Misfires

dts3 · 11-12-2018, 08:47 AM

What is making you call it a low voltage condition? If your alternator is on it's way out, I'm curious if maybe it actually caused a voltage spike that blew your starter motor. If this is what happened, anything that's got a 12v line is in theory fair game. In the lab, we've ESD'd circuit boards that have failed in such a way that makes it hard to figure out what has happened. They would half-way work, but do all kinds of crazy ****. We had one case where a voltage spike killed a capacitor on a circuit board, but it failed closed (causing a short). This in turn caused it to destroy any other electronic hardware that it was plugged in to... almost like a hardware (as opposed to software) computer virus. I mention all of this to point out that transient voltage spikes can ruin things in very unexpected ways. Hopefully it can be diagnosed without spending money replacing many things.

JSur · 11-12-2018, 09:00 AM

Quote:

Originally Posted by dts3

What is making you call it a low voltage condition? If your alternator is on it's way out, I'm curious if maybe it actually caused a voltage spike that blew your starter motor. If this is what happened, anything that's got a 12v line is in theory fair game. In the lab, we've ESD'd circuit boards that have failed in such a way that makes it hard to figure out what has happened. They would half-way work, but do all kinds of crazy ****. We had one case where a voltage spike killed a capacitor on a circuit board, but it failed closed (causing a short). This in turn caused it to destroy any other electronic hardware that it was plugged in to... almost like a hardware (as opposed to software) computer virus. I mention all of this to point out that transient voltage spikes can ruin things in very unexpected ways. Hopefully it can be diagnosed without spending money replacing many things.

I don’t think it’s all tied to low voltage but the symptoms significantly decreased when I threw in a new battery. I believe the low voltage is just a product of the starter and/or alternator slowly going bad over time. The cars creeping up on 90k, has been boosted for over 30k, as well as a bunch of accessories that require lots of power. I’ve been told that a bad starter solenoid can cause a power draw. I’m hoping that by replacing those two parts it’ll, ideally, solve the power draw mystery, or at least bring me back up to par so I can properly track down the issue.

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11-12-2018, 08:47 AM	#1 (permalink)
dts3 Track Member Join Date: May 2018 Location: Farmington Hills, MI Posts: 599 Drives: 08 Expedition Rep Power: 6766	What is making you call it a low voltage condition? If your alternator is on it's way out, I'm curious if maybe it actually caused a voltage spike that blew your starter motor. If this is what happened, anything that's got a 12v line is in theory fair game. In the lab, we've ESD'd circuit boards that have failed in such a way that makes it hard to figure out what has happened. They would half-way work, but do all kinds of crazy ****. We had one case where a voltage spike killed a capacitor on a circuit board, but it failed closed (causing a short). This in turn caused it to destroy any other electronic hardware that it was plugged in to... almost like a hardware (as opposed to software) computer virus. I mention all of this to point out that transient voltage spikes can ruin things in very unexpected ways. Hopefully it can be diagnosed without spending money replacing many things. JSur likes this.