still cat find fault.

86porsche · 03-30-2008, 12:43 PM

hi there,
I have posted about this before but still cant solve the problem. I have no start and the lights on the dash wont turn off with the key. If i leave the car for a few days and turn it over she nearly starts but wont kick over.

here is what iv done so far. got a new ignition switch, new battery, checked grounds as much as possible under dash, engine, battery etc. Over the weekend i took out the starter motor and it works fine on the bench. also disconnected the alternator and checked the wires there. I have left off the starter motor and just connected the positive feed from the battery to the wires that give me juice at the ignition switch to try and isolate the problem with not being able to switch off the lights on the dash.

I still have that problem where the power to all switches and dash remain, so i marked all the relays and pulled them all out to inspect and clean. while all where out i checked for voltage. have 12v at all the 30 pins ezf, fuel pump, Lh relay etc with ignition off. but what i found was that i get 12v at pin 87 for the ezf relay when i turn the switch to on, even though the relay is out. can this be normal? I can turn the dash lights back off by the switch again, but if i put the relay back I cant because i continue to get 12v at 87 when its in!!(so dash lights stay on and cant switch them off).so with the relay out all works fine but when its in the switch cannot work.

I will be putting back in the starting motor when i get a chance and tackle my no start issue which i think is linked but if anyone can let me know what they think is going on i would appreciate it.

Danglerb · 03-30-2008, 12:54 PM

I'll take a shot in the dark on this.

The "green wire" that detects spark at the distributor is bad, and someone "fixed" it by mucking up the wiring.

Maybe that will stir up comments explaining how right or wrong I may be.

Its just a wild guess.

86porsche · 03-30-2008, 01:55 PM

Thanks for staying with me on this one Danlerg.

Could you explain abit more why you think its that green wire?

What about me having power at 87 with no relay?normal?

the previous owner had gone at the wires on the back of the ignition switch alrite, the black 15 and the small yellow had be spliced but the connecting wires went nowhere. if i could find out what these 9 wires do, I could see if they are in the right order. just to add more, the two 15 pins on the switch continue to get power with the ezf relay in. I can pull the switch off and still power remains. im also geting power at 87 on at the interference noice supressor,what is this can you tell me? power at 87 of the headlight washer and the wipers, all with the relays out. if this is normal id like to know but if not it may help.

Randy V · 03-30-2008, 02:10 PM

Model year of your car?

Danglerb · 03-30-2008, 02:11 PM

A noise suppressor is usually for the radio, keeps alternator noise out of the sound. Normally it would be connected to +12v (maybe switched via the ignition key), ground, and the power input to the radio head unit only.

I only sort of understand the "green wire", somebody that really knows will need to really answer. It goes from I think the distributor to the engine brain, and tells the brain when power is going to the spark plugs. When it breaks or is bad no spark signal, the brain turns off the fuel injectors. What I am suggesting is that rather than fix the green wire somebody jumpered things so the car runs without the signal. Its the sort of thing that might be safe to do during 5 minutes of testing, and the sort of thing that might be used for years with some owners.

86porsche · 03-30-2008, 02:27 PM

ok well the supressor has power going to it via the switch alrite.

I will have a look at that green wire then asap. just want to ask if you know, how would someone jump that if it was done and i could trace it to see if anything has come loose?

for those who want to know the year its an 86 euro spec car. 4.7 twin distributor car.

Danglerb · 03-30-2008, 02:43 PM

I see the confusion, I'm not suggesting they jumped the green wire. I'm suggesting they jumpered the input or output of some control relay either in the LH brain or central electric panel so that the car would run without the signal.

One of my cars bypassed the injector power relay by running a wire from the fuel pump terminal up to the front of the car. That sort of thing happens when people that don't understand a wiring diagram very well make changes to the wiring.

Randy V · 03-30-2008, 02:48 PM

The 'green wire' is present only on older non-brain cars - i.e. - '78 - '81.

Danglerb · 03-30-2008, 02:51 PM

Green Wire.
http://www.pelicanparts.com/cgi-bin/PartsLookup/search.cgi?command=show_page&Catalog_Name=928_USA_83_86_KATALOG&Illustration=901-00&Line_Item=27

928 questions

Danglerb · 03-30-2008, 03:01 PM

Quote:

Originally Posted by Randy V

The 'green wire' is present only on older non-brain cars - i.e. - '78 - '81.

Hmmm, substitute "something like what a green wire does"

86porsche · 03-30-2008, 03:04 PM

I think you could be on the right track alrite danlerb. but wouldnt I be able to see if someone before me had ran a jump from the pump up. I havnt seen anything there but i have seen someone was at the switch wires which leads me to believe there was a problem there before i got the car. this thing is driving me mad!! i would appreciate if you or anyone else would explain the wiring at the back of the ignition switch so i could check this. I still cant count out the switch because when i got a new one iwhich fixed the problem of not being able to switch off the dash for a and then failed, so i sent it back thinking it was bad. the second new one has not solved it either. do you think my ezf or Lh brain could be toast?