[Ice]

Hi,

I just tried to start my Forester 98 on a weak battery. After a few turns of the starter I heard a poof! and it went all dead. After I had turned off the ignition and taken out the key I heard the starter take another turn (!) When I tried to charge the battery I realized that it now was shorted, only around 2k ohms resistance between the positive pole and ground.

Any smart guys here with ideas for what I should start looking at?

Ty

 

[Majorlk]

A new battery ...

 

[Ice]

Sometimes the obvious is hard to see. It looks like the "short cut" is in the battery itself.

Consider your daily good deed completed. Thanks!

 

[bbottomley]

I'm surprised that there wasn't enough residual energy left in the battery to blow out your ohmmeter. They don't tend to like being used on live circuits.

 

[ryanlarue]

Hi,

I just tried to start my Forester 98 on a weak battery. After a few turns of the starter I heard a poof! and it went all dead. After I had turned off the ignition and taken out the key I heard the starter take another turn (!) When I tried to charge the battery I realized that it now was shorted, only around 2k ohms resistance between the positive pole and ground.

Any smart guys here with ideas for what I should start looking at?

Ty

Sounds like the solenoid is shorted.

 

[Ice]

Thanks for your answers!

The ohmmeter didn't blow out, but apparently it's no good for measuring resistance in a live circuit. I got strange values depending on which way I measured.

Anyway, I disconnected the battery, and even though it was at less than 5V it looks useable.

I then measured the resistance between the cables to the battery and it's zero. So there's a short somewhere.

The starter was changed a couple of weeks ago, so I suppose that's the most probable culprit. But can the solenoid blow just by trying to start with at weak battery?

Any clue to what I should do to pinpoint the problem?

 

[Majorlk]

Thanks for your answers!

The ohmmeter didn't blow out, but apparently it's no good for measuring resistance in a live circuit. I got strange values depending on which way I measured.

Anyway, I disconnected the battery, and even though it was at less than 5V it looks useable.

I then measured the resistance between the cables to the battery and it's zero. So there's a short somewhere.

The starter was changed a couple of weeks ago, so I suppose that's the most probable culprit. But can the solenoid blow just by trying to start with at weak battery?

Any clue to what I should do to pinpoint the problem?

The voltage across the terminals of your disconnected battery is less than 5 volts? If that's correct, your battery is toast! It's dead! It's junk! 5 volts will not pull in the starter solenoid, neither will it spin the starter, even connected directly across the battery.

Time for a new battery!

 

[Ice]

Yes, you're right. It couldn't spin the solenoid. But it has been weak before and I have charged it up to 12 V. It was probably shorted for about an hour too, so maybe that killed it. Anyway I'll buy a new battery on Monday.

But do you think I could have broken the solenoid when I tried to start it with this battery?

 

[ryanlarue]

Thanks for your answers!

The ohmmeter didn't blow out, but apparently it's no good for measuring resistance in a live circuit. I got strange values depending on which way I measured.

Anyway, I disconnected the battery, and even though it was at less than 5V it looks useable.

I then measured the resistance between the cables to the battery and it's zero. So there's a short somewhere.

The starter was changed a couple of weeks ago, so I suppose that's the most probable culprit. But can the solenoid blow just by trying to start with at weak battery?

Any clue to what I should do to pinpoint the problem?

Most reman. starters will reuse things like solenoids. So your "new" starter is actually just a new rotating core.
GET A NEW BATTERY. The battery can also be the cause.

I am only cry out starter because the symptoms sound like. Old Fords with the external solenoids are notorious for sticking on.
The weirdest one I came across was a truck had a bad ground at the starter, when the starter would be engaged, it grounded its self through the external solenoid keeping the starter engaged.

 

[bbottomley]

The ohmmeter didn't blow out, but apparently it's no good for measuring resistance in a live circuit. I got strange values depending on which way I measured.

No, they don't work in live circuits. They put their own voltage on the load, measure the resulting current, and do Ohm's Law. They will indeed get fooled if voltage is already there. Link

 

[Majorlk]

Yes, you're right. It couldn't spin the solenoid. But it has been weak before and I have charged it up to 12 V. It was probably shorted for about an hour too, so maybe that killed it. Anyway I'll buy a new battery on Monday.

But do you think I could have broken the solenoid when I tried to start it with this battery?

Until you get a functioning battery connected, you can't know what is going on with the solenoid. You currently don't know what is working and what is not. Personally, I would let a good electrical shop check out the whole system instead of you just mucking around blindly.

BTW, the solenoid doesn't spin, it sends voltage to the starter and pulls the starter bendix into the flywheel to turn over the engine.

 

[ryanlarue]

Until you get a functioning battery connected, you can't know what is going on with the solenoid. You currently don't know what is working and what is not. Personally, I would let a good electrical shop check out the whole system instead of you just mucking around blindly.

Actually, he could Ohm the connections at the solenoid. If there is no resistance, then the solenoid is disengaged.

How about a corroded relay? Very rare but could happen.

 

[Majorlk]

Actually, he could Ohm the connections at the solenoid. If there is no resistance, then the solenoid is disengaged.

How about a corroded relay? Very rare but could happen.

If there is no resistance across the solenoid terminals, the coil is open and the solenoid is dead.

 

[ryanlarue]

Sorry, the connections I ment to say are Battery in +12v and the Starter output. The 2 big posts for the battery cable/starter cable, not the trigger post.

 

[Ice]

It costs $$$ to have somebody fetch the car. If there was a way I could get it to an electrical shop myself, I'd save a lot.

But I don't really see any benefit in putting in a new battery when there's zero resistance between the battery cables. Would it even be safe?

I'm pretty sure something was broken when I heard that sound and the car died. If it wasn't the battery it must have been something else. Btw it looks like the battery is charging well.

 

[Majorlk]

Well, you came asking for help. We gave you our best thoughts as to the problem. If you choose not to follow them, I wish you good luck finding the solution.

 

[bbottomley]

Isolate!

If you have another car available (or a local friend), take the battery to an auto parts store for a free check.

 

[Easy Fixer]

Fusible Link

Sounds like your car has a fusible link between the battery and the starter. Check to see if it needs replacement. If it does replace it and then jump start the battery and all should be well in the universe!

 

[Ice]

The clueless guy with the ohmmeter has been at it again...

I disconnected both the cable from the battery+ and that other small cable attaching to the starter. I then measured zero resistance between the two connections on the starter as well as to ground. Does that mean that the solenoid is toast?

On the bright side there is now infinite resistance between the two battery cables the battery. I guess that means that the cable between the battery and starter is good (?)

I could take out the starter now, but I don't have a torque wrench to put it back correctly again if it's ok.

 

[Ice]

I pulled out the starter and took it the shop. They said it was dead and would either rewind the solenoid or replace it. In either case I won't pay anything.

Thanks for your help!