my initial observation was wrong though. I did notice the solenoid is clicking once when turning the key.

I swapped back the original + to fuse box cable, cleaned off the ground connections by the battery some more, tried to start it, didn't help. I charged up the battery, re-crimped the engine ground connector by the battery, gave the starter a little tap with a wrench, then it started on the second try! I tried about 10 more starts and it would turn over 1/3 times. I'm definitely not satisfied.

The only other connection that could be causing a problem is the engine to negative. I replaced the connector with a simple copper crimp connection but I think it was meant for 4ga, not 2ga. I managed to squeeze most of the wires in but there were maybe 3-4 strands that didn't make it. I will try replacing that next...

If that doesn't help, I'm wondering if the ground to engine connection was damaged. My DMM doesn't read well below 0.5 ohm so it's hard to check.