I was blowing fuses on my wipers and it turned out the stalk on the steering wheel had drifted a little and was grounding out. You might want to check the turn signal stalk to see if that is it. You seemed to have tried all else.

Rick - Thanks for the response. At the risk of appearing stupid, I am not sure how to perform the check you are suggesting. I know where to disconnect the wires from the fuse on the power out side of the fuse. I am not sure about hooking up the multimeter for the ohms reading you are suggesting. I am guessing that I would put the put a lead at each end of the wire and set the multimeter to the ohms/continuity setting. Is that correct?

While I am in the process of looking stupid, I might as well go all the way. What reading would I expect to get if was good? bad? I assume a bad reading would confirm the uninsulated wire was touching metal. Is that correct?

Are you referring to the rubber flange (grommet) protecting the cable from the body? I don't believe the flange has worn through the cable, but I am not certain - access is challenging. I can move the cable back and forth in the flange, for all I know I could be removing more insulation from the wire every time I do it. I need to get the windshield washer system out of the way to access it from the wheel well.

DonMo - Thanks for the thought. It flashes properly when I run a test wire, so it suggests that the column switch is not the problem.

I feel like I am doing a great job keeping my own post alive, so forgive me, but the help is invaluable.

I connected my multimeter to each end of the wire leading out from the fuse to the headlight bucket. I am not sure if it matters which end (black vs red) of the multimeter is connected to which end of the wires - current flow. I tried it both ways and got the same reading 4.3, which I assume is ohms. Of course, I have no idea if that is good, bad or meaningless.

Note: the ignition was not on during the test, which I believe is correct for this test.

Couple of things we need to know (please don't be offfended if the questions sound basic). Did you have your meter set to ohms? If so, what was the scale setting? Does your meter have a "continuity" setting or an alarm or beeper to signal continuity?

From your post, see if this sounds right. The wire from the fuse block to headlight bucket was disconnected from all power and isolated from any grounding metal. The leads from the meter were connected to the opposite ends of the wire and your meter read "4.3" Correct? If so, you should get some reading as you are measuring the resistance of the length of wire, but it's not clear how high or low that resistance is without knowing the scale.

Now, try this test. With your meter still set to ohms, connect one lead to the end of the wire, and the other to bare metal on the chassis. Do you get a reading? If you do, then there is a current flow from the wire to ground.

Simply put, when you set the meter to ohms and the leads are not connected to anything, the reading should be "infinity" or off the scale as there is no current flow. If you touch the leads together, the reading will be "zero" or close to it because the current (from your internal meter battery) is flowing directly between the leads. When you put a length of wire between the leads, you should get a reading between the two extremes--the amount depending on lots of things like metal type, length of wire, cross section size, temperature.

So...you got a resistance reading on the wire, but we don't know the value. If you do the other test I suggested, the value won't really matter if it's close to the 4.3 because if the wire is sound and intact, attaching a lead to the wire end and the other to the chassis would be the same as having the leads of the meter not connected to anything. The reading on the meter with leads not connected to anything and not touching, should match the reading on the meter with the leads connected to one end of your wire and to the chassis, if the wire is not grounded.

L.J. - there is no such thing as too basic of a question for me when it comes to electrical repair, though I am learning an awful lot during this process.

I have included a photo of a multimeter almost identical to mine. The resistance/continuity is in a different location, but otherwise the same. I think it is one of those auto-ranging units, because there aren't too many different settings. There is a 10A setting, but that is it. I hope this answers your question about scale.

"From your post, see if this sounds right. The wire from the fuse block to headlight bucket was disconnected from all power and isolated from any grounding metal. The leads from the meter were connected to the opposite ends of the wire and your meter read "4.3" Correct? If so, you should get some reading as you are measuring the resistance of the length of wire, but it's not clear how high or low that resistance is without knowing the scale."

Yes, this is all correct. There is no scale to set on the resistance setting on my multimeter that I can see.

I don't recall testing the multimeter leads with them not touching anything, but I did touch them together and got a reading of "0". I did the continuity test you are suggesting and got a reading of .2. Again, I don't know what the scale is, I just set it on continuity/resistance.

I am pretty well convinced that you were correct all along, there is a some uninsulated wire touching between the fuse and the headlight bucket. Unfortunately, I am away from the car for a few days and won't be able to post any more updates until I return in about a week.

I am going to order a fault finder, then remove the windshield washer resevoir from the driver side wheel well. I should have adequate access to properly test the wires.

