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Thread ID: 104594 2009-11-02 02:33:00 Diagnosing strange car problem - ideas? forrest44 (754) PC World Chat
Post ID Timestamp Content User
826386 2009-11-02 02:33:00 See if you can figure this one out..

1987 Corolla lift-back
Car won't start, however, battery is not flat
Had problem intermittently before, but now it's come back

What happens is:
1) put key in ignition
2) turn to ACC - clock display comes on as usual
3) Turn on any electric thing that draws more current - the car's whole electric system shuts off.

(3) used to be triggered by turning the key to ignition and starting the starter motor.

However, the problem has now deteriorated to the point where anything using any more battery current than the clock will shut the whole electric system off. For example, turning key to ON position (dash lights), pushing the brake pedal (brake lights), or using the centre light on the ceiling.

To get the clock to come back on again, you must first turn the key back to the Lock position.
It should also be noted that every time the electric system shuts off, the clock's time is reset.

Any ideas? I have no idea what's wrong, and ideally want to fix it myself
Any tips would be greatly apprecieated :thumbs::thumbs:
forrest44 (754)
826387 2009-11-02 02:41:00 Very bad/dirty/corroded connections on battery terminals. zqwerty (97)
826388 2009-11-02 02:47:00 Have you checked the earth wire. Use jumper lead to test contact.
Also main wire to ignition switch probably starts at battery could have high resistance connection. Try wiggling wires when someone turns key.
Confirm battery is grounded at negative earth post?
Sorry to doubt you on battery but have tried jumper leads from another battery?
prefect (6291)
826389 2009-11-02 02:47:00 How did you test the battery? Colpol (444)
826390 2009-11-02 02:53:00 Cheers for that, it was a loose battery terminal

Why would a loose terminal cause the whole thing to cut out randomly and come back on again?
forrest44 (754)
826391 2009-11-02 02:58:00 How did you test the battery?

with a multimeter, and last time the problem happened it was not flat
forrest44 (754)
826392 2009-11-02 03:03:00 Cheers for that, it was a loose battery terminal

Why would a loose terminal cause the whole thing to cut out randomly and come back on again?

Any movement of the car would make or break the minimal contact between the post and the clamp.
Colpol (444)
826393 2009-11-02 03:04:00 Multimeter does not test a battery properly unless the reading is taken after a load. prefect (6291)
826394 2009-11-02 03:05:00 The real test of a battery is: does it start your engine? Simple .

You likely have what the other posters said - a faulty connection at/near the battery itself . Corrosion and verdigris can create havoc in electrical systems - especially those that pull heavy amps (starter) .

Take the cable ends off, wash in PLAIN WATER and lots of it, removing the corrosion and use NO OILS, SALVES OR OINTMENTS on the battery posts at all .

Also - even SEALED-FOR-LIFE batteries can accept water in the cells - most have removable caps (condensing devices) and you can top them up with fresh, clean water .

The days of DI water and purified water are pretty much passed now, as batteries can take a lot of water with contaminating elements in them and not be fazed by it at all . Pretty much any water you can drink is acceptable . Really!
SurferJoe46 (51)
826395 2009-11-02 03:48:00 The days of DI water and purified water are pretty much passed now, as batteries can take a lot of water with contaminating elements in them and not be fazed by it at all. Pretty much any water you can drink is acceptable. Really!

Does that mean its now ok to drink the water out a battery? :)
hueybot3000 (3646)
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