Is it okay to use this connector?

[SteelGreyM]

Hey everyone.

When I was doing the removal of my engine I accidentally left one plug and it happened to break as I pulled it out of the car. It is the plug that goes in the coolant temp sensor in the cast coolant line on the drivers side of the head.

I was able to get another plug from the junkyard from a non M e46. It’s keyed exactly the same and fits perfect. My plan was to solder the wires from my harness to the new plug. My question is doesn’t it matter which wire goes on which side? Or is it simply a resistance based circuit like the outside temp sensor where the placement of the wires does not matter. If pictures are needed I’m happy to provide.

Thank you

[Arith2]

It shouldn't matter as I believe it's just an NTC. The hotter it gets, the less resistance. Maybe attempt to do it the right way if possible.

[eacmen]

Hey everyone.

When I was doing the removal of my engine I accidentally left one plug and it happened to break as I pulled it out of the car. It is the plug that goes in the coolant temp sensor in the cast coolant line on the drivers side of the head.

I was able to get another plug from the junkyard from a non M e46. It’s keyed exactly the same and fits perfect. My plan was to solder the wires from my harness to the new plug. My question is doesn’t it matter which wire goes on which side? Or is it simply a resistance based circuit like the outside temp sensor where the placement of the wires does not matter. If pictures are needed I’m happy to provide.

Thank you

Instead of soldering the wires I would use the waterproof heatshrink with the solder in it that you use a heat gun on. In my experience normal solder joints go bad pretty quickly. These end up stronger than any solder joint i’ve ever done with a soldering iron.

I love these things:

120PCS Solder Seal Wire... https://www.amazon.com/dp/B07S62KYSL...p_mob_ap_share

[sapote]

In my experience normal solder joints go bad pretty quickly.

Using acid base flux could lead to this issue, but using resin flux core solder should be very reliable, as it was used for DME and other circuit boards in the car.

OP, the Brown wire to pin2 and Brown/Red to pin1.

[eacmen]

Using acid base flux could lead to this issue, but using resin flux core solder should be very reliable, as it was used for DME and other circuit boards in the car.

OP, the Brown wire to pin2 and Brown/Red to pin1.

I am able to make very good solder joints on a PCB with no issue (this is something I do on a regular basis). But when joining two wire ends that have a large thermal capacity is difficult for me to make a good joint. Especially for cables that might need to bend. And with the wire harness on the car its even more difficult.

[Arith2]

I'm not sure about BMW but Porsche says DO NOT solder any wires. I can imagine BMW feels the same way. Use the wire connectors that clamp the copper wires.

Use these

https://www.fcpeuro.com/products/bmw-cable-connector-61138353746

[sapote]

I'm not sure about BMW but Porsche says DO NOT solder any wires. I can imagine BMW feels the same way. Use the wire connectors that clamp the copper wires.

Interesting about not to use solder on any wires. If we look at the BMW battery fat cables, the bolted down terminal connector was soldered to the cable in addition to be crimped.
The only reason I can see why factory don't recommend to use solder on wires is that lack of strain relief the soldered wire is stiff at the joint and can break easy when moving around. .

[eacmen]

I'm not sure about BMW but Porsche says DO NOT solder any wires. I can imagine BMW feels the same way. Use the wire connectors that clamp the copper wires.

Use these
https://www.fcpeuro.com/products/bmw...or-61138353746

I would rather use Posi Lock connectors. The tool to crimp those correctly is pretty expensive. Ive used a generic ebay crimp tool with some success but with the smaller wire it gets very difficult to do correctly without the correct tool.

[sapote]

But when joining two wire ends that have a large thermal capacity is difficult for me to make a good joint.

Yes, heavy gauge wires need to be heated up with heat gun for a good "wet" soldering joint.
In this case for the small wire for the sensor, I don't think it's the issue.