P1675 Porsche fault code 658 - Fault - engine purge fan

[jpflip]

Trust me, I can use all the help I can get :) (and be very grateful for it). Thanks Ahsai, you were very helpful on my o2 sensors/cats previously.

I saw those smart fuses at AutoZone so I will go get some now. They were right above the regular fuses I bought.

jpflip - good to know that this must be between the fan and the relay. I'm assuming the connector (in the 3rd picture in my post #41 above IMG_0978.jpg) runs straight to the relay. So does this really have to be one of 3 things:

1. The fan (which it seems like it's not given our tests)

2. The wire that runs from the fan to that 12-pin connection jpflip wanted to look at last night

3. The wire from the 12-pin connection to the relay (I'm assuming there are no other segments in between, that this runs straight to the relay).

The plug in the engine compartment got 12 wires. 2 of them are for the fan. A12 is going to a common ground called ground #8 on the left side of the car. I think it can be seen from under the car. And E11 is our power coming directly from the relay....

[Silver_TT]

Just bought these at AutoZone and am going to install now. I will follow Ahsai's instructions with the fan and the 12-pin harness to start......:

"Plug it in and let the fuse blow. After that, the LED on the fuse will light up whenever the circuit is powered (when you use durametric to turn on the fan). Now you can go disconnect each segment of the cable starting from the fan end. If the LED goes out, you found the segment that is shorted."

[Silver_TT]

I put in the LED fuse. Had durametric turn on the engine purge blower. Looked at the LED fuse, sure enough the LED fuse is lit up as I would expect. However, as soon as I unplug the wire from the fan the LED fuse goes off.

Does this mean it's the fan that's causing the short??????

[jpflip]

With the fan unplugged select durametric function engine compartment fan "ON" what happen with the fuse? Sorry I've never used those fuse before. I don't think they are resettable and the only feature is once blown a light come "ON" to facilitate the identification in the fuse box....

Edited June 16, 2013 by jpflip

[Silver_TT]

jpflip - with the wiring harness uplugged at the fan, and telling Durametric to activate the Engine compartment purge fan, the LED light on the B4 fuse does NOT light up.

This means it must be the fan, no?

Edited June 16, 2013 by Silver_TT

[jpflip]

Obviously the fan seems to be pulling too much load. You are at the fan and nothing blows, my guess the fan is at fault...Strange behavior that can be test using an ammeter in series with the red and black wire but I'm not sure how many amps the fan should pulled....doing some research now....

[JFP in PA]

Boy, I take a quiet morning and you guys are having a fun time..............

To check the amperage draw on the circuit at the fan, you will need to put an amp gauge of some sort in line with the circuit at the fan connection.

[JFP in PA]

And the fan's current draw would have to be less than the rating on the line fuse.

[jpflip]

JFP leave me your phone number, next time I will wake you up!!!! :D I am going in my garage with my computer and an ammeter. I will give you the exact amp the fan should pull! You are right, it should pull less tan 15 amps!!!

Edited June 16, 2013 by jpflip

[JFP in PA]

JFP leave me your phone number, next time I will wake you up!!!! :D I am going in my garage with my computer and an ammeter. I will give you the exact amp the fan should pull! You are right, it should pull less tan 15 amps!!!

Yeah, that would be real popular on the home front.....................not! :eek:

[Ahsai]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)

However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.

Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Edited June 16, 2013 by Ahsai

[jpflip]

JFP leave me your phone number, next time I will wake you up!!!! :D I am going in my garage with my computer and an ammeter. I will give you the exact amp the fan should pull! You are right, it should pull less tan 15 amps!!!

Yeah, that would be real popular on the home front.....................not! :eek:

Of course I was just kidding JFP!!! I think we can consider Silver fan at fault! I was unable to check the current draw of my fan due to a faulty multimeter. Good to know that I need a new one now!!!

Fan part# 996 624 036 04 and only $74.80 at Sonnen....

[JFP in PA]

The "cool tool" to test the circuit would be a clamp on ammeter:

The clamp and the top goes around the wire you want to test and gives very accurate readings of the current draw (amps) on the circuit. But as these things cost about $300, an inline cheap ammeter would be the way to go; or you could jump for this $12 beauty from Harbor Freight:

[JFP in PA]

JFP leave me your phone number, next time I will wake you up!!!! :D I am going in my garage with my computer and an ammeter. I will give you the exact amp the fan should pull! You are right, it should pull less tan 15 amps!!!

