Gro Harlem said:
The original link is long dead but here is a copy of it complete with pictures:
http://www.clubprotege.com/wil/howto/groundwire/
Now that I've read a bunch of these grounding kit articles, including the original, I'm becoming more and more dubious about the value of most of the grounding points that are employed. Assuming that the car's original grounding system is intact the only parts of the car that are likely to benefit from removing a few millivolts of ground noise are all electronic: some of the sensors, the ECU, and the stereo. (I'm thinking that if any of the sensors read by the ECU are that touchy then the leads betwen that sensor and the ECU probably need to be shielded as well, better grounding might not be good enough.) Things that won't care: the motor, parts belt driven by the motor, the manual transmission, all of the nonelectronic parts of the electrical system (the wires, switches, electrical motors, fuses and bulbs). This suggests that the key grounding points to address, if anything good is to happen at all, are on or near the sensors, ECU, and radio, and of course the primary ground near the battery. This is discussed most clearly here:
http://www.aaroncake.net/rx-7/grounding.htm
I found this a particularly good reference since it shows how to clean up the existing grounding connections, and explains why some of those might be degraded over time, at least on an RX7.
I'm also a bit leery of the wire and connectors people are using for these projects. The core doesn't matter much, 4AWG is 4AWG, but the insulation does matter, and most posts don't indicate any spec at all for the insulation. It should probably be SGX, SXL, or some other high temperature automotive engine compartment grade insulation. In fact, they (including most kit makers) don't say anything at all about the insulation. If the insulation melts, abrades, or fails in any way it might result in a ground to something that should not be grounded or greatly increased corrosion of the ground wires. As for the connectors, these really need to be attached better than the crimp used in normal electrical practice. What works around the house or office building is not necessarily going to hold up for long in an engine compartment, where it is subjected to constant vibration and extreme temperature variations.
