BigBoosting

I'm having a big problem - My car won't start. A few days ago I drove it around for 4 hours straight without a problem, then when I was almost home, all the electronics in the car shut off and flickered back on and kept doing this until I got to my destination. Then, I tried to crank the car again and it would only start when the emergency brake was up and if I pressed the brake pedal, it would shut off. I tried cranking it again today, and now it won't start at all (even tried with jumper cables in case the battery was dead...The car doesn't even try to crank). What could be the problem? I disconnected my alarm and turbo timer (which both deal with the emergency brake), and still no luck.

Help!
Thanks,
Erica

Zyon13B

When you only turn the key on(not to start it) do all the lights light up(check eng, etc..), or is it totally dead?

BigBoosting

Yeah everything turns on as normal until I press the brake, then they dim.

J.S.J

It sounds like a connection at a main battery cable or battery ground cable. Often the place you place the jumper cables is fine but it's the cable/connection on your car which is damaged. So a jump wont help because the voltage isn't able to be transfered to your cars electrical system. I would make sure all the connections on the battery are clean and tight as well as the other end of each battery cable. I also would look at the fuses next to the battery along with the power connections attached to it. The power has to transfer from the battery to the cables then to the fuse block , then through the smaller cables bolted to it. If they are skewed the voltage will stop. Just wiggle things around the connections. Also if a connection is skewed the spot at which it is damaged will get hot when your loading it. Meaning when your trying to crank the starter. It wont get hot just with the ignition on. Theres not enough current demand until its really loaded . Good luck P.s. an alternator can be in the mix as well.

BigBoosting

Hey, I believe the alternator is fine, did some testing on it today by cranking and then taking off the battery, it still ran. I'm still having the brake problem...but it's now become a problem where anything that uses power will cause the car to shut off. I can at least get the car to crank now and it will stay on until the emergency brake goes down, the brake pedal is touched, windows are rolled down, lights are turned on, etc and then it will cut off. Fuses seem to be ok, a little dark but okay. The funny thing is, it's not consistenly doing this. It will do it probably 90% of the time, but there are some times where you press the brake or put down the emergency brake and it's fine.

I'm lost.

J.S.J

I assume the engine is cranking on its own without a jump, thus the rest as you said is tied to more load added to the system. This in my opinion does not help the diagnosis much. At least the engine is running. You really need to be able to see the voltage value the system has when running. The alternator may be at its maximum and only putting out 20 amps. Any further load starves the system. Thinking further if the engine cranks the battery should have enough to run some extra load. This is not a for sure judgment but its more likely true. Having said that even with a quality alternator if a connection is skewed/damaged it won't be able to feed the circuit more voltage/amperage. You really need to look at the voltage with a meter. Theres no room for assumptions. If the battery is low in charge the charging voltage will be lower but surely over 12.9 volts. if the battery is charged all the way it will be on the higher side 13.4 to 14.0 or so . You really need to see what going on there. From there you can consider the next move.

BigBoosting

On my turbo timer it shows voltage. When the car is running it shows about 13.5, as soon as you press the brake or turn on the headlights the voltage drops bellow 12.5 and as soon as you let off it climbs back up. The engine crank perfect so the battery has to have plenty of power. What do you suggest we look at or check for?

mad_7tist

jsj is on a good path. will the car crank with the headlights on?

Zyon13B

Is it just the brake load that causes this, or is it any type of load(like the A/C, or rear Def)?

BigBoosting

It won't crank with the lights on...well it tries but struggles too much and I don't want to kill the starter or anything. Any kind of electrical load kills the motor

J.S.J

With that information I would place a large bet on the Alternator. If I didn't or couldn't do any further testing. In some cases a battery can cause an alternator seem week. You see the regulator in the alternator looks at the battery state of charge first and determines if it needs a charge and at what rate. Normally battery's don't have much internal resistance and send the correct information to the alternator but if the battery has a lot of internal resistance it will look to the regular like a fully charged unit. Its not likely but good to know. The most likely problem is the alternator or its support wiring. The larger cable leading to the battery or the fuse box near the battery. If there is a poor connection there it will not pass enough amperage to run the added load of the brake lights or what ever. Look at the connections on the alternator. I think its a 10 mm nut. If it looks heated that could be the problem. With FD engines the alternator has a extra peace of hardware to make it easier to connect the cable to the back of the alternator. This is also bolted to the alternator and the other end could be loose as well. If the alternator is overly hot is normally a bad sign in a alternator as well. I do hope the alternator belt is tight?? Just checking...If the bridge inside the alternator is skewed it will work and get hot and maybe make a low pitch growl sound and only put out about 1/4 of its amperage.

BigBoosting

Cranked the car again, didn't have any problems until it got warmed up...and it stayed warmed up fine for a while with no problems...but then the brake or any electrical uses causing the car to die started again. When the car was running fine, the turbo timer said the car was making 13.1 volts at the most. Then when it started crapping out it ranged between 9-10.

Runnin Away

Replace your battery end cables, then get a ground kit it sound like your alternator isn't charging the battery therfore yielding the drainage from any electrical device. Have u check what the voltage is like with the car off and you rolling the window down. That would show you how much drainage your actually putting on your battery

J.S.J

There is a lot of things you can throw at the car. If you have a huge bank account go for it. I suggest simply get a volt meter and a test light. You can get these for about 20 bucks. Charge the battery or just get a voltage reading from you turbo timer. Any battery with less then 10.5 volts "unloaded" is not worth a dime. The battery's are 6 cells each has a potential of 2.1 volts or so. A battery with less than 10.5 has a bad cell. The alternator needs voltage to work. It needs ignition, some kind of resistance like a bulb in the dash or a resistor connected to the I/P cluster. (most have both) This will be the second wire in the alternator connector. The big one is battery voltage. I don't expect you to get this considering what a bad job I did explaining.
Test the alternator output, If what you say is correct and the voltage went from about 13 to 9 after running it, you ether have a skewed alternator or a bad connection real close to it.

BigBoosting

Well, I put in a new alternator....not the problem. I'm guessing something is grounding out somewhere?

Bridge_FD3S

What about the obvious?
Time for a new battery?

J.S.J

Hay,
remember connections are key, the quality of the contact is critical. You need a volt meter!!! Get one there cheep. Once you have that we can zero in on the fault. If you have a skewed ground or power supply it may work fine for a while. With use the cable gets hot because of the skewed connection and begins to transmit less amperage/voltage. When amperage is needed it can't deliver the amount needed to run things. Get a meter and I am sure I can direct you where to go.

BigBoosting

I had the battery checked at Autozone, it's fine. Took the battery out of the car while it was running and it still did the same thing. I have the wiring harness out now, guess I'm going to make sure everything's taped up and make sure everything's tight when I put it back on.

BigBoosting

Well, wiring harness appeared fine. I have a volt meter, but I'm not sure what each thing is supposed to be reading so I guess if I tried to check it, it wouldn't really help unless I knew what to look for.

Also, just a random vague question, I found a brown/white wire with black harness that wasn't connected coming off of the wiring harness and connected it...any clue what that was? Didn't notice any difference once I ran the car.