15 September 2016

Smoke From The Starter

Replaced the battery.

Car cranked fine a couple of times, but once the voltage was way too low.

I measured the voltage from the alternator and it was super low.

So I shut off the car, double checked the connections and fired it back up.

Voltage seemed better, but when I went to check at the alternator, I smelled wiring burning.

I finally found some smoke coming off one the connections near the starter solenoid.

Eureka!

On my Vette the positive lead goes from the battery in two branches.  One goes to the underhood fuse and power distribution center, the other goes to the starter and then to the alternator.

If something is shorted in the starter, it's not going to be able to charge!

There goes another $155 plus tax on a starter and exhaust gasket.  I get some of it back from a core charge though!

The battery cables are in rough shape.  Even if they aren't causing problems, they will soon enough.

The battery might be OK, but probably not.

The starter is sick and because it's daisy chained into the charging system, and that's where the smoke was, that's prolly the problem.

Update:

Yup, that's the problem!


3 comments:

  1. Let me make sure I understand something. You said, "On my Vette the positive lead goes from the battery in two branches. One goes to the underhood fuse and power distribution center, the other goes to the starter and then to the alternator."

    I read that as the wire (which at this point is about the diameter of your finger or thumb) leaves the positive terminal and divides in two wires of smaller diameter or has a splice of the same size. One side is fused and the other isn't fused at all?

    If that's the case, you're lucky that's all that happened. Should that solenoid develop a hard short to ground, that's a direct connection to the battery and that battery will deliver enough current to melt that wire. Red hot, dripping, molten copper. Bad Things will happen, up to and including setting fire to the car and everything near it.

    Is that right?

    ReplyDelete
    Replies
    1. What you are looking at in the starter picture is the "fuse" blowing, such as it is. Every time I've seen a solenoid hard ground, the solenoid comes apart before the fire starts. The bakelite like material on the back of the thing turns all powdery when the wiring gets hot enough, before it goes molten. It's probably amazing I could still start it!

      The back of the starter has a fuseable link, but that won't help if the solenoid grounds.

      I've seen cars where that fire happened though!. As you say, "bad things". Old Mopars seemed particularly vulnerable once the owners had "fixed" the fuseable links that were merely doing their intended job.

      However, I've been wrenching on hot rods for decades and a wire straight from the battery to the back of the starter solenoid is the norm. I guess we should be amazed more fires don't happen!

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