Enclave Weak Start Issue


New member
2010 Enclave
I am wondering if anyone can help with some diagnosis. I have a consistent weak crank and longer cranks than should be necessary to turn the engine over. Battery is 3 years old, is getting the 14.5 volts during charging and under the standard voltage drop test using a camera to watch the volt meter during cranking the engine, the battery voltage drops to 10.5v, which is in accordance with GM specs. Its never not started, just seems like it won't any day now.

I took the car to an old school battery repair/replacement shop and the old timer performed the following test with the following results.

1 Disconnect the battery (in the 2nd row under the floor) and load tested it with his box. Result is 800 amps available at the battery
2 Reconnected the battery and load tested the positive post and ground post under the hood. Result is 400 amps available under the hood
3 Load tested positive post and neg to frame/chassis. Result 400 amps
4 Old timer says go home and try step 5
5 Connected jumper cables from the battery to the under hood positive and neg posts and cranked the engine to see if direct ground and power to battery would isolate any chassis wiring or harness corrosion. Result is same weak start. I don't have a load tester but it is consistently weak so assumed less than 800amps
6 Not sure whats next except maybe jumper cables directly to the starter but that doesn't seem to explain why the available amperage in the battery wont transfer to the under hood contact points even with a stunt in there.

Car doesn't show visible signs of corrosion anywhere but it seems like there is something in there causing the reduction.

Any ideas would be appreciated.

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