Question about Wiring Diagram

[galtenbaugh]

I'm trying to diagnose a Secondary Air problem by tracing the wiring diagrams. My pump doesn't come on, but I've confirmed that the pump and the relay are both working.

On the wiring diagram sheet 19 for the 2000 Boxster, there is a box with the number 26 in it at grid E187. There are a number of RE/BL wires terminating into this box but I can't figure out where this junction is in the car. I know it is a positive (+) voltage, but I can't find what the box represents or where box 26 leads to.

I have determined that the lead from the alternator to the secondary air fuse is dead so box 26 is not part of the solution, but I am curious what the boxes are and how to trace their sources and locations.

George

[Loren]

Exact what fault codes? P0410 and P1411?

[galtenbaugh]

Exact what fault codes? P0410 and P1411?

Yes it's P0410 and P1411. I've determined that I'm not getting power from the generator to post 30 of the relay. Given that this is a 3.4L conversion and I started getting the codes soon after having the alternator replaced at the dealer, this isn't surprising. Either I messed something up with the wiring harness when I converted or something got left off or nicked when the alternator was replaced. I'll have to take off the intake (which I need to do anyway for another reason) and take a look at the back of the alternator.

But I'm curious what the box labeled 26 on your diagram means and how can I find where it goes. I'm assuming that it represents an off page connector to another page of the wiring diagram but where?

Thanks!

George

[Loren]

Exact what fault codes? P0410 and P1411?

Yes it's P0410 and P1411. I've determined that I'm not getting power from the generator to post 30 of the relay. Given that this is a 3.4L conversion and I started getting the codes soon after having the alternator replaced at the dealer, this isn't surprising. Either I messed something up with the wiring harness when I converted or something got left off or nicked when the alternator was replaced. I'll have to take off the intake (which I need to do anyway for another reason) and take a look at the back of the alternator.

But I'm curious what the box labeled 26 on your diagram means and how can I find where it goes. I'm assuming that it represents an off page connector to another page of the wiring diagram but where?

Thanks!

George

Here are the diagnostic for those fault codes.

Check triggering of AIR pump.

1. Check fuse (Maxi Fuse) of AIR pump (on relay carrier 2).

2. Remove relay of AIR pump (on relay carrier 2). Connect voltmeter to pin 3 and ground.

Display: battery voltage

Connect voltmeter to pin 2 (negative) and pin 7 (positive). Start engine (the DME relay must pick up).

Display: battery voltage

If 0 V is indicated, check wiring from pin 2 to DME control module, pin III/11, for continuity.

Push relay back on.

Check electric change-over valve.

1. Remove two-pole connector of electric change-over valve.

2. Connect voltmeter to pin 1 (positive) and pin 2 (negative).

3. Trigger AIR pump with Porsche System Tester 2.

Display: battery voltage

4. Remove vacuum hose of electric change-over valve with the engine running. Check whether vacuum is present.

3. Remove connector of AIR pump.

Connect voltmeter to pin 1 (positive) and pin 2 (negative). Trigger AIR pump with Porsche System Tester 2.

Display: battery voltage

Check air change-over valve and air supply lines.

1. Run engine briefly to produce vacuum.

2. Trigger AIR pump with Porsche System Tester 2.

3. Remove vacuum hose of air change-over valve. If vacuum is present at the air change-over valve, check air supply from the AIR pump to the changeover valve up to the air supply line to the cylinder heads. Check function of air change-over valve.

[galtenbaugh]

Exact what fault codes? P0410 and P1411?

Yes it's P0410 and P1411. I've determined that I'm not getting power from the generator to post 30 of the relay. Given that this is a 3.4L conversion and I started getting the codes soon after having the alternator replaced at the dealer, this isn't surprising. Either I messed something up with the wiring harness when I converted or something got left off or nicked when the alternator was replaced. I'll have to take off the intake (which I need to do anyway for another reason) and take a look at the back of the alternator.

But I'm curious what the box labeled 26 on your diagram means and how can I find where it goes. I'm assuming that it represents an off page connector to another page of the wiring diagram but where?

Thanks!

George

Here are the diagnostic for those fault codes.

Check triggering of AIR pump.

1. Check fuse (Maxi Fuse) of AIR pump (on relay carrier 2).

2. Remove relay of AIR pump (on relay carrier 2). Connect voltmeter to pin 3 and ground.

Display: battery voltage

Connect voltmeter to pin 2 (negative) and pin 7 (positive). Start engine (the DME relay must pick up).

Display: battery voltage

If 0 V is indicated, check wiring from pin 2 to DME control module, pin III/11, for continuity.

