Can't start '98 Jetta TDI - Stuck in the *Car won't start* thread

Done a bit of searching, but haven't found my answer. I do apologize if this is answered elsewhere...

As the subject line says, I have a '98 Jetta TDI. I'm the original owner, 124K miles.

A couple months ago, after a week of not being driven, it wouldn't start. Battery was dead, but I was unable to jump start it (from our '08 Civic). I replaced the battery, and all was fine for a few weeks.

Then, a long weekend without being driven, and it wouldn't start again. Took it as a sign to start riding my bike to work more often, and let the car sit there for another three weeks.

Anyway, here's the behavior now.

I can put in the key, get all the dash lights, headlights, radio. Depressing the clutch and turning the key, I hear a click in the dash, but nothing else.

I have replaced the 50A fuse that I *think* is the glow plug fuse. It was definitely blown. I say "think" because many things I've read tell me it should be in the engine compartment, not under the dash, where I found it. BTW, I used the pic labeled '98 A3 in Lugnut's "A3/B4 glow plug relay and fuse location" post to locate the fuse. Still, though, the layout of the fuses was different than in this pic.

But, replacing the fuse didn't change the behavior...still the same.

Had my wife try to start it while I listened under the hood. Didn't hear anything from the starter/solenoid, but I did hear a clicking at the front of the engine block. I'm mostly a car-repair newbie, so I don't know what was making the clicking, but it wasn't coming from where the starter is located.

So, this is where I'm stuck in the *Car won't start* troubleshooting thread. This thread says:

"Get out your owners manual and find the fuse that controls the start circuit"

Which fuse is this? My owner's manual says the glow plug fuse is in the engine compartment above the brake booster. I don't know where the brake booster is, though (again, a newbie). Googling has been frustratingly fruitless on this.

Or, is the fuse that controls the start circuit somewhere else?

Sorry, I've rambled on...but would appreciate any help. Even a, "Yo, knucklehead, it's right in this sticky thread here" ;-)

Mark

Get your battery tested. There is either something draining the battery while it sits or the alternator isn't charging the battery while driven.

Also the GPs at this temperature will not be the cause of a no start. Don't worry about them for the time being.

Thanks, greenskeeper!

Just came back from AutoZone, where they put the battery on the tester.

The testing equipment there said the battery had a "Good, low charge". Does a TDI require more than just a "low charge" to get things started?

Anyway, I left it there so that they could give it a full charge. I'll go back later today, bring the charged battery home, and try to start it again.

Updates to follow.

Got the battery back, put it in...no luck.

Same behavior as before: put the key in, turn to the on position, dashboard lights come on, seat belt alarm. Turn the key the rest of the way, nothing.

Is there some other fuse that I should be looking at?

markwilk said:

Got the battery back, put it in...no luck.

Same behavior as before: put the key in, turn to the on position, dashboard lights come on, seat belt alarm. Turn the key the rest of the way, nothing.

Is there some other fuse that I should be looking at?

Click to expand...

How old is the battery you are scr*wing with? Is it the proper battery or a cheap POS? You need to: (1) get the car started; (2) test the voltage on the battery before and after it is running. A bad battery can cause a whole host of problems. Since you started off saying that it started a while back when you inserted this battery it is probably a charging problem ....... but you need a known good correct size battery as a starting point IMO.

The starter is at the very front of the bellhousing, below the left fan motor and PS reservoir. It has a nut holding two big cables and a one wire connector. Disconnect the one wire and put a meter on it or test light and see if you get power when the key is turned to the start position. Be sure the clutch is depressed for this.

If you have power it indicates a starter problem, no power indicates a wiring/fuse/clutch switch/column switch/relay? problem.

You should get a service manual so you can look at wiring diagrams.

This fuse near the brake vacuum reservoir is for the three coolant heaters. Ignore it, completely ignore it, as it has absolutely nothing to do with starting the car.

The engine glow plug fuse on your 98 A3, as is the case with my 97 A3 donor,is located inside the car, up above the fuse and relay block, but even this fuse's condition has no bearing on a no-crank condition. The actual position of the fuse holder in the scheme depends apparently on who was on the assembly line that day.

Check if the clicking under the hood, with the key turned to run, is coming from the N75 boost control valve located on the right (always reference based on the driver's position) near the fuel filter. That clicking from the N75 is normal.

