tdeffert

So I own a 2002 rx300 and it seems to be having electrical problems. The car sat all winter and started right up in February when I pulled it out of my garage. A week later I went to start the car and it had a dead battery. I charged the battery and cleaned to terminals and the car has worked fine since. I have drove the car every day this past week, starting right up every time, and just today I went to start it and it was dead again. I am starting to think there is a short. Now a little while back while I was driving the car all of the lights on the dash starting flashing and the needles were bouncing up and down. I simply pulled over, turned off the car, started it back up and everything was fine. I have read some problems with the computer system and am starting to think that may be it. Has anyone got any advice or experienced this problem before?

salimshah

Verify the terminals are tight and corrosion free. Then I would suggest visit an auto parts store and have them test your battery and charging system. They can replace the battery right there if you choose.

There is a more detailed test that can be performed but usually the above is good enough.

Salim

Z07

Did you look inside the battery? Does it need some distilled water?

Many parts stores will test a charging system for free. Some require you to pull the battery and alt and take them into the bench. Some will test them on the car.

What is the voltage across the battery terminals with the key off? key on? engine running?

tdeffert

So I am beggining to think that it is the computer. The terminals have been cleaned and yesterday I removed the terminals, hooked them back up and it started just fine without charging the battery. I was going to check the fuses to see if there is a draw but the problem would have to be occurring at that moment and it is an intermittent issue. Has any one replaced either of the computers or is it recommended to have a shop do it?

tdeffert

I got 0 voltage across the terminals with the key off and got 12.65 on the battery. I haven't tried it with the key on or the car running yet

salimshah

The Zero volt reading does not make sense to me.

Voltage is just an indicator for battery test. You have to subject the battery to heavy load to see if it is OK. Testing at the shop is free and is a better way.

Was any work done on the vehicle and it could be one of the ground loops were left unhooked.

Changing out the computer is a last resort and has lot of headaches with key registration etc. I would not opt for that, before trying other things.

Keep in mind, intermittent problems are almost impossible to solve.

Salim

kalali

Absolutely. You need to rule everything out before indicting the ECU.

tdeffert

Well the 0 volts were with the keys off and it was the terminals so no power should be supplied through the cables correct? The car is an 02 and has 30k miles. It has pretty much sat its entire life, it was my grandmothers so it took the occasional trip t the grocery store.

tdeffert

I just feel like it has to be the computer based off the indicators I have gotten. For instance a check light and vsc light come on. Then when the terminals are disconnected its gone. I didn't have to charge the battery just remove the terminals and the car started. When the battery was "dead" I would turn the key on and be able to move the chair or roll down the windows . I would turn the key off and on again and wouldn't be able to do anything. I went back and forth with this multiple times.

salimshah

I humbly request that you read the FAQ and Having Problems Start here Mega thread, stickies. Some of the things you describe are completely normal indicators of problems ... CEL VSC and clearing out. If there are error codes present, [CEL with or without VSC] please have them read at the parts store too.

It will take much less energy and time to have the battery tested under load. With so much electronics, we need to start with a good battery. Short runs would mean insufficient charging and can lead to shorter battery life. Weak battery can still operate few things till it gets totally discharged. Do you get 1am on the clock?


If no work has been done, we can eliminate un-hooked wires.

Salim