The engine is back in now what Part II

osidak · 03-03-2002, 06:57 PM

The car is 78 Euro SC. I rebuilt the engine and got it reinstalled. After filling the engine with oil and pulling the coil wire and fuel pump relay I tried to crank it. Got a loud clicking. After advise I got from here this is where I am .

I had the starter checked. It was working but I am having it rebuilt. So that left me with a working starter but still the engine wouldn't turn over and I got a loud clicking noise when I tried to start the car.

I did some checking with my voltmeter and this is what I found.

I saw 0 volts when I hooked the positive lead to the thick red wire that attaches to the starter and grounded against the transmission. I saw 12.75 volts when I hooked the positive lead to the yellow wire that attaches to the solenoid and I turned the ignition switch.

From here I checked for continuity between the single red wire that attached to the positive battery terminal as seen in the photo below and the red wire on the starter. It read as infinite.
I checked the twin red wire and also the large black cable that attaches to the positive terminal of the battery same results.

From here I unplugged the 14 pin plug that is near the CDI box and checked for continuity between the single red wire on the battery and each pin on the block. Several where hot with the pins 3 and 5 showing the least amount of resistance with pin 7 showing infinite.

From here I checked pins 3 and 5 on the plug with the starter hot wire. Both of these showed infinite but pin 7 showed a good connection. It would appear that I have a break in my connection some where between my battery and the pin block as seen above. I was not having a problem before the engine came out. Is there a connection that I missed. Any suggestions on where to start looking. The wiring diagrams I have (Haynes Manual) are kinda tough to read.

Basically looking for suggestions on how to further proceed. Any and all help is needed and apreciated.

Also what is the with plug in the picture below. It is near the CDI box. The car is 1978 Euro SC

Thanks again

osidak · 03-04-2002, 03:06 AM

I hate to do this but bump

dickster · 08:10 AM

the clicking is the solenoid working. i would get the battery checked out first off. don't just check it for voltage (its probably reading good volts) - have it checked properly by a dealer, they put a device across the terminals that checks how long the thing can last under load (something like that!!

).

even if its new - get it checked

do the simple things first!!

next, check for voltage at the red (+) cable at the starter end with the iginition turned to engage starter (the point where it clicks) if you've got nothing then its got to be the solenoid or bad connection - right??

good luck

osidak · 03-04-2002, 08:56 AM

I haven't load tested the battery all I have done is check voltage. I will have the battery load tested tonight. I will also have the solenoid replaced during the rebuild.

What I am troubled by is that I thought the red wire on the starter should see 12v at all times. Is this true or is the red wire also switched?

In either case When I hook the voltmeter to the red starter wire and ground against the transmission I read zero volts. I have tried turning the ignition switch to the start position also and again read zero volts.

Unless my understanding of the starting system is wrong I think I may have a break somewhere between the battery and that 14 pin connector. This also troubles me as I haven't disturbed any wiring other than the engine wiring harness. However as I wrote in the post above the engine wiring harness appears to be ok.

again thanks

john walker's workshop · 09:19 AM

the only battery voltage at the starter is the actual thick cable from the battery. the other smaller red wire, attaches to the alternator from that terminal. the yellow wire from the ignition switch to the solenoid, which activates it, goes thru the 14 pin plug, but that works (it clicks). in addition, there's a yellow/blue wire that powers the cold start injector system when the starter is activated. if the solenoid just clicks, that's the electromagnet being activated. if there is no battery power to the solenoid at the cable terminal, a click is all you will hear. perhaps it's just a crusty battery clamp.

alan911 · 03-04-2002, 09:13 AM

Mine is a 77. First of all, you have the pin #s on the connector incorrect. They are numbered 1-3-5-7-9-11-13 on one side and 2-4-6-8-10-12 on the opposite side. Second you will get different continuity readings depending on whenther the engine is running or not as each circuit perfoms a different function at a different time. So no use testing circuits through this connector with the exception of the heavy gage red (Gen. B+) and double yelow and Black wires (Starter) on pin 1 and 14. Page 296, trace #102 in the Haynes. For some reason, Porsche put these high current circuits in this crappy connector and these 2 pins corrode and arc and melt over time and cause all kinds of problems.

All the others are for gauge senders. rev.& Stop, Reg, blower, Back=up lites, warm-up reg, aux air, and thermo. And lastly, did you remember to re-attach all the GROUND straps after you re-installed the engine ?? There are a few I think. One by the trans and one at the CDI. If it worked before you took it apart, it seems you forgot something. I did.

Britt · 03-12-2002, 06:07 PM

Did you get this problem fixed? I have almost exactly the same roblem but it seems like I have more issues than yours did/does. Mine does not have voltage on the #14 pin and I appear to have some shorts or something as my pins 2 and 14 are connected on the engine harness side. Do you have continuity on these tow pins? I took the box with the fuses on it away from the engine compartment to clean and then I power washed the whole engine compartment. All sorts of funkiness now. Let me know what you found out. Do me a favor and see if the post I put up tonight jives or disagrees with any of your readings. Thanks.

britt
86 Carrera

Britt · 03-13-2002, 02:29 PM

I took my alternator out to make sure I wired it correctly. It turns out that the big red wire on the starter goes to the B+ terminal n the alternator. This connector has two smaller red wires which are soldered to the big wire adn the connector (B+). From the B+ connectore the two smaller red wires head over to the femal side of the connector and connect at pin 2 and 14. It looks like Porsche did this to carry the current to the starter.

I do not have connectivity to the battery + side either.These two red wires head forward in the wiring harness.

Are we having the same problem and the same situational symptoms?

It just dawned on me that maybe the factory alarm system is messing with me here. Does your car have an alarm?

This sucks. I want to hear my new B&B muffler and shift the new close ratio gearbox I just put in. Argh!!!

britt