Desert Rat
Well Known Member
Scott Hersha has a thread on here re; a midi fuse tp protect the alternator b lead.
Didn't want to hijack his thread, but it got me thinking;
Looks like most people put their B-lead current limit solutions on or near the firewall, if they bother to install one at all.
What exactly are we trying to protect here? If the b-lead is shorted out, it seems to me that it's more likely to be up under the engine somewhere. If that's the case, doesn't a firewall located limiter only prevents the battery from dumping too many angry amps into the short? It does nothing to prevent the alternator from happily melting the wire where the problem is more likely to actually be, i.e. between the alternator and the firewall.
In a perfect world, shouldn't the B-lead fuse/breaker/whatever be as close to the alternator as possible, in order to protect more of that fat wire as it snakes back to the firewall? Am I fundamentally wrong is some way that I'm not seeing?
I guess all this rambling leads me to 3 questions;
1. How much protection is a firewall mounted B-lead fuse actually affording a system? Especially if you already have a ANL fuse between your Batt contractor and precious firewall aft stuff.
2. If the answer to #1 is "not much" is it even worth considering installing one?
3. If I decide to press ahead and install one anyway, is there such a thing as an inline midi fuse that could be installed closer to the alternator, or is that just introducing a failure point with not much return?
As always, all opinions welcome.
Didn't want to hijack his thread, but it got me thinking;
Looks like most people put their B-lead current limit solutions on or near the firewall, if they bother to install one at all.
What exactly are we trying to protect here? If the b-lead is shorted out, it seems to me that it's more likely to be up under the engine somewhere. If that's the case, doesn't a firewall located limiter only prevents the battery from dumping too many angry amps into the short? It does nothing to prevent the alternator from happily melting the wire where the problem is more likely to actually be, i.e. between the alternator and the firewall.
In a perfect world, shouldn't the B-lead fuse/breaker/whatever be as close to the alternator as possible, in order to protect more of that fat wire as it snakes back to the firewall? Am I fundamentally wrong is some way that I'm not seeing?
I guess all this rambling leads me to 3 questions;
1. How much protection is a firewall mounted B-lead fuse actually affording a system? Especially if you already have a ANL fuse between your Batt contractor and precious firewall aft stuff.
2. If the answer to #1 is "not much" is it even worth considering installing one?
3. If I decide to press ahead and install one anyway, is there such a thing as an inline midi fuse that could be installed closer to the alternator, or is that just introducing a failure point with not much return?
As always, all opinions welcome.