My car has been playing up electrically, sometimes when you go to start it there is no power available in the RUN mode. This was intermittent and usually turning on the headlights (after 3 attempts), would clear the fault.

Some nights ago when driving, the car was experiencing a big lack of power. Headlights were dim (and the headlight doors operated slowly), dashboard lights were dim too and the stereo couldn't quite stay turned on. By chance I turned off the rear window defogger and full power came back.

Yesterday I took the gauges cluster out of the dashboard to see if my Check Engine light was blown or not, and I discovered it was completely missing. I then took the bulb out of the Fasten Seatbelts place and put it into the Check Engine place. I put the gauges cluster back in and then the above mention intermittent fault became a permanent one.

I've played with this and that and I can say that the following is true...

The battery voltage is good.
Headlights turn on, dashboard lights turn on, but the headlight doors don't open
Pressing the electric door lock buttons causes the relay to click but the doors never lock/unlock
Courtesy features such as interior lights and the electric seats work

So, I figure fusible link A is fine. But I'm not sure about fusible link B. The battery voltage is 12.2V and I've measured the voltage at the alternator to be 10.80V. This seems like a fairly sizeable voltage drop - would a bad fusible link cause this?

Also, the voltage going into the ignition switch is 10.80V.

When I turn the key to the run position, the voltage drops to somewhere around 0.3V, both inside the car and also at the alternator. As you might guess, the car won't start at all.

I'm going nuts wondering what is wrong with my car. Please help!

 

First at 12.2 volts the battery is essentially in a state of discharge. Simply jump another battery and see if the stuff mentioned works. Also, it is more likely a coroded connection may be part of the problem. Suspect the bad connection at the starter solenoid. It is a tie point for several of the feeds for the cars electrical system. Don't overlook bad battery cables. Voltage with a charged battery and the engine running should be 13-14 volts.

 

And don't overlook RB83L69's favorite example of engineering, the "ESC" (Extremely Stupid Connector) if your car has one:

 

Yeah I know that the battery voltage is low at being just over 12V. But it would be higher naturally if I could start the car, as you say, in the 13-14V range.

The ESC connector, what fusible link does it connect up with? I was getting sub 12V appearing there so does it connect to fusible link B?

Further to my first post, I used a DMM to test the resistance between the positive battery cable, and the terminal on the alternator and it exceeded 200ohms so that could be my problem area.

I thought of a way to narrow down the problem a little. If I connect a cable between the positive terminal of the battery and the battery connection of the alternator this will bypass the fusible link. If I then get full power appearing everywhere then it should prove the fusible link is buggered - right?

 

Yup, that could be it. And yes, Y can use a wire-make sure it is the right guage or it will burn up in your hand.

 

I used a jumper lead between the battery positive terminal and the battery connector on the alternator and I got full power back - wohoo!! The car tried to start when I asked it but the battery was too far gone to do it. But, I'm really happy anyhow!

But, I would like to know more about the ESC connector. With the picture above in mind, which wire leads down to the fusible link? The wire on the left, or on the right?