355 Wiring Diagram Help

Hey Guys

I was cleaning and repining some connectors - and came across an issue. One of the two 12-pin rectangular connectors in the engine bay (near LH Rear shock) has a burnt wire. It is the connector with only 11 pins (one blank), and next to the F1 sensor plug - so I believe it is the F1 engine connector as mentioned on @Qavion's wiring diagram. It is the 3rd wire (full black) that is not part of a shielded set... So if I reading the diagrams correctly, it is the N-0.5 wire that goes to the Throttle Position Sensor (on the engine side)...

However, on the chassis side (where the burnt wire is) - the wiring diagram ends with 'SPLICE' - does anyone know where this wire terminates so I can check it / replace it as necessary?

Thanks

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Yikes....

Hopefully the two plugs haven't been mixed up. I heard you can melt half the car's wiring by doing this.

There seems to be some wiring colour variations in my diagrams, but pin 6 is definitely pink/black. This gives the following numbering:

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The damaged wire appears to be pin 4. That appears to go to pin 3 of one of the TPS plugs. Pin 4 is an earth wire, so somewhere in the harness there will be a splice or two. The earth wiring does end up at the TCU (pin 39).

I just noticed I have two pin 6's in one of my wiring diagrams. I've corrected it here:

https://www.dropbox.com/t/THBiVtvUDpo8L2r9

I recently amended an Instrument diagram for the F1 car, too, but it is still a work in progress.

Since the splice is not evident in your photos, I don't see what harm it would do by splicing in a short section of wire where the damage is. Is there enough wire to work with? One of those self soldering/sealing waterproof splices should do the job. Finding a new pin might be a little more difficult.

 

Let me double check this. One of my wiring diagrams says 38, another 39.

EDIT: The original two diagrams in the WSM also show different pins. In one diagram, pin 38 is unused and pin 39 is the earth. In another diagram, pin 38 and 39 are both used and both are earths.

 

How many strands of the conductor are damaged in that black wire? It looks like a low current application (5 volts). It may be possible just to wrap it up with black self sealing silicone tape if most of the strands are ok.

 

So if I reading the diagram and your comments above correctly, Pin 4 from the connector (chassis side) is an Earth wire that goes to Chassis Ground and Pin 38 or 39 on the TCU? A bit of the wire is damaged (copper strands broken) - so if it is indeed an earth, can I run a parallel extra wire directly from a closeby earth location to Pin 4 (and keep the current wire in tact/attached) - thereby just adding an earth/ground path ?

 

So why would an earth/ground wire burn the insulation off of it? I could see it if an external heat source damaged the wire. But this wire looks like it cooked its own insulation.

 

btw... Im looking at Fig12a F355 F1 Wiring Schematic

 

THAT is definitely something that I would like to know! The external insulation was intact so it was not an external source for sure

 

Assuming the pin numbering system is the same on the F1 plug and on the engine accessory plug (behind the left hand suspension strut), if someone mixed them up, that would put battery volts directly to earth. Pin 4 is the sense wire for the alternator.

Not surprised the wiring melted.

@huzilulu How long have you had the car?

Here's a diagram showing some of the wiring for the engine accessory plug:

https://www.dropbox.com/t/GfLRiTYtCAeAjHi0

(ignore the instrument wiring.... that's still being sorted for the F1 car)

 

I bought the car in October last year, drove it about 2 miles (from delivery truck to my garage) and then pulled the engine out for its major - its been a project for about 10 months now!

 

Also - I dont think anyone could mix up the 2 12 pin connectors because on the chassis side : one connector has female plugs, the other has male... so when connecting back to the engine it would not be possible to cross connect (unless they connected the 2 chassis plugs together)...

 

off topic - do you have the wiring diagram for the radio (original factory wiring?)

 

It's shown here, although I don't know if any car actually came with original factory wiring

https://www.dropbox.com/t/cHmFKoAb4W7WY4CV

Don't all cars have CD stackers?

Do you have a Sony head unit? Here's a Sony manual:

https://www.dropbox.com/t/P5xwpTVgpXsSwzF1

Also, a bus plug pinout for the Sony:

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So one side of the F1 plug is mounted to the chassis also?