Push relay back on.

Check electric change-over valve.

1. Remove two-pole connector of electric change-over valve.

2. Connect voltmeter to pin 1 (positive) and pin 2 (negative).

3. Trigger AIR pump with Porsche System Tester 2.

Display: battery voltage

4. Remove vacuum hose of electric change-over valve with the engine running. Check whether vacuum is present.

3. Remove connector of AIR pump.

Connect voltmeter to pin 1 (positive) and pin 2 (negative). Trigger AIR pump with Porsche System Tester 2.

Display: battery voltage

Check air change-over valve and air supply lines.

1. Run engine briefly to produce vacuum.

2. Trigger AIR pump with Porsche System Tester 2.

3. Remove vacuum hose of air change-over valve. If vacuum is present at the air change-over valve, check air supply from the AIR pump to the changeover valve up to the air supply line to the cylinder heads. Check function of air change-over valve.

I should have been more clear. I'm really asking how to read the wiring diagram. I don't know what boxes 26 and 9 represent on the factory wiring diagrams and your diagram. I've already determined that my relay is opening and closing properly but there is no current getting to connector 30 on the relay from the alternator.

Thanks!

George

[Loren]

26 is a junction point for relay power. Unless there is a break in that line to that relay other relays would not either.

X59/1 would be a physical connector (socket and plug) and 9 would be another junction point where other lines tie in. 9 ties into DME control.

[galtenbaugh]

26 is a junction point for relay power. Unless there is a break in that line to that relay other relays would not either.

X59/1 would be a physical connector (socket and plug) and 9 would be another junction point where other lines tie in. 9 ties into DME control.

Do the wiring diagrams show where the junction points are? It doesn't matter for the problem that I'm working on, it's just bugging me that I can't find something in the diagrams. Are the locations of the junctions identified anywhere? I just want to make sure I can read all aspects of the diagrams.

George

[Loren]

Welding point (junction) 26 is top rear - left side (see red arrow).

[galtenbaugh]

Welding point (junction) 26 is top rear - left side (see red arrow).

Thanks Loren, that's exactly what I was looking for. I was wondering if weld points = junction points.

The reason I think I need to go deep on the wiring diagrams is because, besides the secondary air issue, I am having strange behavior from the car. It's a 2.7L conversion to a 3.4L and it just doesn't seem to have the HP it should. It dynoed at about 250 at the wheels and an Air fuel that was all over the map everything was very inconsistent and there are no other error codes. The shop owner, who is pretty experienced (won the Speed WC GT constructors championship for Porsche back in 2000), suspects it's a ground issue. So I bought a set of back probes for my multimeter and I'm ready to verify all the connections on the harness.

As for not getting power to the secondary air pump, I'm afraid I didn't hook up the little red wire to the alternator when I swapped the harness. I even vaguely remember thinking it was a ground wire and bolting it to the block. Luckily it doesn't hook in with anything else so no harm done except an afternoon of taking the intake off the top of the engine again.

Thanks again for your help.

George

[galtenbaugh]

Welding point (junction) 26 is top rear - left side (see red arrow).

Thanks Loren, that's exactly what I was looking for. I was wondering if weld points = junction points.

The reason I think I need to go deep on the wiring diagrams is because, besides the secondary air issue, I am having strange behavior from the car. It's a 2.7L conversion to a 3.4L and it just doesn't seem to have the HP it should. It dynoed at about 250 at the wheels and an Air fuel that was all over the map everything was very inconsistent and there are no other error codes. The shop owner, who is pretty experienced (won the Speed WC GT constructors championship for Porsche back in 2000), suspects it's a ground issue. So I bought a set of back probes for my multimeter and I'm ready to verify all the connections on the harness.

As for not getting power to the secondary air pump, I'm afraid I didn't hook up the little red wire to the alternator when I swapped the harness. I even vaguely remember thinking it was a ground wire and bolting it to the block. Luckily it doesn't hook in with anything else so no harm done except an afternoon of taking the intake off the top of the engine again.

Thanks again for your help.

George

I checked this morning and the red wire from the hot side if the fuse does appear to be grounded. I must have seen the wire with an eyelet attached and assumed it was a ground wire. If that's the only mistake I made moving the boxster harness to the 3.4, then I guess I'm happy. I remember now that I couldn't find a good place to ground it to, so I put it under the oil tube bolt. Didn't seem to be a great idea at the time and now that seems to be confirmed.

Now I'm wondering how it passed inspection with the secondary air not working. I suspect the tuner map that I had installed at the time suppressed the check engine light. The CEL didn't show up until I went back to the stock map. All starting to make sense now...