Cable connections

[Martin Erhard]

My solenoid ‘battery’ terminal is used also to connect three brown power leads with the main thick red lead from the cut off switch. (Are they all wired like this?)This is an awful position for this connection, the brown cables are brittle from the heat and one has now broken off.

 

I want to move this connection away from the solenoid by cutting back the brittle sections and reconnecting the thick red cable with the three brown cables. (I will run the starter from a separate short cable direct from the battery - this will be the one thing then not controlled by the master switch).

 

What is the best /neatest method of joining thick battery lead with three other cables of different thicknesses? A junction box of some type? These thicker cables are always a bit of a pain to crimp/solder terminals to.

Any suggestions welcome please.

 

[j passfield]

Hi Martin, as with a lot of jobs there is really only one way to do it properly, when it comes to electrics the only "real" way is to make soldered connections. The secret is to use a "bloody great old fashioned " iron, the run of the mill soldering guns and gas heated ones just don't produce enough heat. You could also invest in some serious quality crimping tools, check out someone like "Vehicle Wiring Products" website, but the cost of these will probably outweigh taking the cables to an auto -electrician and getting them to make the crimps for you. Junction boxes and the like tend to give problems after a while especially when dealing with heavier loads. Hope this helps!

[Bricol]

And then the opposing view . . .

 

I used to solder joint too, then quite a number of years ago, a mate who worked for Lucas Aerospace told me that they didn't solder wiring looms for fighters etc because the soldered joints always failed due to vibration just at the point where the solder stopped where it penetrated down the wire.

 

If it's good enough for fighters, it's good enough for me - so all my joints are crimped, with the proper tool, after having slid a suitable length of heat shrink down the wire so once crimped, I can slide it back up and shrink it over the end of the terminal, sealing it and adding a bit more support so the cable outer can do it's job - protect the conductors inside.

 

Not had any fail due to vibration or corrosion in over ten years and some of my trials cars get some serious off-roading abuse.

 

Bri

[Martin Erhard]

Thanks very much chaps I really do appreciate your help. I did'nt mean to start a crimp v. solder debate - really just how to join this lot together. For instance I could just crimp/solder a ring terminal to each cable, connect with nut a bolt and wrap in insulating tape It would work but there must be a proper way of doing this...

[Johnty Lyons]

On cars without a cut off sw these all come as on most tin tops from the Battery+

The fitment of a cut off sw makes their location difficult You only can take them from either the sw itself or from the other end of that cable which is now the solenoid.

If you don't want to take them from solenoid your faced with a cut and shunt operation no matter which end you approach it from.

I suggest you run a single brown 60 strand from alternator to solenoid that takes care of the high current. Then take a 44 strand from the cut off sw to splice into the other browns

Crimp ends fed into a joint box .... Crimp first then solder and cover with heat shrink Thre are lots of suitable jcn bxs on VWP web site.

 

jj

N.I. L7C AR 🙆🏻

Membership No.3927.

 

[bobt]

Hi,

 

If you don't have a big enough iron I've used a plumbers torch before to solder large battery style terminators. Don't put the whole terminator in the flame or you could burn the cable insulation. Just put the tip in the flame and wait 10-15 seconds for the heat to soak into the rest of the terminal. Solder can then be fed in as needed. If you don't have a plumbers torch (10 quid) you could also use the ring on the gas stove. Rember tho you only need to put the tip in.

 

Rob

 

 

 

Edited by - bobt on 14 Oct 2007 20:44:12

[Martin Erhard]

Thanks Johnty

That makes sense - I hadn’t realised the thick brown wire was the alternator feed into the system rather than power out. So I need to connect this to the battery either via the solenoid connection or direct to the battery terminal itself - which would eliminate any further exposure to heat. Then I can replace the thick red wire from the cut off switch with a smaller cable to connect to the other two brown cables using a simple box with managable size connections . Excellent!

Thanks very much.

Thanks Bobt for the soldering advice also.

 

[Johnty Lyons]

be very carefull you cant take the alternator cable to the battery IF youve got a cut out sw otherwise it wont cut the engine in an emergency You can only take it to the solenoid and the solenoid will be fed from the cut off. If thats how its wired the cut off must completly isolate the battery and its charging current from the car. Hard to put into words but dead easy when your looking at it.

 

jj

N.I. L7C AR 🙆🏻

Membership No.3927.

 

[Martin Erhard]

Johnty - thanks again - yes of course the engine would run on driven by the alternator. Sorry, I have to get my head around auto electrics in general but Caterham wiring leaves me more baffled than most.

 

This all started when I removed the solenoid to resolder the terminals. This I am pleased to say seems to have cured my 'click' problem but having disturbed the brittle connections they became loose. Having all these cables joining on the solenoid millimeteres from an exhaust primary does not make much sense.