Oxygen sensor compatibility

waynej · Post by **waynej** » 23 Oct 2011, 19:15

Better to solder them and use heat shrink tubing over the connections. If you are in a humid climate the crimp connections corrode and produce resistance.

Post by **tjts1** » 23 Oct 2011, 19:32

waynej wrote:Better to solder them and use heat shrink tubing over the connections. If you are in a humid climate the crimp connections corrode and produce resistance.

In a hot environment where where its exposed to vibration a good crimp connector is the only way to go. Solder between 2 loose wires will crack and fail.

waynej · Post by **waynej** » 23 Oct 2011, 19:52

It is possible to make a bad solder joint but a proper solder joint is stronger the the wires and does not fail. With either method you need to secure the wires so they cannot vibrate. If there is enough flexing to do damage the wire will usually break before the solder.

turbozutek · Post by **turbozutek** » 24 Oct 2011, 04:04

Yeah I'd go with proper soldering every time too. And by proper I mean good solder, good iron and USE FLUX!

Then shrink it with some good quality heat shrink.

Chris...

Post by **tjts1** » 24 Oct 2011, 11:06

If you look at how every electrical connector is put together from the factory on your car, you'll find everything is crimped. If they soldered all the joints these cars would be a nightmare. If you look at any of the universal O2 sensors on the market they all come with crimp connectors on the end. Solder has no place outside of a PCB where the components are mechanically fixed to each other.

Post by **erikv11** » 24 Oct 2011, 11:56

I am not going to comment on soldering vs crimping but will offer this: there is a long history on the message boards of people having trouble getting the universal O2 sensors to work properly. There is no history of trouble with the plug-n-play sensors.

waynej · Post by **waynej** » 24 Oct 2011, 11:57

In the low voltage circuits (sensors) the factory keeps the # of connections to a minimum. There is usually just one between the O2 sensor and the ECU. Also the factory machine crimps use many time more pressure than we can produce and they squeeze equally all around instead of from 2 sides so they end up with no air space inside the crimp. If you insist on crimping, you can at least cover it with heat shrink and secure it so it can't flop around.

Post by **tjts1** » 24 Oct 2011, 13:00

waynej wrote:In the low voltage circuits (sensors) the factory keeps the # of connections to a minimum. There is usually just one between the O2 sensor and the ECU. Also the factory machine crimps use many time more pressure than we can produce and they squeeze equally all around instead of from 2 sides so they end up with no air space inside the crimp. If you insist on crimping, you can at least cover it with heat shrink and secure it so it can't flop around.

I have 2 engines running megasquirt with about 100 crimp connectors in each wiring harness without a single failure. If you want to risk cracked solder joints by all means you're welcome to it. All end to end wire joints are exposed to vibration and flex no matter how well you tie them down. Solder is not designed for this kind of environment.

Looks like amazon jacked up the price on the Bosch 13877 from $15 to $35 since I last looked at it. It was good while it lasted.

turbozutek · Post by **turbozutek** » 24 Oct 2011, 14:08

In a flexible cable, solder isn't stressed much d by vibration- it's only when you attempt to solder one solid object to another without supporting it that vibration based joint failure occurs. In the OP's case - joining a wire to a wire, solder will be placed under next to no vibratory strain whatsoever, as both parts can move in tandem. In fact, it's better for an application like this under vibration as there is no point of failure and the solder allows the shock wave to travel along the wire to its conclusion.

Crimping is a compromise based on cost, speed, labour and ease of repair and is actually more likely to fail when vibrated than a soldered connection as the cable is only supported over one part (the crimp).

In critical applications, like aircraft and military equipment, connections are often crimped for mechanical strength and THEN soldered for electrical integrity. Car makers are not interested in this approach however, as the labour cost would be astronomical!

I'd solder it personally, but then as a qualified SMT Rework specialist with 15 years experience, I'm biased I guess.

While the Bosch connector block is perhaps the best type of connector for this job I've ever seen, it IS still a hack and a cludge to allow Mary Jane Sh!t for Brains who doesn't know how to solder to do this job. It also looks fairly untidy, as space in that area is limited and very hot.

Just my .02 cents.

Chris...

waynej · Post by **waynej** » 24 Oct 2011, 21:17

tjts1, Where do you get the idea that solder is just for PC boards? Solder was used on wires including vibrating wires for about 100 years before PC boards!
I lived on the coast all my life until 14 years ago and I have replaced dozens of crimp connectors. The copper wire turns green and rots away inside the crimp. When I was a kid and learning to solder, I made some bad solder joints but after you learn to do it right it's usually a permanent fix.

Oxygen sensor compatibility

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