help with underhood wire identification

[jimk]

Coil power is not supposed to be fused!  Never was and only if you wanna sit in the rain some night wondering why the car stalled.

[AustrianVespaGuy]

2 hours ago, esty said:

another question...where do the black wires connected to the starter solenoid originate from

Ok, so we need to be a tad careful here because sometimes 70's Germans were really clever with their electrics and other times they were really dumb. If it's coming from the positive side of the starter solenoid, then it should go to the positive side of the coil.  This is help make sure the coil sees FULL battery voltage (bypassing the original ballast/resistor wire) while cranking.  But as your already know they also used black for the negative side of the coil, and from the points to the tach. So. . . black to positive and black to negative. . . yeah this was one of the dumber ones! Again not sure why there's TWO wires either, so double check before plugging in (should only see +12v when cranking, otherwise nothing).

 

1 hour ago, John76 said:

The late '72 and '73s did away with the air pump, but kept the EGR and added the speed relay/white electromagnetic valve and dashpot.

 

My money is on this one, for two reasons.  Green/Red is a very 'unusual' color for 2002 wires, which makes me assume it was something added specially for American/California market cars. Secondly, although the green/red is different, everything else about it looks just like the (now long gone) speed relay on my '75's diagram, with the two brown and black terminals on one side, power in the middle, and output(s) on the other side.  (This 75 one only drove one silly little valve, with two others driven by 'other' things, but your 72 could easily have had two, both driven by that one relay). I still advocate: Trace it, then Trash it!

 

[esty]

i just had steve send me a pic of the back of the fuse box...as far as i know, him too, the fuse box was never tampered with after we got the car...it's wired the way we got it as a running driving car with a bent nose panel

 

tomorrow i will follow the wires on fuse 12 and see where they all go...from looking a few days ago i know one of those pink wires goes to what John id'd as the horn relay...

 

but as you can see there is no green wire on fuse 12...the double green wire we've talked about below it is on the lug below #12, and controls fuse 10 &11...i can easily add a wire to fuse 12 or move the green wire from fuse 11 up to fuse 12...mt big laminated, colored wiring diagram does not show a green wire to or from fuse 12

 

the diagram show 2 ganged green wires from fuse 10 going to #15 on the ignition switch and the other to the test/diagnostic plug...it show  2 blue ganged wires from fuse 11 going to "HT IGNITION SYSTEM RELAY" with the other blue going to pin 5 with the cluster wires

 

the diagram shows a grn/rd wire from coil + to ballast resister with the other end of the ballast resistor being a blue wire going to the same pin as above at the "HT IGNITION SYSTEM RELAY"

 

fuses 11 & 12 in box -

 

fuse 12 has 3 pink wires...fuse 12 has the 2 green wires we've discussed that aren't going anywhere under the hood

 

 

looking at the pictures of the fuse box steve sent is making me wonder...notice the paper board colors under the fuses, purple, green the red...are the colors an indication of hot, switch, etc...if so then i would say that fuses 10 and 11, the green section are hot all the time and i assume the next, red slot is the power in from the battery

 

 

sorry for the long post..

 

lifted the fuse box to try and run down some of these wires..the 1st thing i found was a ganged larger green wire that had fallen off...that wire, 3 wires together, 2 green wires and a smaill black wire...the large green wire goes to the ignition switch, the emall green to the diagnostic plug...the black to something i've never seen that looks like a condenser that's fastened to the body in the bottom of the fuse box opening...

 

the red wire from fuse box goes to ignition switch and diagnostic plug fuse 12, pink wires...the larger pink wire goes to ignition switch...one small pink/blk wire goes to what was id's as horn relay, the other small one goes to what i think is the flasher mounted under the dash above the hood release

 

good thing we lifted the fuse box, the car would have never started with that green wire laying in the bottom of the hole...does it matter which spade it is connected to in the fuse box, next to the other green wires which are connected to fuse 11, not fuse 12

 

Edited July 20, 2021 by esty

[ray_]

Esty that relay is what serves to limit coil voltage in the circuit during running and allow 12v during cranking.

 

I'm not running it because I have a 123 dizzy.

 

Here's mine on the '73.

