Well I'm going to start by saying that this is my first post, and I really need help, I being having trouble with my car for the past year, it all started with my car not starting one morning, it checked the battery and it was dead, I got it charged and on my way to the dealer, I notice that the needles on the gauges where bouncing around while driving, then the right arrow (turn signal) the check engine and the break lights where flashing, the car turned off but since it is a manual tranny I was able to press the clutch and it was good to go again, I got to the dealer, I explained what happen and they check the car for me, a couple of hours later I got a call for the dealer and they said that the only problem was the battery, So i bought a new one, and I wasn't sure...... so i asked for the old battery, I took the old battery I got it charged and its being working since on my dads car, I went back to the dealer, they said that they couldn't found any other problem on the car, they suggested to remove the sound system because maybe there was a short or something, I removed every single cable added to the car, and it still does the same thing, after several months of charging the battery every day I'm desperate I went to autozone to test the alternator and they said it wasn't working, so I got a new one, I got it installed over the weekend and the lights and the needles are still doing the same thing, but now I discovered something else, when I turn on the cruise control and I set a speed, the car starts going crazy, the speed goes up and down by it self, and if goes pretty fast, I already got 4 batteries so far and the alternator and it still does the same thing, I got a CAI, headers, downpipe and exhaust but the engine seems to be running perfect, and when I woke up this morning and I was getting ready to get to school , the same thing happen, when I try to start the car there is no crank just like a noise, but I got the car to neutral and it rolled about a feet and then I tried the ignition again and it work,

Does any body have a clue? I'm even thinking about selling the car, but I really love my tc......

 

Sounds to me like you have a bad ground somewhere. But it is hard to troubleshoot much further than that on the net.

For the charging, that could simply have been tested initially by reading the voltage at the battery terminals while it was running. This should be around 14.4V or so, which indicates good charging voltage. It is obvious (too bad it wasnt to the dealer) that the battery is not being charged properly for one reason or another.

First... find a dealer with a tech that knows how to troubleshoot. Sounds like they are simply making guesses and not actually doing much.

 

^^^ sounds like a bad ground to me as well. check ur main ground terminals for the chassis ground etc. check for shorts and other mishaps while ur at it.

 

I did check the battery and it was at 12.8 while the car was on, got the new alternator and it still shows 12.8 volts while running, any more ideas?? I will check the ground tonight could it be the starter? could that be causing a short?

 

Now this may sound silly, but I had a problem very similar in my 87 supra. All of a sudden the windshield wipers would come on and everything would go nuts. Then if I turned off the car it would not come back on, but the battery was good. My problem was the main positive wire that went to the fuse box to the positive side of the battery, had stripped out of the connector that attached to the battery, and was loosely touching the battery. When the car was on, the alternator would take care of everything but the main wire that went to the fuses, would spike all the electrical systems when it touched the positive. Check that the wire is not stripped out anywhere around their, tug on it, and check that it does not slip out of where it is connected. This is the only advise I have, but it sounds really similar to my old problem.

 

If the battery voltage read 12.8 when the car was running, the charging system is not working. First, have you thoroughly cleaned and inspected your battery cables? Have you checked all fuses? If you look in your owners manual, you will find fuses related to the charging system. Be sure to check these, and not just visually since they sometime appear good even though they are not. Check voltage on both sides of the fuse. If the charging system is completely offline, then you should have a charging system warning light on the dash illuminated, but you are obviously not charging correctly, so this needs to be checked.

If that all looks good, you need to check all wiring to the alternator (on both ends of the wiring) and to the battery. Then as mentioned, all the main grounding points.

 

I checked all fuses, and both cables on the alternator and the battery, I will be checking ground cables tomorrow, and the cables that go to the fuse box, it wierd cause I disconnected the battery while the car was running and the car was still running, I notice something funny tho, I was charging the battery and the neddle that tells you the voltage was jumping all crazy, I'm thinking a short.......

 

12.8 may be typically ok when the car is off... but when the car is running and current is flowing, naturally the voltage will be higher bc of increased current... like engifneer said, 14.4ish is around where is should be. 12.8 is a pretty notical defecite

 

14.XX volts is what is required to cause charging in a 12V battery, so if it is much lower (which 12.8 is much lower) then it is not charging for one reason or another. The alternator has to produce the 14.X volts in order for charging current to begin flowing in the battery.

I am a bit confused when you say that the needle that tells you the voltage was jumping all crazy... do you mean on an external meter that you were using to measure it? There is no volt meter on the tC's gauge cluster.

 

^^^ good explanation, kinda what i was trying to say, but you worded much better. yea my tC definately doesnt have a batter meter... perhaps he was using an analog volt meter as u stated?

 

sorry for the confusion, it is a external meter, that its on the battery charger, should I put back my old alternator? since the new one doesn't seem to be doing any better? and I'll just keep looking for any loose power or ground cables today; if there is a short somewhere, is there a way for me to try to find it? like if I start the car, can I check the fuses will there be a change of voltage?

 

put some jumper cables on ur nipples, but only after u wet them, put the other end on ur battery and then just wiggle wires until u feel the tingle get hotter, tighten the wire up that induced the more tingle and ur good to go. jk


actually, engifneer would know better. i could give u some ideas, but i dont wana give u bad advice.

 

[quote="FlintC"]put some jumper cables on ur nipples, but only after u wet them, put the other end on ur battery and then just wiggle wires until u feel the tingle get hotter, tighten the wire up that induced the more tingle and ur good to go. jk

hahah, I tried that already...........


I'm going cable by cable in the engine bay, no luck yet..

 

Some times the loose connection can be right at the battery terminal. Those wires are moved more than any other. Mine was right were the cable meets the positive, I could pull on it and it would not come apart, but when I disconnected it fell out.

 

Since the fuse should be practically a zero ohm load, the voltage drop will be across the load...

In other words, you should read battery voltage on both sides of the fuse if the fuse is good. I you only read it on one side, the fuse is bad.

 

OMG!!!! After more than a year I found the stupid problem!!!!!!! thanks everybody for all the good advices, I checked cable by cable on the engine bay, and the last one that I expected was the problem, The main ground that goes to the engine block just under the starter was loose, I removed the starter, got the cable's nut tight, the starter back to its place and THE CAR GOES BACK TO NORMAL!!!!!

Im so happy!!!

 

Cool! glad you found the problem. Electrical gremlins suck, I lost my favorite ride due to an electrical gremlin. Glad we could help, that is what is so great about this forum.

 

Glad you got it fixed!

happy bday bean

 

Thanks man, I appreciate it.