Yeah, that would be real popular on the home front.....................not! :eek:

Of course I was just kidding JFP!!! I think we can consider Silver fan at fault! I was unable to check the current draw of my fan due to a faulty multimeter. Good to know that I need a new one now!!!

Fan part# 996 624 036 04 and only $74.80 at Sonnen....

I knew you were kidding; but my better half goes to great lengths to make sure I am not disturbed when I am away from the shop.

[Silver_TT]

Ok, jpflip, well I don't feel so bad now that I couldn't get an ammeter. I went to Auto Zone and Home Depot both and even for $150+ all the multi-function meteres that include DC amperage measurability only go up to 10A. What's up with that?

So, correct me if I'm wrong but it sounds like we are all in agreement that this is very likely the fan itself. jpflip, looks like that part # you have has been superceded. My fan looks like it already has been replaced because it shows part 997 624 046 01 (Loren says US MSRP is $119.85). I will call Sunset when they open in 1.5 hours and get this ordered. Hopefully it will be here middle of this week.

While I would have liked to test this with a ammeter to drill deeper it seems like it's we have enough information to say, while not completely definitively, but highly probable that this is something to do with the fan.

I owe all of you a huge thanks for guiding me through this. Will post the results once the fan gets here and I put it in (looks like a cakewalk to do).

Edited June 22, 2013 by Silver_TT

[Silver_TT]

Don't feel bad JFP. My better half is German (like real German, not of German descent). If this ends up being the fan I know she is going to point to that "Made in Italy" sticker on the fan (see post #5 of this thread) :huh: . I'm trying to get this fixed ASAP while she is out of the country because when she's back I'm not going to have much time to work on it.

Thank you guys!!!! :notworthy:

[JFP in PA]

Ok, jpflip, well I don't feel so bad now that I couldn't get an ammeter. I went to Auto Zone and Home Depot both and even for $150+ all the multi-function meteres that include DC amperage measurability only go up to 10A. What's up with that?

So, correct me if I'm wrong but it sounds like we are all in agreement that this is very likely the fan itself. jpflip, looks like that part # you have has been superceded. My fan looks like it already has been replaced because it shows part 997 624 046 01 (Loren says US MSRP is $119.85). I will call Sunset when they open in 1.5 hours and get this ordered. Hopefully it will be here middle of this week.

While I would have liked to test this with ammeter to drill deeper it seems like it's we have enough information to say, while not completely definitively, but highly probable that this is something to do with the fan.

I owe all of you a huge thanks for guiding me through this. Will post the results once the fan gets here and I put it in (looks like a cakewalk to do).

It is looking more and more like a fan issue as you have pretty much eliminated everything else.

Decent clamp on ammeters (we have a Fluke 325, which is very accurate on the low DC voltage and current you would find in a car), but these things get expensive quickly. We can justify the expense because we use it everyday, but they are a bit much for the DIY market. But as they say, "He who dies with the most tools wins............."

Go put your feet up and knock back a couple cold ones. :cheers:

[jpflip]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Very good point Ahsai, thanks for sharing your knowledge.

[jpflip]

Just checked and the part# is in fact supersede by 99762404601. Too bad we could not check the current draw but we have to admit, after all the test you've done, the fan has to be at fault. Good luck with the installation of a new one and , of course, let us know if it work!!! Welcome it was a pleasure to help you.

[Ahsai]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Very good point Ahsai, thanks for sharing your knowledge.

You're welcome. It's been fun following this thread :)Btw to the OP, I think it would still be worthwhile to put a fuse in series with the fan and power it up directly from the battery/ctek. If the fuse blows, we can be sure it's the fan. All it costs is a fuse, no need to get any clamp meter.

[JFP in PA]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Very good point Ahsai, thanks for sharing your knowledge.

You're welcome. It's been fun following this thread :)Btw to the OP, I think it would still be worthwhile to put a fuse in series with the fan and power it up directly from the battery/ctek. If the fuse blows, we can be sure it's the fan. All it costs is a fuse, no need to get any clamp meter.

DO NOT use the CTEK for this, its has only low current capabilities for maintaining memory settings trying to run a 15 amp circuit with it will blow the fuse in the CTEK unit........

[Ahsai]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Very good point Ahsai, thanks for sharing your knowledge.

You're welcome. It's been fun following this thread :)Btw to the OP, I think it would still be worthwhile to put a fuse in series with the fan and power it up directly from the battery/ctek. If the fuse blows, we can be sure it's the fan. All it costs is a fuse, no need to get any clamp meter.

DO NOT use the CTEK for this, its has only low current capabilities for maintaining memory settings trying to run a 15 amp circuit with it will blow the fuse in the CTEK unit........

