Electrical: Drivers door central locking wiring

[Jungle_Jim]

Hi all

The short section of wiring in the drivers door for the central locking - which connects to a grey 3-pin connector inside the door - is in very poor shape, with the insulation crumbling off in places. It seems to crack up in the areas which were flex pivot points - it's fine where it was held straight and stationary. Rare for a 240 this bit of wiring seems poorly thought out.

I am replacing the sections with some 16AWG flexible cable which I originally bought to make up the looms that go through the dreaded tailgate hinges (wire with lots of fine strands, so it's flexible and won't fatigue and break quickly), but this driver's door wiring has been more of a pain in the &%£@ than expected...

The original cabling in this central locking wiring is also a type of very fine, flexible cable (same stuff as used in the tailgate hinges). The strands are so fine that it's really hard to get solder onto. If you cut it at a point where it's bright copper it takes solder, but if it's had any exposure to the elements, once there's a small bit of oxide on it, you have to keep applying abrasives to make clean copper surfaces that will take solder and this gets laborious because there's so many strands.

My questions are:

1 Have others here had similar problems with this fine wiring stuff regarding splicing into it? Maybe crimping connectors would be a way to avoid the soldering difficulties, but with this door, there's not enough room for the sections of bulky, straight wiring that crimp connectors would cause. With wiring I usually prefer to solder then insulate with heat-shrink and tape.

2 Are there other areas around a Volvo 240 (mine's a 92 estate) with this or other types of wiring where the insulation perishes and disintegrates?

What a barrel of laughs this is turning into.

Thanks
John

[Clifford Pope]

I've had problems in the past with the tailgate wiring, but never, so far, with this aspect of the central locking. On reflexion I suppose similar problems might potentially occur with any wiring that connects something hinged to the main structure - electric windows, heated and remote-operated door mirrors, bonnet light, etc.

I did once replace the tailgate wiring with a proper loom, but it started to fail within a year or so. The problem there is that the wires are bent round a tight radius at the hinge, and fixed so that all the repeated bending takes place at exactly the same spot. It's almost designed to fail.

By contrast I've knocked up temporary (ie permanent!) replacements just using ordinary wires that don't try and go through the hinge but just hang freely in a loop about 4" diameter. It's not as neat as the original but it lasts indefinitely.

The secret is to take the flexible section in a curve of the widest possible diameter, with the fixing points contrived so that the wire coils and uncoils smoothly without any sharp kinks.
Electrical connections to the engine largely do this for example - the wires to the crank position sensor, oxygen sensor, all the other innumerable high and low tension connections allow as long a length as possible for the wires to flex in.
Forcing a wire to bend repeatedly over a short length is a recipe for it's failing.

[Jungle_Jim]

The wiring in the drivers door doesn't even have to repetitively bend, it just has to take a bit of vibration and minor flexing - but it seems that the type of cable used had insulation which wasn't long-lasting (if you can call failure at 30 years that!)

I know this is about door wiring - but - moving to tailgates - I also bought some new harnesses for the tailgate, but decided to not use them because they seemed too rigid and bound to break. So I sourced some wire online, which is designed to flex, has silicon insulation so petroleum-based lubricants won't affect it, and is 16AWG, which is thicker than the original stuff. Five years so far and still working fine. I am using this same wire for the drivers door central locking and any similar job.

This wire https://www.ebay.co.uk/itm/363330386...Cclp%3A2334524

[Othen]

Originally Posted by Jungle_Jim

Hi all

My questions are:

1 Have others here had similar problems with this fine wiring stuff regarding splicing into it? Maybe crimping connectors would be a way to avoid the soldering difficulties, but with this door, there's not enough room for the sections of bulky, straight wiring that crimp connectors would cause. With wiring I usually prefer to solder then insulate with heat-shrink and tape.

2 Are there other areas around a Volvo 240 (mine's a 92 estate) with this or other types of wiring where the insulation perishes and disintegrates?

What a barrel of laughs this is turning into.

Thanks
John

John,

The engine bay loom on older 2XXs has particularly poor insulation. Here is the solution I used for the RB:

https://www.volvoforums.org.uk/showp...postcount=1260

Alan

[Laird Scooby]

Originally Posted by Jungle_Jim

The original cabling in this central locking wiring is also a type of very fine, flexible cable (same stuff as used in the tailgate hinges). The strands are so fine that it's really hard to get solder onto. If you cut it at a point where it's bright copper it takes solder, but if it's had any exposure to the elements, once there's a small bit of oxide on it, you have to keep applying abrasives to make clean copper surfaces that will take solder and this gets laborious because there's so many strands.

Your best course of action is to follow the loom back into the car John, at some point it will have a multiplug, the terminals will almost certainly be crimped with what is often referred to as a "W" crimp. The terminals should be available from Volvo still, if not an autoelectrical place should be able to source them for you.
Replace that section of loom completely with your new cable and terminals.

That's the ideal solution, alternative solutions are to invest in some separate soldering flux, heat the wire up and dip it in.

It will sizzle and smoke a bit and the flux will clean the surface of the copper wire, allowing a good solder joint to be made - a variation on this is to twist your wire ends together as you would prior to soldering then heat the joint and apply some flux using a small flat screwdriver or similar tool that can act like a palette knife.

Continue heating then add some solder to the joint. Clean off any excess flux with some IPA as it is corrosive and may eat the cables otherwise.