With the transmission in neutral, try turning the key to the start position and holding it there. THEN press the clutch pedal. Is there a similar click heard inside the car as when the clutch is pressed first and then the key is turned? This check is only to determine if the clutch pedal start interlock is functional. If there's no change in sound as the pedal is pressed or released the switch may be bad or out of adjustment.

One last item to check is the alarm / immobilizer. This is up under the dash too. Fortunately the input and output plug and socket mate up to each other so the whole module can be bypassed.

what are the condition of the cables connected to the battery?

thebigarniedog said:

How old is the battery you are scr*wing with? Is it the proper battery or a cheap POS? You need to: (1) get the car started; (2) test the voltage on the battery before and after it is running. A bad battery can cause a whole host of problems. Since you started off saying that it started a while back when you inserted this battery it is probably a charging problem ....... but you need a known good correct size battery as a starting point IMO.

Click to expand...

Well, I bought the battery brand new at NTB 6wks ago. It's their top of the line, 85month warranty. 590 CCA.
According to the guy at Autozone this afternoon, the battery was in fine shape.
I guess I'll need to get it towed to my mechanic to get it started.

markwilk said:

......
A couple months ago, after a week of not being driven, it wouldn't start.... I replaced the battery, and all was fine for a few weeks.

Then, a long weekend without being driven, and it wouldn't start again.

Click to expand...

Here is the important part of his OP. That is why he should start with a known good battery. If it starts, use your voltmeter from there........ If it doesn't start then you can screw around with a $300 starter etc.....

markwilk said:

Well, I bought the battery brand new at NTB 6wks ago. It's their top of the line, 85month warranty. 590 CCA.
According to the guy at Autozone this afternoon, the battery was in fine shape.
I guess I'll need to get it towed to my mechanic to get it started.

Click to expand...

So what does it take to be a tire jockey ..... er battery jockey at Autozone these days? Batteries are wierd creatures.

KLXD said:

The starter is at the very front of the bellhousing, below the left fan motor and PS reservoir. It has a nut holding two big cables and a one wire connector. Disconnect the one wire and put a meter on it or test light and see if you get power when the key is turned to the start position. Be sure the clutch is depressed for this.

If you have power it indicates a starter problem, no power indicates a wiring/fuse/clutch switch/column switch/relay? problem.

You should get a service manual so you can look at wiring diagrams.

Click to expand...

When I can get an extra pair of hands tomorrow, I will try putting a meter on the wire to the starter.

I'm confident it's not the clutch switch, since I can hear the switch when I depress/release the pedal.

Thanks!

thebigarniedog said:

So what does it take to be a tire jockey ..... er battery jockey at Autozone these days? Batteries are wierd creatures.

Click to expand...

Heheh...well, perhaps not much. He connected it to some machine which rated the battery as "Good, low charge"

Lug_Nut said:

Check if the clicking under the hood, with the key turned to run, is coming from the N75 boost control valve located on the right (always reference based on the driver's position) near the fuel filter. That clicking from the N75 is normal.

Click to expand...

Yes, that's the location. Very good, I understand what that was now.

Lug_Nut said:

With the transmission in neutral, try turning the key to the start position and holding it there. THEN press the clutch pedal. Is there a similar click heard inside the car as when the clutch is pressed first and then the key is turned? This check is only to determine if the clutch pedal start interlock is functional. If there's no change in sound as the pedal is pressed or released the switch may be bad or out of adjustment.

Click to expand...

Confirmed that the clutch switch is working fine.

Lug_Nut said:

One last item to check is the alarm / immobilizer. This is up under the dash too. Fortunately the input and output plug and socket mate up to each other so the whole module can be bypassed.

Click to expand...

I will check that tomorrow.
Thanks!

greenskeeper said:

what are the condition of the cables connected to the battery?

Click to expand...

They are the originals. To my eye, they appear to be in good shape. I don't see any fraying. I did clean the connectors also.

markwilk said:

I'm confident it's not the clutch switch, since I can hear the switch when I depress/release the pedal.Thanks!

Click to expand...

Electricity isn't acoustic. Sound is not a suitable diagnostic tool to use to evaluate the electrical function of an electrical switch.

If you can hear a change in the device that the switch controls, then THAT fact can be used to confirm the switch is functional, but then there is no assurance that the device operated by the switch is electrically functional.