For reference, the top side of connector 41019 supplies battery power to the alternator:

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The top side of 41019 has sockets.

Was it the F1 plug with pins that had the burnt wiring?

 

Yes, the burnt wire was on the chassis side of the F1 connector (Pin4 as mentioned above) ... The small 6 pin F1 sensor is 'mounted' to the chassis and the 12 pin connectors just hangs next to it off the same loom...

I am thinking that maybe at some point someone connected the F1 and engine connector without the engine (or during engine reinstall by accident?) - the engine connector has the big red power on pin 4 (for the alternator) and that might have shorted out the small black ground on the F1 connector...

I haven't been able to check the engine side of the F1 connector yet (engine is at H&S Motorsport getting a lot of love - top end and bottom end) to see if there is any wire damage on the other side of the connector.. that should help narrow down if the entire length is shorted (from TPS) or if just the chassis side connector wire is shorted...

Different issue:

I asked about the radio wiring because
1) The car came with an old school Kenwood radio (not Sony, so not original).. and the unit is basically dead (or mis wired)
2) There are apparently two 7 pin connectors (59014?) behind the radio that are partly connected each to the radio! The diagrams show one so I was wondering how the car was wired as try fix/remove the unnecessary wires...
3) The black connector is the Kenwood radio end

The big issue I am having is that it appears my IGN ON (blue wires in diagrams) are permanently hot - I noticed that the radio would not turn off after switching off the car the one time I drove it- nor would it turn off when testing a couple things in the garage before removing the engine (engine off, turn to ON/RUN (no engine start) and then turn off)...

I have measured continuity at the fuse box between some of the permanently hot fuses (27-28-29) and the IGN ON fuses (24-25-26) and they are all showing as connected... Even after removing Relay P (E12) (thought it might be a stuck relay) - it still shows continuity between all the above fuses... So I think I have a joint somewhere between the IGN ON and BATT/PERM hot wires... I thought maybe at the radio, but I need to figure this out....


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Also found this black box with a fused component in line of the power supply to the radio … any ideas what it may be ?
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The OEM diagrams never made any sense to me because there is no key power input.

Some of the wires on your two white plugs appear to be OEM, but I don’t know what the others are.

I haven’t looked at my Sony radio wiring for a while. It’s just a mass of cables and used/unused plugs. I would have to recheck them to see if there are two white plugs like yours.

Does all the rewiring seem to be downstream of the white connectors?

Do you intend keeping the Kenwood unit? (assuming it still works).

 

It is just a filter to prevent any "noise" in the alternator power supply from entering the radio. Most radios do not require this filter. One of my old school Sony radios had it (which I bought some 30 years ago).

 

Dug around the car and wiring diagrams - and your diagram is exactly how the car is wired up - well one of the 2 plugs atleast... There is no IGN ON on the factory radio harness... never was! Not sure how that radio turned on/off back in the 90s, but it didnt have an IGN ON for sure...

I will keep the Kenwood for now (other pressing needs at the time) but will swap it out in the next few months once I find a better unit

The rewiring is downstream of both white connectors (the second white connector is not connected to anything, and is just in series with the first) - maybe used on some F'cars for a secondary radio/unit?

 

What are possible faults to check for the cross between PERM Batt and IGN ON wires? There is continuity on my ammeter but it shows up with a resistance value of about 40-50ohms (and has a much softer beeping sound)

 

Where are you measuring the 40~50 ohms? At the Kenwood plug? Is that the black one in your photo?
Do you have a manual for the Kenwood unit which shows wiring? Where does the red wire go on the black plug? I see a small inline black plug going somewhere.

Are you doing the continuity checks with the battery cutout in cutout?

 

I’m checking at the fuse box with battery cutoff engaged (battery disconnected). Checked between fuses 27/28/29 and 24/25/26, which should not show any continuity since one set (27-29) are Perm Batt while the other (24-26) are ign on …

 

This is not a correct way to check whether there is any "leakage" between the PERM Batt and IGN ON wires. The devices connected downstream from the fuses 27/28/29 and from 24/25/26 create loops, via the ground, and you are reading resistance through these devices. The best way is if you use a small 5W bulb to see what you have on the lines having permanent and having ign. sw. 12V.