My ‘91 N/A rx7 has worn battery terminals and the long positive and negative cables that connect to the engine and alternator. The shop quoted $450 just to remove the cables and another $1,000 to custom fabricate new ones because none of their vendors have any in stock. I found cables that fit an S5 turbo model but I’m not sure if they’ll work with the N/A. How can I solve this without cleaning out my savings account?

 

That sounds absolutely ridiculous honestly. Gives me the impression that would make me recommend to not go to that shop ever again...

I'm from europe so I don't know where to look exactly but you should be able to get battery cables, terminals and battery terminals at any auto shop or specialized (automotive) wiring shop.

Not sure how much cable you intend to replace but from battery to alternator and starter isn't that crazy...

 

You can buy premade battery cables from McMaster-Carr that are pretty good, but they may not be the best length - could always buy the longest length, cut to size, then only need to replace the lug terminal to ground or go to the starter. I can't imagine there is any appreciable difference in length on the N/A and Turbo cables.

Do the cables themselves need to be replaced or could you just put new terminals on the ones that are there? You can also make your own with the correct tooling and terminals - and for way less than $1,450.

 

I can't say 100% as I haven't done it but I'd be almost 99.9% sure those S5 TII cables can be made to work or may even work with no modification at all..

 

Amazon is loaded with cable for your car battery. Cut to length, install your hardware and you are good to go.

 

DIY Option - Make your own custom cables. For that you'll need to buy or rent a crimper to crimp the lugs on each cable end, something cheap like this will do it: https://www.harborfreight.com/hydrau...ble+crimp+tool

Then you'll need the appropriate length of battery cable in the right gauge sizes, some lug terminals (sized for the cable and studs they are going over), and a set of marine battery terminals. Some examples of the lugs & marine battery terminals below:

https://www.terminalmart.com/2-ga-ba...SABEgJXZvD_BwE

https://www.autozone.com/batteries-s...E&gclsrc=aw.ds

Then you just build the cables with an appropriately sized lug at each end to bolt to the marine battery terminals, and the starter motor/ground points at each end

 

Normally I don't go into this, and I'm gonna bend a forum rule about language for the sake of clarity, but holy jumping f*cking sh*tballs. If that's not a "f*ck you, bugger off" price, then I don't know what is. Either that or they have a problem with certain substances. Maybe both

This is literally a 2 hour job (at most) with off-the-shelf stuff from Walmart or Autozone and easily performed on two jack stands. You'll need Marine Battery terminals and 3 pre-made cables, two 24" ones and one 48" or 51" (either is fine), all 4 gauge with two lug terminal ends. The 48/51" cable will be the positive to the starter, one 24" is Battery Negative to Body Ground, the other is Body Ground to Starter Negative (one of the mounting bolts). The "worst" part of this entire job is unwrapping the harness to separate the cables from it, and that's more tedious/boring than difficult as it is just unwinding electrical tape. Unwind an inch or two, pull the cables to the side, re-bundle the remaining harness with fresh tape. Repeat until you can remove the cables entirely.

Follow this guide, it works.
https://www.aaroncake.net/RX-7/grounding.htm

The only modifications I would suggest is to use a 20 or 25mm long stainless steel M6 bolt for the Body Ground and put it in from the Wheel side. It makes reassembly MUCH easier since it effectively becomes a stud to hook the ground cables onto. Last, for the fuse box/alternator cables, crimp on one ring terminal per cable. The common Yellow 10-12 gauge ones will work on a single 8awg cable with a little persuasion. Plop the Marine Battery Terminals on the battery, reconnect everything and enjoy.

 

Tractor Supply has a good source of decent pre-made battery cables.