kramttocs Posted August 25, 2020 Share Posted August 25, 2020 Function to power relay pull-in coil... to ground, hot from battery. Ground relay: hot coil to ground through the speed switch, motor to battery ground (or some substantial ground near the motor. Yep, that's how I think I did the ground relay, and how I plan to do the power relay - with the exception that power will be from a fuse in the PDB and then from the battery. As for providing source, sink, etc, we'll get official schematics when we conclude. But I was just answering Scott's question of where I put the ground relay and thought I might as well show where I want to put the power relay. With such a drastic change in the amps going through the factory fuse box, what is the general thought on dropping the fuse rating? My fuse buddy circuit testers came in the other day so I was, primarily out of curiosity, going around and seeing what everything was pulling. Not surprisingly, with going to all led besides headlights, headlight relay mod, and this blower mod, all of the factory fuse sizes are way beyond the draw now. For the blower fuse it was around .10 amps no matter what speed. Expected since it's just pulling in a relay. When A/C is on and compressor engaged, since it goes through the same fuse, along with the fan it was around 4.6 amps fluctuating but never going over 5. I know you fuse for the wire but is there any reason to not reduce this fuse to a 10 instead of the 30? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 25, 2020 Share Posted August 25, 2020 With such a drastic change in the amps going through the factory fuse box, what is the general thought on dropping the fuse rating? My fuse buddy circuit testers came in the other day so I was, primarily out of curiosity, going around and seeing what everything was pulling. Not surprisingly, with going to all led besides headlights, headlight relay mod, and this blower mod, all of the factory fuse sizes are way beyond the draw now. For the blower fuse it was around .10 amps no matter what speed. Expected since it's just pulling in a relay. When A/C is on and compressor engaged, since it goes through the same fuse, along with the fan it was around 4.6 amps fluctuating but never going over 5. I know you fuse for the wire but is there any reason to not reduce this fuse to a 10 instead of the 30? We had this "conversation" when you convinced me to put a 3a fuse in my PDB to run the voltmeter. So, why are you doubting yourself now? Seriously though, I see no reason not to reduce the size of the fuse as that will ensure the fuse blows quickly before any damage can be done should there be a fault. Presumably you'll be carrying spares? Link to comment Share on other sites More sharing options...
kramttocs Posted August 25, 2020 Share Posted August 25, 2020 We had this "conversation" when you convinced me to put a 3a fuse in my PDB to run the voltmeter. So, why are you doubting yourself now? Seriously though, I see no reason not to reduce the size of the fuse as that will ensure the fuse blows quickly before any damage can be done should there be a fault. Presumably you'll be carrying spares? Haha that's right! I felt like I'd had the discussion before I'd actually been changing them all out to pretty much 5's and 10's but then I got to wondering last night if there was any reason I shouldn't. I would say that me telling you that and you telling me that I told you that as well as now you telling me that it's ok is good enough for me. Even though the 30a fuse for the blower was just relocated, it does feel good to drop the in-cab one down significantly. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 25, 2020 Share Posted August 25, 2020 I would say that me telling you that and you telling me that I told you that as well as now you telling me that it's ok is good enough for me. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 25, 2020 Share Posted August 25, 2020 With such a drastic change in the amps going through the factory fuse box, what is the general thought on dropping the fuse rating? My fuse buddy circuit testers came in the other day so I was, primarily out of curiosity, going around and seeing what everything was pulling. Not surprisingly, with going to all led besides headlights, headlight relay mod, and this blower mod, all of the factory fuse sizes are way beyond the draw now. For the blower fuse it was around .10 amps no matter what speed. Expected since it's just pulling in a relay. When A/C is on and compressor engaged, since it goes through the same fuse, along with the fan it was around 4.6 amps fluctuating but never going over 5. I know you fuse for the wire but is there any reason to not reduce this fuse to a 10 instead of the 30? If that's how y'all feel. Fuses are sized to protect the harness. Harnii are sized for the components connected. I hear you that LED's and add on relays reduce the need to flow a bunch of current through the ignition switch and fuse panel. I don't have any intention of undersizing my fuses unless I chop out a section of existing harness, and deliberately under size it. Link to comment Share on other sites More sharing options...
kramttocs Posted August 25, 2020 Share Posted August 25, 2020 If that's how y'all feel. Fuses are sized to protect the harness. Harnii are sized for the components connected. I hear you that LED's and add on relays reduce the need to flow a bunch of current through the ignition switch and fuse panel. I don't have any intention of undersizing my fuses unless I chop out a section of existing harness, and deliberately under size it. I think that's an entirely valid stance. I will still do so but acknowledge it doesn't really benefit anything. Link to comment Share on other sites More sharing options...
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