Meaning of “J/C” in wiring diagram

[Mmostowyk]

1987 Carrera. Trying to track down why ignition to start sends no signal to starter. I think I may have disturbed the alarm relay when I took out the wiper relay to clean.
Looks like the alarm system and DME work together. When tracking yellow wire on diagram it goes to DME, as well as a number of other loads, but it passes through a box labeled “J/C” as well. Is this an actual box? If so, where is it? There are several teferences to “J/C” in the power distribution schematic.
Any help appreciated.

[T77911S]

I have not looked at your diagram but you are only concerned about from the sw to the starter. if it goes other places that does not really matter.
I also don't think the alarm disables the starter, but could be wrong.

use a test light, at starter compare light at battery cable to yel wire when cranking.
if that is bad then check it out of the ign sw.
if the alarm relay has the yel wire on it check power in and out.
a MM can read 12v and there may not be enough power there to pull in the solenoid.

if it is an aftermarket alarm remove it. the solenoid needs a lot of power to pull in. aftermarket alarms that add in a relay just add resistance and a point of failure that can leave you stranded.

[Elombard]

I believe there is a way to ground out and disable the alarm/immobilizer At the plug in the frunk. I forget the procedure but I think it has been posted. Might allow you to eliminate that as an issue.

[76FJ55]

Don't have a wiring diagram in front of me at the moment so can't say how the starter trigger wire is run, but to disable the alarm, unplug the alarm module and install a jumper on the harness side between the two #61 connectors.

[steely]

Welcome!
I don't know what the "J/C" means (junction perhaps), but it is not an actual box, it is a multi-pole connector. Others have asked the same question.
The "50" may be a DIN reference to the starter.
The circled part below is the same electrical point in the schematic as in the Bentley.

*Sorry I don't know location



edit:
Your starter should respond.
Whether the car starts is another matter.
The Yellow start signal to the DME is used by the DME to send a signal to the DME relay in order to have the relay power the rest of the DME (but only when starting, DME running power is another step).
I think the Alarm messes with the Alternator but I am not sure either.

[aj88cab]

Just my SWAG....Junction/Connector?

[sugarwood]

[Rawknees'Turbo]

^^^

Ha ha Woody! What would J/C do?!

[T77911S]

start signal goes to my enrichment module on my 930, I assume(d) it may add extra fuel when cranking. it may do the same for the DME or as power like dan said.

go back to my original post.