BURR2OF4

I was on my way to work this morning in my 1980 pickup and i noticed my charge lite was on. i was already committed and tried to make it to work but my truck died about half way there. i knew by battery was dead because my lights were barley visible when the engine died. i opened the hood and inspected the alternator, (i have a chevy 3 wire alternator in my truck). I noticed the nut on the back of the alternator was a tad bit loose so i snugged it up with a wrench and asked someone to jump start me. when we hooked up the cables my engine started turning over very slowly 1 revolution at a time and i had the keys in my had and the ignition was in the off position. i pulled the exciter wire from the starter and it continued to turn over. thats when i disconnected the jumper cables from my battery and they were very warm, almost hot. what would cause my starter to turn over on its own when trying to jump start it.
Thanks for any help

83pingpong

Bad solenoid. Likely solenoid is stuck "ON". It is on the side of the starter.

Nothing real easy about starter removal, but If it tries to turn over without the key, the solenoid is thrown. Could also be a shorted ignition switch. You could try disconnecting the ignition switch and see if the problem persists. If it does... solenoid. I guess the thing I am calling solenoid is the plunger? That true swampfox?

83

Do you really mean it when you say "nothing real easy about starter removal"?

I've found it to be one of the easier things to do on my truck, just a bit worse than changing the oil.

swampfox

The starter plunger probably welded it self to the contacts. If you are lucky it may be as simple cleaning the contacts and plunger, with a file or sand paper.

RAD4Runner

I believe by "exciter" you mean this (control wire for starter solenoid)?


If yes, solenoid plunger is likely stuck in "actuated position", keeping contacts closed, OR contacts welded closed

No need to disconnect ignition switch because he already disconnected solenoid control wire ^^^

Concur.

BURR2OF4

if this is the case why does it only happen when jump starting? when i put a fully charged battery in the truck it started normally?

RAD4Runner

You still haven't answered question aboujt "exciter^^^.
MOre questions... It still does it even when you "pulled the exciter wire from the starter" while jump starting, but not with a fully charged battery? And with that supposedly fully-charged battery you are able to start normally?

83pingpong

Based on your original post, it sounds like the 'dead' battery may have a short. It even drains the jump starting battery! So I think you have TWO PROBLEMS. The battery needs to be replaced, and your starter plunger is stuck "on".

If you had been running it with the plunger stuck on the way to work when it died, you may need a new starter and battery AND a flywheel if it got damaged with starter engaged while driving,

If the starter plunger was stuck, it was constantly draining the battery, but also grinding the flywheel with the starter gear! Your battery might recover, but at this point, you need to inspect the flywheel. If you install a new starter with a damaged flywheel, it will damage your new starter.

BURR2OF4

yes yes and yes. i installed a new alternator today but i havent hooked up the wires yet because i have a weird problem. one of the wire hooked up to the positive terminal on my battery has continuity with the vehicle frame. i traced it to the ignition switch and thats where things get weird. on the back of the ignition switch with the key off only the black with the yellow stripe has continuity. if i turn the key on i get continuity to the blue wire with the red strip and the black wire with the red stripe as well as the black w yellow

BURR2OF4

also i forgot to mention that when i unplugged my ignition switch i noticed that the switch has 5 wires but the pigtail it plugs into only has 4 wires. its missing the plain black one in the middle

83pingpong

Isn't the exciter wire direct from the ignition switch?... NO, ACTUALLY FROM THE RELAY! But..that relay wire going to the solenoid should be a 12V switched line that only gets power when ignition is turned to the start position (starter engaged). There should be no power on the exciter if the ignition is in the on position (running, coil charged)... that's NOT powered unless in the start position (starter engaged). If you remove the igniter wire, and it still powers the starter, then the plunger must be stuck closed (in contact, and starter ALWAYS powered by battery-bad situation).

The starter "bendix" or solenoid does two things... 1. Throws the pinion gear into the flywheel, and 2. connects the battery to the starter. There is a fat cable from the battery positive post on the battery to the solenoid. If the exciter wire to the solenoid is disconnected, and the starter attempts to turn when the battery is connected, the solenoid is tripped and stuck in the on position.

As I said before, if this is what's happening, and you drove it that way, the pinion gear was probably on the flywheel. If you revved past 1500 rpm while driving, that's WAY faster than the starter should turn. If this is what happened, you probably need a new starter, and you may need a new flywheel.

