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Electrical issues

OP
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Glencoe
Thread Starter #21
alright just saying, left signal wire connected. Car was charging fine as mentioned, then after shutting it off it immediately started acting up again. was seeing 12.4 on the new battery. cabin lights flicker with hazards on too. I think this is related. Under no condition should the battery be charging this low. I'm really grasping at straws here but would be curious if others could take off their battery voltage sensor and measure resistance from ground to ground out of car. Tasca sells this part for 65 dollars and it would be the next easiest thing to check in the system. not sure if diagnosing by resistance is applicable for this part, but it wouldn't take long to measure and I'd really appreciate it if someone could just for comparison.


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koozy

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#22
why don't you post the resistance you've got that you're asking for and be clearer on how your measuring (what and where you're connecting probes to) so other's can do the same if they choose to help. photos would be good.
 


dmb

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#23
If it would make you feel better clean your grounds, both sides and clean them even if they look clean, and if you want run a ground wire from the engine to the body. bad grounds cause all kinds of weird things. nuff said.
 


Intuit

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#24
12.4 isn't too far off from 12.6v. IIRC it should maintain at least 10.1 or 10.5v during crank. (hold the accelerator pedal to the floor before and during crank to prevent start) Are you familiar with the concept of "Voltage Drop Testing"? Do whatever you can to place maximum load between two points on the same wire, then measure its leakage. Prior car was overcharging and frying alternators in a matter of minutes because of weak grounding between the engine alternator and battery. Voltage drop testing allowed me to confirm the cause and test out a resolution. IIRC the voltage drop amount was "only" 1.65 volts. After adding some additional grounding it was down to 0.03v with all accessories running and at higher RPM.
 


LaserWhisperer

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#25
I believe the PCM controls this. I couldn't guess as to specifically what is causing your issue, however. Here's the charging system wiring diagram:

alright just saying, left signal wire connected. Car was charging fine as mentioned, then after shutting it off it immediately started acting up again. was seeing 12.4 on the new battery. cabin lights flicker with hazards on too. I think this is related. Under no condition should the battery be charging this low. I'm really grasping at straws here but would be curious if others could take off their battery voltage sensor and measure resistance from ground to ground out of car. Tasca sells this part for 65 dollars and it would be the next easiest thing to check in the system. not sure if diagnosing by resistance is applicable for this part, but it wouldn't take long to measure and I'd really appreciate it if someone could just for comparison.


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Augie, check the inline fuse in the schematic that Krug posted (3A).
It's located on the battery positive terminal block.
Mine was blown due to corrosion (shitty OEM battery leaking) and caused some electrical issues.
I repaired it and replaced the battery and everything went away
 


OP
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Glencoe
Thread Starter #26
The fuse is good. Krug ohm'd out his battery voltage sensor (on negative terminal) for me. compared readings. Our measurements were very similar across one prong but mine constantly fluctuated on the other (his settled at 1.5 mohm). could be other factors at play here but its a cheap part and I will replace and report back. I've done a voltage drop test (on my bad battery even) and everything always stayed above 10


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OP
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Thread Starter #27
fuse isnt blown. at least as of me checking it a few months prior. just ordered a new BMS from tasca tonight, about 70 dollars shipped


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koozy

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#28
My car is sitting without the battery in the car as I’m working on things. I could have easily ran some test in response to your request had you answered my questions above. Instead you choose to throw parts at it, LOL


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