Car proximity sensor lead connectors.

[Davhill]

Hi,
I'm still struggling with this problem so I'm wondering if you electronics wizards can guide me.
I've added a set of reversing sensors to the rear of my car and here's how things are arranged.
There are four sensors on the rear bunper, connected by cables to a control box in the boot. The box has a power cable, another leading to the monitor on the dash and the four sensor cables.
These last are terminated with very small white plastic plus that fit into sockets in the control unit.This setup is working at the moment but I need to make some alterations as follows...

The sensor cables are very small (thins) coaxial ones and as it is a universal kit, most are far too long. The sensor unti connectors are so tiny and fragile, I want to use them as little as possible. I think the solution would be to find some male to female inline connectors to shorten the cables and for me to unplug should the rear bumper need to be removed.

The coax cable has very thin wires inside, silver-coloured inside nylon/plastic up the centre, copper mesh around the plastic. The OD of the cable is under 4mm.I am capable of soldering these cores to connectors.

I approached Farnell and RS about this but neither would recommend a particular product. I will also be adding four front bumper sensors and for this, I have four two-way 'tyco' connectors, which are claimed to be waterproof. This is because the forward connections will have to go under the bonnet.
Any ideas gratefully received. Thank you, DH

 

[Bluejets]

If I were you, I would leave well alone.

 

[Davhill]

Fair comment! It's what I get for buying Chinese.

 

[Bluejets]

Fair comment! It's what I get for buying Chinese.

I wouldn't say that.
It is the way of electronics etc. these days.
If you wanted to build your own from discrete devices, I'm sure you could find a chunky flex and plugs and sockets to match.
The way it is I can see you getting in way over your head and end up with nothing working and a rats nest for wiring.

 

[Davhill]

OK, thanks. I can give you some idea of what I'm facing.

This is the box of tricks a.k.a. control unit. It measures 98 x 71 x 31mm


And here's the full kit. Talking rats nest, you can see the amount
of cable the sensors have on them. The circular sensor units are 25mm diameter
and 18 mm deep.

In the boot, I could simply shorten the mini coaxes and use heatshrink appropriately. Or I
could simply let the excess wire accumulate in the corner behind the side panel. I'm
just concerned that tinning the extra thin wire cores might make weak points. It's
rather like PC connections in a less forgiving location.

Just musing, you understand!

 

[Bluejets]

Well aware of what you are trying to do.
The cabling does not lend itself to joining as for one thing it is extra fine, and secondly, not meant to be soldered in many instances.
Because it is so fine, it will eventually break due to the solder even under minimal vibration.
If you really want to "give it a go", you might be well advised to use a type of vero board to solder to and use cable restraints within perhaps an inch or so of the joints.
As well, it would be a good move to cover the entire joints and the now exposed central cores with a layer of ( would you believe) hot glue.
Works a treat on much of my RC gear.

Just had a UV eye unit I build for eye specialist here, returned with the (thin) power lead ripped out due to some splaw foot attendant.
The abovementioned hot glue saved damage to the main board and the restraint snapped the cable.
Was a simple job to cut back and reinstate the cable, all worked fine again.
Could have been a lot worse.

 

[Davhill]

Excellent, thank you Bluejets. In the light of your advice, I'll take the path of least resistance (pun intended).
There's a plastic panel that lines the left side of the boot and there's a large space behind it. I'll simply push back the excess cable and let it swill about out of sight out of mind. I will still have to deal with inline connectors at the front end because the cables run the entire 14 ft+ from the control box to the bumper. That's 4 x 2-ways. I have the Tyco m to f plugs so if I keep the tinning of cores as much in the plug pins as possible, that should help. Then, I can secure to cables to the inner wing before and after the joints with restraints. Decision made! Thanks again, much appreciated.

 

[Bluejets]

No worries.
That hot glue i mentioned has many advantages over other "restraints".
I used to use 5 minute epoxy BUT....when trying to remove/repair it was impossible.
This hot glue sticks like the proverbial AND it can be peeled back to remove quite easily.
Cheers....