Test- if you remove the wire to the solenoid (what you are calling the "exciter wire"?), and connect a good battery-if the starter makes any noise at all, it is probably the plunger fused in contact. If this is the case, you'll probably need a new starter now (if you drove it while starter engaged), and you need to inspect the flywheel gears.

If the flywheel has damage, a new starter will get damage to the pinion gear every time you start it.

If the starter was engaged constantly, the battery would get drained, and the wire to the starter would get HOT. This might seem to cause a "dead" battery. The battery might recover if you solve the problem. Check the fat wire to the starter, melted insulation? Browned?

BURR2OF4

correct. except the problem only presents its self when jump starting. it did it again yesterday. i was at pick n pull and when i went to start my truck to leave it wouldnt start.i tried to have someone jump start me and it did the same thing it did when i was on my way to work. i went back inside and bought a used battery and held it upside down onto my battery while my buddy turned the key and the truck started.

83pingpong

I added a lot to my previous post. BTW, I am wrong about direct to ignition switch-I forgot about the starter relay, but that wire from the relay is only powered when ignition is turned to Start position. You can verify this with a light bulb or voltmeter. But the real question..You need to verify if the starter DISengages reliably...

Your post title is

starter spins without turning key when trying to jump start

And yet, you say your buddy had to go turn the key while you "held the battery upside down" on your battery (jumpstart).

Which is true.. Starter spins without turning key? or buddy had to turn the key ??

BURR2OF4

the starter only turns without the key when im trying to jump start it with another vehicle using cheap undersized jumper cables. and when it does this it turns verry slowly. like maybe 2 revolutions per second. when i used the other battery upside down i told him to hit the key as soon as i had the posts touching because i didnt want to take the chance of spilling any more water than i had to.

83pingpong

sulfuric acid/lead sulfate, not water. Careful there!


So it always turns over if you connect a battery, even without turning the key. Is this true even with the wire on the solenoid disconnected? That is the wire from the starter relay to the starter solenoid or plunger. If it turns over even with that wire disconnected, then the starter is remaining engaged when it is running (plunger stuck).

BEFORE you screw around trying to figure out that "spare" lead on the starter connector, Do these simple tests to see if the starter is getting the right power, at the right places. Much easier, and you will actually have a clue when you are done.

1. Disconnect the big red wire that goes to the starter from the battery.
2. Turn the key on (not to start position-just on)
3. Check to see if the wire from the starter relay to the starter has power (with key on).

If there is no power to the switched wire from the starter relay to the starter solenoid (the "exciter wire) with key in the on position, that is normal.

Then check to see if there is power at that same wire when you turn the key to the start position-that is normal.


If these things are normal, leave the exciter wire off, disconnect the battery, reconnect the big red wire to the starter, and if the starter makes any noise when you reattach the battery, your plunger is engaged when it should not be.

RAD4Runner

Your truck is hurtin' and now you're trying to hurt yourself? WTF?

Co_94_PU

iTrader: (-1)

The vents should be closed unless it's over-heating/worked, but I wouldn't recommend tipping a battery if it can be avoided.

That missing wire from your ignition plug is likely you problem you'll need to track that down, it's tied to power somewhere most likely. Once you get the wiring sorted out you can fix the boundup/engaged starter issue.

BURR2OF4

the morning that i broke down on my way to work i pulled the small control wire from the starter solenoid while the starter was spinning and it continued to spin at the same speed. since then i have removed that starter and bolted in a new one but i havent connected the wires yet because i think i still have a major problem. i think i have a bad ignition switch but i dont know for sure. its a 55 dollar part and i dont wanna go but a new one unless im sure i need it. ive done the tests you outlined and the only thing that seems out of the norm is the wire going from my battery to the ignition switch having continuity with the truck frame.

83pingpong

If a wire going from your battery to anything shows 0 ohms to truck frame, don't connect it to the battery positive post. If it ever was connected to the positive post of the battery, the insulation would be melted off. You must be mistaken. Does that wire connected to the battery also have the fat red wire that goes to the starter? Or is it the black (or black/yellow) connected to the body??

BURR2OF4

im not sure if i completely understand your question. besides the big heavy gauge cable that goes to the starter motor there are 3 extra wire coming off the positive post. one is plain white and it goes to a plug that is not being used. i think it was for the original radio but i could be wrong. the second one is black w red and it goes to the ignition switch. the third on is red w green and it goes to my light switches. the starter control wire is black w white