b5t

Short note=I have two B5's, an A4 and a Passat. This is in regards to my Passat. Please keep replies serious.
I could use some help with it. Fuel pump would not pump when key was turned to run. Hooked alternate power supply to fuel pump and it worked. Tested for voltage on the end of electrical connector, and did not have any. Replaced ignition switch and CEL would no longer come on. I cleaned the ECU pins and now the CEL came back on. I tried to VAG it today thinking maybe there was a trouble code causing all the problems. The VAG would not connect to the car. Between turning the key to run and off a few times, something caused all the dash lights (brake light, CEL, ESD, etc.)not to come on anymore. It is as if the car has no battery what-so-ever.

Mat Indukts Lambos

I'd check the ECT first. It may be that it's leaking into the connector, and coolant is traveling through the wiring harness to the ECU and messing things up.

Second theory, check the fuel pump relay. Check the battery ground. Check all other ground locations. Has there been any work done recently?

b5t

from the ground at the battery, where else could I check. I would also like to know more about the ECT. What does it stand for, and where is it located. I only have a Haynes manual, but I look through there to see what information I can combine with your suggestions, and for locating grounds. Should I also check the ground coming from the ignition switch?

Mat Indukts Lambos

located on the back side of the head, in a black coolant pipe that comes off the passenger side head on a 2.8L, or just the back on a 1.8T. It'll either be black, blue, or green, with a 4 pin connector on it.

b5t

my passat is a V6. Should I disconnect the sensor and inspect it? There isn't much room back there, just enough to fit my hand in there to feel around. I'll check on a different way to possibly access it.