 

The rest of you people... ... ;-)

Edited July 20, 2021 by ray_

[esty]

29 minutes ago, ray_ said:

Esty that relay is what serves to limit coil voltage in the circuit during running and allow 12v during cranking.

 

I'm not running it because I have a 123 dizzy.

 

Here's mine on the '73.

 

The rest of you people... ... ?

Ray, is it necessary to get the car running?...if so i need to trace the wires and it has a couple of loose wires plus that on terminal with a connector without a wire

 

[ray_]

Yes if the car is wired as intended. 

 

You need to ensure you are getting 12V to the coil with the key in "run."

 

If that relay is unplugged and not bypassed, yeah the car will not run.

 

Cheers,

[conkitchen]

1 hour ago, ray_ said:

The rest of you people... ... ;-)

who you callin people? 

[ray_]

42 minutes ago, conkitchen said:

who you callin people? 

Not you.

 

?

[esty]

11 hours ago, ray_ said:

Yes if the car is wired as intended. 

 

You need to ensure you are getting 12V to the coil with the key in "run."

 

If that relay is unplugged and not bypassed, yeah the car will not run.

 

Cheers,

i'm not the brightest Ray, you say....yes it will but yes it will not.....if i leave the relay thing like it is or remove it and wire the coil and dizzy as discussed should the car start and run...how do i bypass it, if necessary...

 

 

 

 

[ray_]

I'll need to read the thread again after lunch but the relay allows 12v when cranking and then switches the path thru the ballast when the key is in "run."

 

That's what the car wants. ☺️

 

I'll try to clarify better later today.

 

Cheers,

[jimk]

13 minutes ago, ray_ said:

I'll need to read the thread again after lunch but the relay allows 12v when cranking and then switches the path thru the ballast when the key is in "run."

 

That's what the car wants. ☺️

 

I'll try to clarify better later today.

 

Cheers,

That's it.  It's a normally open relay that when closed on cranking bypasses the ballast relay.  Coil was designed to run on less than 12v.  Battery voltage drops to around 10v when cranking.  So in reality the coil is only operating on 10v while cranking and while running.

EFI logs tell the battery voltage story, not just a guess.

[esty]

54 minutes ago, jimk said:

That's it.  It's a normally open relay that when closed on cranking bypasses the ballast relay.  Coil was designed to run on less than 12v.  Battery voltage drops to around 10v when cranking.  So in reality the coil is only operating on 10v while cranking and while running.

EFI logs tell the battery voltage story, not just a guess.

i don't have a ballast resistor, i'm using a blue coil with electronic ign in dizzy...can i toss that relay? i couldn't say that it was ever connected when we got the car...i would have marked it it it was something i thought needed to go back where it came from

[ray_]

31 minutes ago, esty said:

i don't have a ballast resistor, i'm using a blue coil with electronic ign in dizzy...can i toss that relay? i couldn't say that it was ever connected when we got the car...i would have marked it it it was something i thought needed to go back where it came from

Edit: I'm going to defer to those smarter than me.  I don't know if 12v (no ballast) will overheat the coil when running electronic ignition, or if you'd be ok just running 12v thru the ballast with your ignition (dropping the voltage).  The latter would be safer.

Edited July 20, 2021 by ray_

[conkitchen]

13 minutes ago, ray_ said:

Edit: I'm going to defer to those smarter than me. 

you mean people? 

[AustrianVespaGuy]

2 hours ago, esty said:

i don't have a ballast resistor, i'm using a blue coil with electronic ign in dizzy...can i toss that relay?

Firstly, big thanks to @ray_ for solving the mystery! Life's a real bitch without the right wiring diagram; anyone know what happened to all those great ones that *were* available on the 2002tii.org site?

But to your question @esty, o you don't need any sort of ballast resistor with the blue coil, it has enough internal resistance that it can live with 14v from the battery all day long. So if you run/use a wire that comes from the hot side of the fuse panel (so really straight from the ignition switch) to power the coil, then no you don't need to worry about that relay any more, and can just leave it out entirely if you want.  Maybe keep it if you ever think you'll switch back to the stock coil with ballast resistor, but I probably wouldn't!