JFP, thanks for catching that. I didn't realize we're talking about 15A since that fan looks puny to me. Ctek can supply up to 7A in supply mode though for future reference. Use the car battery with a 15A fuse in series then.I just measured my fan (996 c2) using a 12v security backup battey. It draws ~6A initially for a split second then goes to 3.5A at steady state.

[JFP in PA]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Very good point Ahsai, thanks for sharing your knowledge.

You're welcome. It's been fun following this thread :)Btw to the OP, I think it would still be worthwhile to put a fuse in series with the fan and power it up directly from the battery/ctek. If the fuse blows, we can be sure it's the fan. All it costs is a fuse, no need to get any clamp meter.

DO NOT use the CTEK for this, its has only low current capabilities for maintaining memory settings trying to run a 15 amp circuit with it will blow the fuse in the CTEK unit........

JFP, thanks for catching that. I didn't realize we're talking about 15A since that fan looks puny to me. Ctek can supply up to 7A in supply mode though for future reference. Use the car battery with a 15A fuse in series then.I just measured my fan (996 c2) using a 12v security backup battey. It draws ~6A initially for a split second then goes to 3.5A at steady state.

A lot of people make that expensive mistake, often damaging the CTEK before the fuse lets go.

[Silver_TT]

Assuming the Turbo pulls the same or similar amps as the C2, that's pretty low amperage. Wouldn't my $2 multimeter from FleaBay be capable of measuring this? If so, does the multimeter need to measure this while the power is already being supplied from the power source? Or is the multimeter capable of measuring this if I just contact the two leads on the multimeter to the two leads on the fan?

As far as the direct battery -> fan connection with a fuse in the middle, that makes a lot of sense and conceptually is very simple. However, it's just me at home today and I don't really know how I would do that with only 2 hands. I would have to solder the wires to the fuse or something and I can't find my soldering gun. If I show up at Auto Zone again they are going to think I'm either stealing or insane.

I forgot that Sunset parts is closed on Sundays but I am going to call then tomorrow at 8am PST to get a fan ordered. Probably will get here Wednesday if they have one already in stock. Looking around at some other places, looks like I should be able to get an OEM fan for around $75 + shipping.

Edited June 18, 2013 by Silver_TT

[Ahsai]

I guess I missed all the fun but good to see you're making good progress. I would consider swapping in a new fan or a known good fan because even if the measured steady current drawn of the fan is less than the fuse rating, it may still blow the fuse. The reason is the DC motor draws maximum current when it starts to spin but as it's picking up speed, it produces electricity in opposite direction, which reduces the current drawn at the steady state. If the motor somehow get stuck even momentarily, it will blow the fuse (e.g., if you hold the blades with your hand)However, check the steady current first if you can. If that exceeds the fuse rating, you found the sucker.Btw, you can actually put the same fuse in series with the motor and supply 14v or so to power up the fan and see if the fuse blows. That would be a definitive test. 14v you can get from an idling engine or your ctek.

Very good point Ahsai, thanks for sharing your knowledge.

You're welcome. It's been fun following this thread :)Btw to the OP, I think it would still be worthwhile to put a fuse in series with the fan and power it up directly from the battery/ctek. If the fuse blows, we can be sure it's the fan. All it costs is a fuse, no need to get any clamp meter.

DO NOT use the CTEK for this, its has only low current capabilities for maintaining memory settings trying to run a 15 amp circuit with it will blow the fuse in the CTEK unit........

JFP, thanks for catching that. I didn't realize we're talking about 15A since that fan looks puny to me. Ctek can supply up to 7A in supply mode though for future reference. Use the car battery with a 15A fuse in series then.I just measured my fan (996 c2) using a 12v security backup battey. It draws ~6A initially for a split second then goes to 3.5A at steady state.

A lot of people make that expensive mistake, often damaging the CTEK before the fuse lets go.

Actually the ctek has circuits to potect itself from overloading in supply mode. Way smarter than I thought. From the owner manual" In this mode, MULTI US 7002 can also be used as a power generation unit for operating equipment that requires 13.6V and a maximum of 7A. If the selected current exceeds 7A, the output voltage will drop as the load increases. The charger has electronic overload protection in this mode, which is activated if the charge is so great that the output voltage from the charger falls below around 9V and the current ís around 7A. In the event of an overload, the charger goes into error mode (lamp 0). Supply mode is indicated with lamp D and lamp 5."Is there also a physical fuse inside? I would expect so for last line of defence....maybe i will open up mine and check. The owner manual doesnt mention any fuse.