One thing I don't know about the multimeter readings whether or not a larger ohms reading has any meaning about the electrical fault. Is a bigger number worse than a smaller number? Still have a lot to learn, but I will. Thanks again L.J.

http://forums.pelicanparts.com/uploa...1245522646.jpg

That meter has a continuity tester. When you touch the leads together with it on the ohms scale does it beep?

When you touch it between the wire and chassis does it beep?

Page 19 http://www.metersupport.com/manuals/82314.pdf

Greg,

Follow Rick's suggestion and use the continuity tester and see if the meter beeps when you touch the wire and the chassis, that will confirm a ground fault in the wire. Don't stress about resistance readings if there is a ground in the wire--that is the problem. Your fuse is blowing because there is lack of resistance. The current flow (amps) is "slowed" by resistance in wires and devices (turn signal bulb). With a ground fault (short circuit) in the wire, there is virtually no "slowing" of the current flow(amps) which causes the fuse to blow.

So to answer your question, if you are testing the wire by using the ohm selection and the leads connected to the wire and chassis, any reading is bad because it means current is flowing to ground from the wire, and a low reading would be expected as there is very little resistance (think barrier) to slow the flow of current.

Rick -

Thanks. I'm actually away from home for a few days so I can retest anything. I don't recall the audible beep at all - when I touch the leads or when the resistance test on the car resulted in the .2 ohms reading. I will check this weekend when I get home.

I looked at the .pdf from the link you sent - thanks. I didn't understand the specification section. I think this is saying the 200 ohms would be displayed as .2, and the 200k ohms would be displayed .2k. Is this correct? I need to verify if the multimeter showed an M or k after the number. I will post on Saturday after I get a chance to check.

Resistance
Range Resolution
400 ohms 0.1 ohms ±(1.2% reading + 4 digits)
4k ohms 1 ohms
40k ohms 0.01k ohms
400k ohms 0.1k ohms
4M ohms 0.001M ohms ±(1.2% reading + 2 digits)
40M ohms 0.01M ohms ±(2.0% reading + 3 digits)

__________________________________________________ _

L.J.

Your quote gave me an 'ah ha' moment, now I understand why the fuse blows. So a dirty ground increases resistance which prevents electricity from flowing and a bare wire has little to no resistance increasing flow causing the fuse to blow. Funny how logical this stuff is once you understand the basics.

"Your fuse is blowing because there is lack of resistance. The current flow (amps) is "slowed" by resistance in wires and devices (turn signal bulb). With a ground fault (short circuit) in the wire, there is virtually no "slowing" of the current flow(amps) which causes the fuse to blow. "

NO - Your fuse is blowing because you have an unintended path to chassis.

Active the continuity function like the manual says on page 19... I think you turn it to diode test function.

The reading on the ohms scale should be pretty straightforward.

+1. eliminate that first, as there should be no continuity from the 12 VDC buss to ground, unless a "control" circuit malfunction (switches in the path...)

If you've a short (0 ohms reading on this measurement), you should be able to read it on the normal Ohms function selection. The diode function will look for bias on P/N junctions, providing roughly .7 volts drop across the P/N junctions (forward biased) and Z the other direction (polarity).

Rick-I has it right in checking the 12 VDC buss isolation from ground.

Best,

Doyle

Ok, home from vacation. I am finally starting to figure out how this meter works and to use it thanks to those guiding me. I needed to set the meter switch on the ohms setting, then toggle through the continuity, resistance, diode test and capacitance using the mode button. When the meter is correcty set on the continuity test and I touch a leads together, it beeps. When I touch each end of the wire that I thought was the problem (I disconnected from the fuse box) to a lead, it beeps. When I touch just one end of the same wire to a lead and the other to the chassis, it beeps.

Seems pretty definitive to me. Now, I just need to find the bare spot on the wire. It is the wire between the #9 fuse and headlight bucket that is suspect. I did order a short detector, but it probably will be a few days before it arrives, so I am going to start removing the windshield wiper resevoir under the fender so I can gain access to the area. I'll post some pictures later today.

I have isolated the problem to a single wire, but that wire doesn't seem to be consistent with the bentley manual - at least to me. I also pulled the washer resevoir, and have moved the wire looms to expose the area inside the rubber grommet. I see no signs of abrasion at all, there insulation looks perfect.

