tighe Posted February 17, 2020 Author Report Share Posted February 17, 2020 Small update. Yesterday I installed the negative cable from FCP, cleaned the terminal posts, and It started no problem. but, it had been starting no problem for the past week or so, so nothing conclusive there. The non starting an intermittent thing, so it’s been difficult to pin down. It’s can always be corrected by loosening the cable clamps and moving them around on the posts a bit. Today I went to fire it up and no start. Ugh. Moved the positive clamp around and it started. When I get a little more time I’ll be replacing that one as well. it’s worth noting that even when the car doesn’t start, there is still power- the lights and radio etc all work, but nothing other than a single click when I turn the key further. Will report back once the positive cable is installed. Link to comment Share on other sites More sharing options...
erikv11 Posted February 18, 2020 Report Share Posted February 18, 2020 On 2/10/2020 at 6:18 PM, tighe said: I was looking through some of my notes today and sure enough, when describing this issue to a mechanic friend of mine I described how the positive battery terminal got very hot after driving. Guess I forgot about that... Not sure what to conclude from this, but figured I'd get it written down here for posterity. Conclude that there is corrosion inside the cable, where it connects to the lug. That's why I suggested you check it. The corrosion causes the resistance to go up, which causes amps going through to go down and the wire to get hotter, which causes the resistance to go up more, etc. So when it's been driven for a while it can't pass enough amps for the starter (V = IR). The problem is the positive cable at the battery lug. Go ahead and install the POS, non-OEM part from FCP, it will be better than the corroded original one in there. That will fix it. Link to comment Share on other sites More sharing options...
tighe Posted February 18, 2020 Author Report Share Posted February 18, 2020 Awesome, thanks for the great explanation! Makes a lot of sense. I’ll get to replacing the positive...I’ll make it a priority now. Really appreciate the explanation. Link to comment Share on other sites More sharing options...
gdog Posted April 3, 2020 Report Share Posted April 3, 2020 Did you ever resolve this? Fairly simple to test for bad cables; do a voltage drop test across the suspect cable when under max load (during engine cranking). If voltage drop from one end of the cable to other approaches 12v, you found the problem. Should be closer to 0v. https://www.aa1car.com/library/voltage_drop_testing.htm Link to comment Share on other sites More sharing options...
tighe Posted April 3, 2020 Author Report Share Posted April 3, 2020 10 hours ago, gdog said: Did you ever resolve this? Fairly simple to test for bad cables; do a voltage drop test across the suspect cable when under max load (during engine cranking). If voltage drop from one end of the cable to other approaches 12v, you found the problem. Should be closer to 0v. https://www.aa1car.com/library/voltage_drop_testing.htm That's a good method, thanks for sharing. I replaced the negative cable with a brand new one a month about a month or so, and have not had any problems since. So I'm tentatively hoping/assuming that was the problem. I bought a new positive cable too; I'll install it when time permits or if the problem resumes. Or if a few more months go by without any issue maybe I'll send it back to FCP. Thanks to all for the troubleshooting suggestions! Link to comment Share on other sites More sharing options...
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