JosephK

Back to my '87 924s electrical no start puzzle after months of mothballing. (X-post apologies - also posted on PParts forum but I'm getting desperate)

First question: Can anyone link me up to a wiring harness diagram for the car?

I have a dead short to ground on the disconnected Black/Green (SW/GN) wire at the fuel pump. I'm trying to find out why. The wiring diagram sheet 7 references something called the "CONNECTION PLUG REAR" at grid mark 57-F but for the life of me, I can't physically find it.

So, my second question is, where is this "CONNECTION PLUG REAR" connector physically located? The diagram shows it as a 2 prong detachable connector with both legs on the pump side coming from a Y split on the SW/GR line from the pump (and whats up with that?). Then the wiring diagram shows from the other side of the connector, single wire exits it to the #2 fuse. But, it splits again at the fuse - one wire going directly to the firewall DME 9 pin connector and thru pin #4 to O2 sensor (gonna check this tomorrow), the other wire goes thru the fuse #2 to the 87b prong of the DME relay.

When I disconnect the DME 9 pin plug by the firewall and check the #4 prong SW/GR wire on the DME side - no continuity to ground. From the plug out to the mystery connector - SHORT TO GROUND with the RELAY in place and out. Hmmmm, looking like O2 sensor harness or other problem?

Now, I've traced the wires from the pump to the grommet and no connector. I've traced the wires in the interior from the grommet behind the rear seat on the passenger side. From here, they run under the carpet to behind the driver side of the rear seat and enter into the upholstery - no connector found, no visible wiring damage either. Any ideas where the mystery "CONNECTION PLUG REAR" is?

My third question is, where does this bundle that enters into the upholstry/carpet at the back seat behind the driver come out to get to the fuse? There are 8 wires in it so I don't know if it goes up to the DME plug by the firewall in the engine compartment but i have my suspicions.

So, the short may be O2 sensor circuit. But where's the connector?

Any ..... yes, any, clues would be very much appreciated and you will be venerated.

Thanks,
Joe

JosephK

A little help ...... please ...... anyone?

I've checked the O2 sensor wiring and it is a universal replacement and the wiring looks sound.

Still can't find the mystery connector between the fuel pump and the fuse....

A little help ...... please ..... anyone?

JosephK

WIN BIG - an all expenses paid trip to your refrigerator for a refreshingly COLD beverage of your choice!

Where is this "CONNECTION PLUG REAR" physically located in my car????

PLEASE HELP

JosephK

Nothing ..... ?

mel_t_vin

Joe, not sure how much help I'll be as I don't own a /1 car.

That said, from what I can gather [diagrams on hand], I suspect this mystery connector is situated in the cabin, under the dash, near the fuse/relay board. Have you tried to trace from F2 back towards the fuel pump? No sense in going the other way as F2 only goes to DME relay 87b.

Don't know if you've posted on any of the RL sub-forums, but, I haven't seen anything about your no-start issue. Can you give us a little history with events leading up to/and after your problem?

An engine requires fuel [at the injectors], spark [at the plugs], and timing/compression for proper combustion. During your no-start issue, what is missing? Fuel? Have you been blowing F2?