Here is the issue with the wire. There are two wires coming off the bottom of the #9 fuse. Bentley only shows one. The black/white wire from the bottom of the #9 fuse to the left headlight passes the continuity check with no problems. The black grey wire from #9 fuse appears to travel the same path fails the continuity check. Bentley shows the black/grey coming from the #5 fuse to the headlight, it could be that it was also routed through the #9 fuse for some reason, but bentley doesn't pick that up in their diagram.

The problem does appear to be the black/grey wire, but I can't figure out where the insulation is broken. It is buried inside a wire harness/loom almost the entire distance. The only exception is behind the fuse box and where it exits in the headlight bucket.

I guess I will wait until I receive my short finder unless anyone has another suggestion for me.

http://forums.pelicanparts.com/uploa...1246205580.jpg

Does fuse 10 have a similar wire? Is there an aftermarket alarm?

Rick - Thanks for the response. Yes, #10 also has two wires from the bottom of the fuse. I didn't compare the insulation colors on the fuse to those in the headlight bucket. By the way, both wires coming from the bottom of #9 had the same metal crimp on them, so they appeared to be factory.

The car does not have an aftermarket alarm,

As a temporary measure I may fish a new wire through the fender and headlight bucket so I can enjoy the car. The end of my Porsche driving season is just four months away. The existing rubber grommets in the fenders will protech it at the metal, but a flying stone in the fender could do some damage to the insulation. The odd thing is that the loom from the headlight bucket through the fender is well protected - in addition to the insulation on each individual wire, there is a heavy rubber insulation around the group of wires leading out of the bucket. I can't see any possible breaks. I even unbolted the fuse box to look behind it and could see nothing suspicious. Hopefully, the short finder will help pinpoint the defect.

I really appreciate your posts, plus L.J. and Ronin. I actually think I may be able to figure some out basic electrical problems in the future. And, I now know how to use my multimeter to perform some basic operations.

If you have any other thoughts, please let me know. Thanks again.

Greg,

Looking back at one of the pictures of the headlight bucket with the looms exposed, there looks to be a brown ground wire in the loom as well--is that correct? After all your explorations, I'm suspecting there may be contact with the ground wire and the wire for your turn lights and that's why you don't see damage along the loom.

Here's what you know: The turn signal wire has continuity with the chassis (ground) somewhere. You cannot see any damage along the loom to account for the short.

Try this test using your continuity setting (beep.) Connect one lead to the chassis, and the other to the brown wire in the loom--you should get a beep. See if you can disconnect the ground and isolate it from the chassis. Next, connect one lead to the brown wire and the other to your turn signal wire. If you get a beep, then you know the turn signal wire is making contact with the brown ground wire. Just a thought that may help you find the fault.

L.J.

Thanks. You observation is correct, there is a ground wire within the loom. It is somewhat odd - there is an additional unused metal tab connector in the ground line that was folded back and taped to the loom with an old cloth electrical tape. I check the other headlight bucket and it was the same, so I wasn't sure if it was factory and they used a single loom for US and ROW, and the tab was used for something else in ROW cars. I will take a clearer picture this evening so you can see what I mean.

I understand the tests you are proposing and you caused me to think of another one. I will test tonight when I get home and post the results. Thanks again. I really appreciate you sticking with this like you have, such good recommendations too.

I will need to buy you a beer some day, not sure when I am going to be in capistrano beach next.

L.J.

I disconnected the all of the ground wires from G106 near the battery, which is the correct ground point according to the diagram. I attached one lead to the ground wire and the other to the chassis and got a beep. The odd thing is what I believed to be the faulty wire (black/gray) was also isolated. I don't think I did everything correct. Also, I didn't re-read your instructions until after I got everything re-assembled, so will retest tomorrow night. Something is screwed up, somewhere. I will have time on Friday (off work) to use my freshly arrived short finder, we'll see if I find anything. I really want to drive this car, so if I come up short I think I am just going to make the test wire a temporary replacement.

Here is the picture of the ground wire with the extra tab, the tab was folded back and tapped against the rubber grommet where the loom enters the headlight bucket. Odd.http://forums.pelicanparts.com/uploa...1246496350.jpg

Greg,

Just to clarify, what you're trying to do is isolate the brown wire from the chassis as a first step, so use your continuity meter to test the brown wire in the headlight bucket until you do not get a beep when touching the brown wire with one lead and the chassis with the other--then you know the brown (ground) is isolated.

Once the brown wire is isolated from the chassis, then do a continuity test between the black/grey wire and the brown. Then, if you get a beep you know there is continuity between these two wires somewhere in the loom.

