OK My son in law hooked the battery the wrong way, guess what it won't fire, it just turns over with no fire. we chnaged out the one fuse 85amp nothing. does anyone have any suggestions? it is a 1991 toyota camry
Look at all the fuses, under the hood, and the fusible links. Hopefully you missed one.
You may also have partially or completely fried the alternator.
Stewart DIBBS
DJMoose: Today, like right now - go get a 120V (240V for UK) line powered battery charger connected and get the car's battery back to a full charge. The 10-amp size is plenty.
If you let lead-acid starting batteries set for long while partly discharged or totally flat they will get sulfated and ruined - and there's another $50 right down the tubes.... Then you can keep tracking down the other problems.
Killed the alternator /or/ popped a fusible link on the large charging lead from the alternator output stud to the battery. Even if you fix every other link and fuse on the car, every other system is working fine, if the battery isn't charging you won't run for long.
If the engine is running at 'fast idle' (above 1500 - 2000 RPM), you should have something between 13.8 - 14.5 volts DC (depending on the temperature, hotter=higher) on the output stud of the alternator, and at the battery terminals. If you see anything below 12.5 volts, the alternator is not putting out enough power to charge the battery. Use a decent digital volt-ohmmeter - it'll cost you $20, and will last for many years. Continuity check for fuses, etc.
The little plug on the alternator will have three or four leads on it, and you can use the meter to see if the signals that are supposed to be there are in fact there - if the alternator doesn't see power on the accessory lead it won't "turn on", even if the car is running. One lead will be accessory switched power, another is +12V that goes through the "Charge" warning light on the dash, and it might have an always-on 'battery reference voltage' lead coming back through the harness... Check the shop/repair manual for your model.
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Do all of the lights on the dash come on? If the check engine light doesn't come on you may have missed a fuse or you may have damaged a realy. if you have checked all of these and they look ok, pull out the main fuses under the bonnet and use a test 12v test lamp to check them. I have seen plenty of those that look ok but won't allow a test lamp to light. But be prepared for a worst case of a damaged ECU. if you can't find one from a car recycler you can kiss the car goodbye. If they are aviable form toyota they will be worth more than than the car.
All good points, but the ECU is pretty well protected by fuses and crowbar diodes to (try and) make sure the reverse polarity doesn't get inside to wreak havoc. And there are multiple power leads with their own protection, you have to find and fix them all.
The ECU is a classic Red Herring - one of those things you can suspect, but don't change until you've exhausted every other possible option, unless you can see the Magic Smoke ;-) coming out of it they usually aren't the real problem. Someone here (Ray O.?) mentioned that 98% or so of the ECU's exchanged as Absolutely 'I'm Sure Of It!' Bad test good when they get back to the repair depot...
And as you said, they're ridiculously expensive new, and the wrecking yards know that too so you still pay dearly for a used one.
Good thing the OP found the hidden fuse and got the car going.
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I think the figure for Toyota ecu's is over 99%. I've looked at my share of problem vehicles and have never personally run across a bad one.
Glad to be of assistance! Thank your Lucky Stars you didn't snap the ECU!!!
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