02 sensor connector crumbles

[brett25]

hi I have an 1980 SC and the o2 sensor connector in the engine compartment broke apart. I wanted to splice a connector in to the wore but noticed its got a shielded core wire surrounded by what I assume to be grounding wire. Is there anyway to repair this? Is there a replacement segment of wire I can get.....help!

[DRACO A5OG]

Oh my, Welcome to the Club.

Unfortunately the loom is part of the DME wiring and it is cost prohibitive over $1300, if you can get it.

I and many have just solders a shielded/water proof bullet spade M/F. The most important part is the solder at the DME side, make sure it is solid then shrink wrap it.

Some have stated the connector is also a air sampler which effect the proper function of the O2S.

Jim

[CharlieB]

No DME or DME loom on an 80SC!

[DRACO A5OG]

Doh, you right I meant on 3.2. my bad. Well maybe it will be less expensive then.

[brett25]

ohnooooooooo! my mechanic said he can fab up something. Do you think its doable?

[DRACO A5OG]

Probably going to do the Bullet Spade Trick or at a minimum stand spade. Hell, you paying him to do that? Hope not?

[brett25]

well, Draco, im pretty handy, but im not sure about the hookup. I mean how do i keep the ground wires from contacting the innter signal wire? I put in a spade connector already, but Im afraid its not right, as all the wires are mashed together. How did you manage it?

perhaps the outer wiring is the air sampler? or is it a ground?

[DRACO A5OG]

Heat Shrink it Brother!


BRB, will post a pic

[brett25]

lol, i mean how did you manage the wires? did you solder all that mess together, or did you separate the signal wire from the outer wires?

oops just saw your BRB, ok thanks!

[tirwin]

Subscribed. Would love to know what you find. I was doing a tune-up last weekend and the same thing happened when I was checking the connector. I barely touched it. When I posted about the "orange" connector I was told that it was originally white in color so it has some age on it. Not too worried because the O2 sensor was reportedly disconnected anyway.

[GH85Carrera]

That same thing will happen to most mid-80s German cars. From what I found BMW & Mercedes have the same connector that turns to dust. I suspect VW and the rest of the German cars will have the same Bosch connector.

[DRACO A5OG]

LOL, soldered it.

It was a tight fit because my 3.2 O2 wire was too short to work on so it took me couple of tries to make a solid solder. As far as the wres, the 3.2 sensor and heating wires were designed seperately so I left the OEM heating conectors alone and just butt spliced the O2S side on to it.



Top is the Mercedes Logo-ed ( on the other side) heater connectors and the bottom is the O2S rig with water proof sealed bullet connector with heat shrink. I used the OEM connector metal clamp/holder to keep it where it should be.

I pulled it out a bit to show you the work.

[DRACO A5OG]

Originally Posted by GH85Carrera

From what I found BMW & Mercedes have the same connector that turns to dust. I suspect VW and the rest of the German cars will have the same Bosch connector.

Brain Fart, maybe the other German manufacturers sell the DME side connectors, we can dream right?

[brett25]

Draco, thanks alot for the pics, looks like very nice work. However the SC's have a different wire. Its got an inner insulated core inside an outer insulated bundle

[DRACO A5OG]

Post a pic if you can, like to see your set up.

Where you see the yellowish shield/tube use to be where the 3/8" OD OEM connector was. Underneath was the metal mesh shield. Liken to a coax cable.

I simply stripped it and the green outer layer away and solderd the Male Bullet and finished with Heat shrink. The O2S side I spliced the matching Female spade and finished it off with heat shrink for extra measure.

[brett25]

ah ok, i see, so you just cut away the outer wires and solder the inner core? I can do that, but are u sure your O2 sensor is functioning? I thought the outer wire was the ground, but I could be wronng

[DRACO A5OG]

Outer Wire? Do you mean the Mesh Surround? or the two white Wires?

My O2S does work, when I hook up the DVM to it with the car on I get .5-.6 volts, at hot running temps.

[brett25]

let me try to get a pic, but i would have to open up the work i did. On my application there is a green plastic shroud, inside that are copper strands and inside that is another small green shroud with a few copper strands inside

[DRACO A5OG]

Oh damn, don't want to mess up your work.

OK, so you have a copper mesh under the shroud, then green wire with 2 or 3 strand of wires?

One has to be the sensor feed (positive lead which draws current from the heat of the exhaust) and the others must be the heater feed/ground. The mesh I believe would be the air sampling on my 3.2.

Damn, hate working blind.

[DRACO A5OG]

This what mine looked like prior to fix:



Indeed the mesh goes back to the DME as a ground but strangely enough it terminates at the crumbled connector with absolutely no indication it grounds to anything. In fact, the Female shroud ( O2S Side) only receives the signal feed and nothing more.

It is however well insulated by the rubber shroud and crumbled plastic which was white in color in the beginning of it's life. Solved this on my mod with heat shrink, sorry to sound liek a broken record

Also did a bit more digging and found the "air" sample appears to be from the sensor itself as described in BOSCH's own cross section: