So first background on the car: 1987 BMW 3-series with a 347 SBF, trunk mounted battery, "old style" starter. I experience a good deal of heat soak in the starter after running on track, so I'm replacing it with a mini-starter to hopefully fix that problem and also save some weight. Traditionally the mini-starters are wired this way:
![Image]()
I would prefer not to have my 00 gauge battery cable from trunk to starter hot all the time. Judging by the 10-12 gauge wire that's recommended for the mini-starter's solenoid, I'm assuming it pulls some decent amps and is why it's not simply triggered off the ignition switch. So, what if I left my main battery cable as it is (keeping the long run cold when not cranking) and simply added a relay off the ignition switch with a fused 10ga wire? I'm I missing anything as to why this won't work? Here's a simplified drawing of what I'm thinking:
![Image]()
I would prefer not to have my 00 gauge battery cable from trunk to starter hot all the time. Judging by the 10-12 gauge wire that's recommended for the mini-starter's solenoid, I'm assuming it pulls some decent amps and is why it's not simply triggered off the ignition switch. So, what if I left my main battery cable as it is (keeping the long run cold when not cranking) and simply added a relay off the ignition switch with a fused 10ga wire? I'm I missing anything as to why this won't work? Here's a simplified drawing of what I'm thinking:
