Resetting a wiring loom back to stock?

julianf · Jan 5, 2017

So, ive eventually got the loom (bulkhead and front of car) off my 300tdi 110.

Its not too bad, however, there have been some modifications. I think the truck had a flashing beacon etc on it prior to my ownership.

Anyhow, theres some melted fuses, some splices, and (i think) some relays that are non-standard.

Some photos below -

Overall, its far from terrible, but it needs some attention.

Ive purchased a replacement blade holder (PRC4826) and will start going through things, but, if anyone knows, just by looking, whats going on, id be glad to hear it!

Thank you.

stewd · Jan 5, 2017

Chop it all out and re-wire the lot is the best idea, especially as its previously had fuses melt.

AMR2341 relay (Red) is wiper blades
Black relay next to it is the indicator relay
Looking at the 25amp fuse and the white wire and white and orange (both these are ignition / Auxiliary) coming off it, it splices into the ignition to supply power to something. Where does the purple wire end up?

julianf · Jan 6, 2017

stewd said:
Chop it all out and re-wire the lot is the best idea, especially as its previously had fuses melt.

From the inspections that i have made, i can see no further damage. Ive split apart some of the bundle, and no sign of melting and / or abrasion.
The loom was taken from a working system (removed due to bulkhead swap) and there's no real reason why, if it was refitted in an identical way, it shouldnt continue working.

...which makes me reluctant to follow that specific bit of advice! : )

From what i can gather, the oddities round the back are re-wiring of the melted sections. I can not understand why the fuse holder itself has melted, whilst there appears to be no damage to the wires, but i can only go with what is before me. Of course, the very purpose of fuses is to protect the wire, but to get them to give off that much heat, you would assume somthing was amiss.

With regards to those three wires -

White goes to fuse #8
Purple is actually PG, so, i assume, the blower motor (will check with multimeter later) which would make sense, as its own fuse (#5) is otherwise missing.

The one that's currently causing me more confusion is the red jumper comming out of, what i think is, the alarm connector (not in use) and going to the flasher relay.
This one -

stewd · Jan 6, 2017

What pin does that red wire go to? If it's 49a then it would be to flash the indicators upon alarm setting / activating.

Makes sense if fuse #5 has melted (standard a 15amp fuse) to then be spliced in with a 25amp so the Heater would work.

Personally I'd have a look at the heater blowing if it is damaged or not, if you have one put a power probe to the motor and see if it spins correctly, if seized this would cause the fuse to get hot and in your case melt.

The fuse below this one (#15) is your left hand side lights, which shouldn't melt but might of been caused by the damage of the heater fuse above it, and the one to the right of is it your right hand side lights which is also missing. Double check these haven't been spliced in to the main beam.

Lastly all the fuses that are currently in are higher rated than what they should be,

julianf · Jan 6, 2017

Thank you very much - appreciated.

I do recall that the lights did somthing odd, but i cant remember exactly what. Somthing like sidelights being linked to dip beam, but i cant properly remember.

Thinking about this further - when i got it, one of the lights was out. I fitted one of those remote relay head lamp things, and found the issue with the side lights then.
But i also found that the light connector had been replaced with standard crimp terminals, so, possibly there was some issue at that end that caused a short, and the fuse to melt out.

I will be (re)fitting the remote relay thing (i forget who makes it, but its an off-the-shelf thing) so the headlamp loom wont actually carry any current when reassembled anyhow.

Ill check the pin on the relay that the red wire goes to. Im not aware of this vehical having an alarm or imobaliser. Ive found no additional 'boxes' anywhere.

The heater motor certainly spins (without power) as i have it off the bulkhead at the moment, but it may be that its knackered. Will investigate that.

Thanks again for your help.

I swapped over the fuse holders tonight - surprisingly it didnt even take too long -

(half way through)

Tony e · Jan 6, 2017

All looks a dogs dinner, fuses blow when over loaded, if the holder melts this is a gradual overload that might not blow the fuse, start with the basic electrics with the correct fuses for that circuit, rip out the non standard alarm system and start again

julianf · Jan 6, 2017

...what non-standard alarm system?

I cant see any alarm system at all!

(or do you mean that [single] red wire?)

Tony e · Jan 6, 2017

Some were in its history its had an alarm otherwise why the extra wire to the flasher relay

julianf · Jan 6, 2017

Maybe so, but i said previously that i could find no alarm boxes, and you're telling me to "rip out the non standard alarm system"

Basically, so far as i can see, there has been a melting issue, for reasons unknown, and a not especially neat fix applied. And the red wire to the flasher relay.

Tony e · Jan 6, 2017

The melting issue is the main concern so work forward to what it actually powers and see if it is being over drawn

stewd · Jan 7, 2017

Looking at the Red wire into the indicator relay, It goes into "49" which is the permanent power supply to the relay, This is Live even without Ignition.

Good idea on the remote relay, especially if your wanting to put higher rated headlights / bulbs in.

Also what colour wire it the red connected to in this picture? (Attached) Also what other wires are coming off the block?

julianf · Jan 7, 2017

Red is going to thin white orange.

Other wires are thin brown light grey, fat brown, and medium brown orange.

On the relay, the red jumper goes to the same terminal as green (medium diameter)

Other wires present are thin green purple, thin black, and medium green brown.

Thanks again of your interest!

julianf · Jan 7, 2017

PS by thin, medium, fat - I mean diameter of wire, nothing to do with colour code!

stewd · Jan 7, 2017

Weird.....

The colours you have given are all related to ignition / constant 12v feed, seems it's sending power down the white/orange for some reason, trace that cable to see where it ends up (should be at ignition Barrel) if I remember correctly white/orange connects to Ignition Aux 2.

As a suggestion I'd loose the extra fuse (25amp one) and wire the heater back in properly.

Resetting a wiring loom back to stock?

julianf

Well-Known Member

stewd

Active Member

julianf

Well-Known Member

stewd

Active Member

julianf

Well-Known Member

Tony e

Well-Known Member

julianf

Well-Known Member

Tony e

Well-Known Member

julianf

Well-Known Member

Tony e

Well-Known Member

stewd

Active Member

Attachments

julianf

Well-Known Member

julianf

Well-Known Member

stewd

Active Member

Similar threads