2000 Jetta 2.0 Gasser

My customer's 2.0 gasser Jetta is stuck. I'd like to try to help her out as I think $$$$ is tight.

Car won't start. Battery looks old but the flashers and such light up good and bright. She and her friend said they tried to jump it to no avail. I tried to start it today. I jiggled the key, moved the shifter back and forth through Drive and Neutral and I checked some fuses though I wasn't sure which ones were important. I don't understand the heiroglyphics fuse card.

When I turn the key to start I noticed a quiet hum sound but no clicking.

My novice thought is the starter is dead. Which fuse or fusable link is for the starter? Would I hear that hum if the fuse was blown?

Your thoughts are appreciated. I am hoping to help her get it fixed painlessly and correctly though I have no plan to do anything like change the starter for her......

Check do you get 11-12V on starter solenoid wire when the key is in starting position.
If you do then starter is out. If you don't then turn key to ON and give 12V and see is it going to start.
If is starts or cranks then you have to check power form Ignition switch to starter.

Thanks 97.

Anyone have a thought on what the hum might be in the start position?

Another thing you can check is the battery voltage when trying to start. It should drop to almost 0. this indicates at current is flowing through the battery. If this does not happen then the starter is not getting power.

Mr Wizard said:

Another thing you can check is the battery voltage when trying to start. It should drop to almost 0. this indicates at current is flowing through the battery. If this does not happen then the starter is not getting power.

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Are you sure this is true?

I would expect the voltage to drop, but to stay above 12.6. If voltage dropped to 0 then you would have all sorts of issues (ex: ecu would not be powered).

A voltage drop to 0 would indicate to me that there is more current draw than the battery can handle.

puter said:

Are you sure this is true?

I would expect the voltage to drop, but to stay above 12.6. If voltage dropped to 0 then you would have all sorts of issues (ex: ecu would not be powered).

A voltage drop to 0 would indicate to me that there is more current draw than the battery can handle.

Click to expand...

Can double check tonight, but I think this is the case.

Christian

P = V * I

No voltage, no power.

Mr Wizard said:

this indicates at current is flowing through the battery..

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This indicates you need a NEW battery.

The hum you are hearing is the fuel pump. It comes from the back of the car and on later models it came on when the drivers side door opened. It should hum for about 2 seconds then shut off. Thats very normal. Things to check would be the shifter to make sure it knows its in neutral or park. Also check the ground strap. Lastly go check out VWVortex and ask in the 2.0ltr forum. Good luck.

Thanks for all this info. I checked here because I know this site best. I don't know how deeply I will get involved with this car since I am not that "bright" in car repair. I did move the shifter all around to see if it is the interlock "thing". Still could be that though. I like the Wizard's idea also. I'll grab my multi meter and see if the starter is getting any power. After that I think I will have to bow out. If she had a diesel I would have some more experience to draw from.
Thanks again. With a little luck perhaps I can be a hero and help out.

greengeeker said:

P = V * I

No voltage, no power.

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Agreed but you are measuring the voltage with a high resistance device. When the circuit is open to the starter is a lower resistance circuit. The current would then be low through the voltmeter.

Mr Wizard said:

Agreed but you are measuring the voltage with a high resistance device. When the circuit is open to the starter is a lower resistance circuit. The current would then be low through the voltmeter.

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If you are measuring voltage then there will be almost no current flow through the multimeter.

If a multimeter measures voltage it sets its internal resistance to something in the area of megaOhms. In fact, the better the meter the higher the resistance and the lower the current flow. A meter should be able to correctly measure the voltage across battery terminals regardless of circuit loading. 0 volts across the terminal means no power.

Are you thinking of measuring current? If you measure current then the ammeter is placed in series with the circuit and has a very low internal resistance so as not to impact the load of the circuit.