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Post by fredwinterburn on Jul 11, 2022 17:31:38 GMT -6
Actually it makes no sense to run a dedicated ground cable from the engine back to the battery. Under full starter load the maximum voltage drop through the car body and frame will be less than 0.01V which is considerably less than the copper supply cable from the + terminal forward to the engine block which most likely drops about 0.4V under full starter load (or less with a modern starter). I say this with some confidence as I have a 56 Morgan with the battery behind the seat (just in front of the differential) and I made these measurements on that car two months ago. Running a separate ground cable only makes sense on a boat made of fibreglass or some other insulating material. As long as the connections to the engine block/head and to the frame/body are sound, then running a dedicated negative battery cable is redundant. Other than the starter all other loads are too small to drop any significant voltage and the resistance can be considered to be zero ohms. Fred Sorry, the traffic on this forum is not anywhere where it used to be. I usually recommend the facebook page for the forum as it gets more views. That's if you're on facebook of course. I tried this kit on my first Aurora and noticed no change. I sometimes think things like these give the placebo effect to the people that undertake them. You spend the time and money doing it and your brain "wants" to feel like it achieved something. I couldn't verify any difference either in performance or overall stability of voltage. GM grounding from factory is usually "JUST" enough. And over time, corrosion and voltage drop from any and all causes can stack up, esp when the battery is far away(like aurora) I would say that improving the grounds by having additional from the engine to battery and the battery to sheet metal shouldnt hurt, but How much so it could help depends on how the system is doin The most important thing is to not cross a ground onto the same place the PCM ground is. Where ever the PCM grounds should oNLY be the PCM. and nothing should be run to it, near it, or cause it to be a ground path for something like a window motor |
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Post by AuroraGirlFromMars on Jul 16, 2022 6:50:39 GMT -6
Actually it makes no sense to run a dedicated ground cable from the engine back to the battery. Under full starter load the maximum voltage drop through the car body and frame will be less than 0.01V which is considerably less than the copper supply cable from the + terminal forward to the engine block which most likely drops about 0.4V under full starter load (or less with a modern starter). I say this with some confidence as I have a 56 Morgan with the battery behind the seat (just in front of the differential) and I made these measurements on that car two months ago. Running a separate ground cable only makes sense on a boat made of fibreglass or some other insulating material. As long as the connections to the engine block/head and to the frame/body are sound, then running a dedicated negative battery cable is redundant. Other than the starter all other loads are too small to drop any significant voltage and the resistance can be considered to be zero ohms. Fred GM grounding from factory is usually "JUST" enough. And over time, corrosion and voltage drop from any and all causes can stack up, esp when the battery is far away(like aurora) I would say that improving the grounds by having additional from the engine to battery and the battery to sheet metal shouldnt hurt, but How much so it could help depends on how the system is doin The most important thing is to not cross a ground onto the same place the PCM ground is. Where ever the PCM grounds should oNLY be the PCM. and nothing should be run to it, near it, or cause it to be a ground path for something like a window motor The redundancy is the point of adding grounds to a vehicle. Such as to an alternator case (plus keeping it good connection) |
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