This may be a false lead, but it is a possibility that I would check if it was my car--just to eliminate a "possible suspect." This is a very odd situation, IMO, because the wires in the loom are rarely subjected to conditions that would cause contact with each other or the chassis, outside of obvious damage from abrasion or heat. If the hot wire is contacting ground (which it is) and it is not the brown ground wire (confirmed by your next test?), then there has to be a break in the loom somewhere where the wire is touching the chassis and that can only be where the loom is in constant contact with metal.

One final thought--if you are able to isolate the brown wire and find there is no continuity between it and the wire to the turn signal, you might try removing the grommets from wherever the loom passes through the sheetmetal, slide the grommet back and see if there is any damage in this area that could account for the grounding.

By the way, I never asked if the initial fuse blowing started all of a sudden, or did you get the car with the problem?

Edit: Something has been puzzling me about this situation and raises a few questions. I looked back at the wiring diagram you posted as well as reread your comments about how yours is wired to fuse #9 instead of #5, so here are my questions: What are the colors of the two separate wires coming from fuse 9?

According to the diagram you posted, the fuse for the front and rear turn lights is shared (black/grey and grey/black) eventhough it is fuse 9 on your car and fuse 5 in the diagram. But in your original post you state that when the fuse blows, the front left doesn't work but the rear left still does! That can't be if the car is wired like the diagram. What else fails to operate when the fuse blows?

L.J.

I understand fully now. I did disconnect all of the grounds from G106, right next to the battery. It is the only one listed in Bentley on this circuit. I still got a beep after placing one lead on the ground wire in the headlight bucket and the other to the chassis, so at this point it appears the ground wire is connected to the chassis somewhere else. I tested all the other ground wires on G106 that I disconnected and they are isolated - no beep. Either the diagram is wrong or the ground and the positive lead are touching each other some place in the circuit that I can't find.

I've had the car for two years and have not had a problem. I took it in for PA inspection and everything was good except the windshield washer. They let me return home to fix it and upon successful completion (tap to free motor), I noticed my turn signal stopped working. Fortunately, they didn't recheck the turn signal. I wasn't working near the turn signal wiring, so I'm not certain if it is coincidental or if I caused the problem. I did remove the washer relay so I could access the pump. Windshield fluid did drip in the area up front and there were some electrical connections that may have gotten damp, but none that were part of this circuit. I dried everything and there has been no moisture since. Every other electrical component seems fine.

I am off work tomorrow. I will get up in the morning and do a little disassembly to try to isolate that ground. I will let you know how I make out.

L.J.

Ok, I finally isolated the ground wires - no beep between ground wire and chassis. I had to disconnect the ground connection with the turn signal in the passenger headlight bucket. I then tested continuity between black/gray wire that I said was bad and the ground wire in the headlight bucket - no beep, no continuity. So the ground wire is not touching the lead anywhere. I pulled the grommets out in both places where they pass through metal - headlight bucket and fender. They were difficult to remove and still in good condition with no apparent abrasions in the loom.

The need to disconnect the ground circuit in the passenger headlight bucket seems suspicious to me. That circuit should ground at G106, but it was disconnected. I have to think about that to try to determine if that is an issue or not.

I also retested the continuity of the bad black/gray wire and the chassis. It beeps, so the black/gray wire must be touching metal somewhere. My test wire is still in place and passes all continuity tests - no beeps. I am going to reinstall the battery and try using the short finder that I purchased. If I can't figure it out, I may just go with the test wire for now. I agree that none of this makes sense. The black/gray has to be touching the metal someplace if it blowing fuses and failing the continuity test.

While I was working in the front of the car I noticed that there was a connector in the front of the car that wasn't connected. I traced the wire back to the a/c relay, then followed the wiring diagram to determine it was the condensor blower motor. I couldn't see where the blower was suppose to connect, since there was no obvious connector on the blower. I removed it to find I have the quietest blower motor on the planet and it uses no electricity. You can see in the picture below the blower motor itself is missing, but I have a lovely motor case.

One thing, I had tested the ground for front condensor blower (the one not connected) and it too was beeping before I disconnected the passenger headlight bucket. It shares the same ground point as the light, so I would guess it is on the same ground distribution. What does this mean? I haven't the foggiest.

I need to stop for today - company coming. Again, I greatly appreciate your help, I wouldn't have been able to get this far on my own. This is turning into a far bigger mystery that I expected.

http://forums.pelicanparts.com/uploa...1246633751.jpg