Scary experience - Toyota Nation Forum : Toyota Car and Truck Forums

t3chnique · 01-30-2010, 01:41 AM

Today, while driving on a street near my house, I lost all power too some auxiliary components (radio, cig lighter, etc.) It happened while I was slowing down for a stoplight. The car didn't die though. Poped the hood later and saw the negative battery connector had some play.

Anyone know what happened in that brief second of power loss? If this had happened on the freeway, things might have been worse.

Jimnist · 01-30-2010, 02:14 AM

If the engine is still turning over, its creating electricity to power the ECU (and related components) and mechanical controls i.e. vacuum assisted braking and power steering.

eyezack87 · 01-30-2010, 03:05 AM

Jimnist is right, after the car starts, you can take off the terminals to your battery and it should keep running due to the alternator

However, I have had this problem before. Though in my case, I lost all power in the middle of a very busy intersection. Anyway, check your alternator regularly. That was the cause of the power failure in my car

bigbird · 01-30-2010, 10:38 AM

^ just dont test the alternator by doing this ^. it damages the alternator and if you test it enough, youll brake it

.

t3chnique · 01-30-2010, 11:15 AM

So are you guys saying my alternator might be going? It's got around 90k on it I believe

73sport · 01-30-2010, 06:40 PM

No, probably not.

Yes, the alternator can output enough current to run most of the cars accessories at full output. However, during normal driving, most of us let off the gas allowing the engine to idle at a stop (for example). In this case an open (defective battery) or disconnected battery forces the car to run on the alternator output alone. The problem is accessories like A/C, blower fans, head lamps 55watts (x2), (65w X2 w/high beam 110w+130w), ignition system, ECU, Fuel pump. ect all take energy and at idle – there’s no more to give so the car turns off!

I had a battery open once during startup. I turned the key and internal plates just melted away leaving just a couple volts output from the battery. I was out in the middle of nowhere with no options to get home so I turned off every accessory and yanked one of the low beam bulbs and drove it 50 miles on the alternator after getting jumped (the battery, not my bones). With both headlights and the brake lights on it would die at idle. Hence the reason I yanked the low beam bulb on one side. That 55 watts was the difference between running at idle and not running when the brakes were pushed.

It was the 95 Camry.

Edit: no its not a good thing to do to the alternator running without the battery and is not a valid means of load testing IMO.

bigbird · 01-30-2010, 07:36 PM

if the negative terminal had play then its likely just the connection. pop the cable off and make sure to clean the terminal then tighten the cable back down.

eyezack87 · 01-30-2010, 08:33 PM

Quote:

Originally Posted by bigbird

^ just dont test the alternator by doing this ^. it damages the alternator and if you test it enough, youll brake it

.

Very true but in theory its supposed to be that way. I'll get a rental for my next service to try it

To the OP though, you could turn off everything unnecessary to try to make sure you don't stall but there is a point where it wont work anymore. Hence how I got stuck in the middle of an intersection. I had a nice panic video to prove to my service manager though. I said things I don't remember saying

t3chnique · 01-30-2010, 11:26 PM

73sport, so your thinking I have a defective battery? I just got mine changed last summer!