Wiring Looms

[Lotus fan]

I am rewiring my Plus 2 and have bought some new looms for it.
Regarding Brian Bucklands recommendation (page 518 of his book) to add a fuse between the solenoid and loom (to test/protect it).
Which terminals on the solenoid and loom do I connect the fuse to?

Regards

Ian.

P.S. you probably think that if I have to ask this question then I should'nt be rewiring it !!
But I'll give anything a go

[alexblack13]

Hi,

I think you are referring to Brian's temporary 10 amp fuse fitted to the connection (Thick brown wire for easy descript') which carries the power from the battery to all of the car's electrics. This is taken off the solenoid. Brian has a fuse link ass'y made up which gives protection to your new loom when first powered up. Any mistakes or faults will just pop the fuse.

The fuse link ass'y Brian showed had Lucar (35amp I think) push in terminals on both ends. One male and one Female which just linked from the solenoid into the main (Brown) feed. The main power carrying cable which comes direct from the battery is bolted onto the solenoid via (I think) a 3/8" ring terminal, below which is fitted a male 35amp Lucar terminal onto which the loom main feed (Thick brown cable) is attached. Push the female end of your brand new fuse link ass'y onto this connection and then push the male end of the link into the loom connection. You now have a fuse protecting all of the circuits on your car's newly fitted loom. If it goes POP when you connect the battery and power up for the 1st time, then you have a fault. Much better than destroying your new loom or indeed your car.

I might have some of the tech-spec wrong but basically that was it.

Hope this is helpful and good luck.

Alex B....

[Lotus fan]

Thanks for that Alex

It says a 20A fuse but I s'pose that if it doesn't blow a 10A then even better !!

Cheers

Ian.

[jono]

Ian,

Have fun with the dash , and if the loom has straight Lucar connectors make sure you change them for flags.

Also, don't assume that the looms are free from error - eventually found 2 on mine which had me chasing shadows for a whole weekend 2 of the multi connectors had pins which were transposed).

This was on CN loom which was otherwise of good quality.

Just been through this and the dash can be a challenge to say the least - I ended up unpicking the dash loom and splitting it into 3 separate legs to assist in installation - it's very, very tight behind there.

If your looms are made in modern thin wall wire then it will be much easier - mine were old thick wall wire of around 20 year vintage but I guess the purists would approve.

Jon

[ricarbo]

Jono, What's a flag connector and how is it better?
Regards
Richard

[stugilmour]

Richard, a Flag connector puts the wire at 90 degrees to the female terminal. For the Plus 2 it is advisable to use these on the dash switch terminals, particularly along the bottom row. This is because the clearance is so tight to the heater box.

Here are some examples, I can't recall if I used this exact style. I recall having to use the nose portion of the crimper to attach the flag, which is not as easy or secure as a regular spade type.

http://www.autoelectricsupplies.co.uk/product/4

You will want these as well. Remember to slip them on the wire before crimping on the flag. If you forget, you gradually cut the wire too short.

http://www.autoelectricsupplies.co.uk/product/6

For the `damned the purists`approach, I did not use bullet connectors for the major junction points in my re-wire, rather I used ones like this

http://www.autoelectricsupplies.co.uk/p ... category/7

For sure invest in a really good crimping tool and wire stripper.

Here is a link to another really good on line supplier for this stuff

http://www.vehicle-wiring-products.eu/V ... mepage.php

Good luck with the project. You can do it! I had never done a project like this and it came together very well. just triple check everything as you go. Do you have the loom(s) and dash out of the car and spread out to figure it all out?

HTH Ask any questions as you go and its not that bad.

[alexblack13]

All good advice.. I would add..

Solder all the connections too. I took out all the bullets and hard soldered the lot except a few behind the glove box and what do you know! One of them, the big 35amp bugger failed on me. It is now a big fuse link and it too is soldered in.

And I prefer hear shrink insulation. But to each there own.. As I am always saying.

Alex B....

[512BB]

And just a warning to all ELAN owners who are rewiring.

A friend of mine bought a new loom from one of the usual suspects, stating that it was for a late Sprint with an alternator. The labelling on the packet it came in, indicated the same.

However, on fitting the loom to the dash, it became obvious that the loom was made for an S4 with the ignition switch on the dash, and not made for a Sprint, with the switch on the off side of the column. Result, all associated wires were to short to reach the switch. He was NOT happy. All said wires had to be cut and lengthened by 8 inches.

So be careful out there in Lotus land. Check your new loom as best you can before trying to fit it.

Leslie

[jono]

...if a picture paints a thousand words

[ricarbo]

Thanks, Jono, I thought that was what you meant, but didn't know they were called flag connectors.
On Alex's point of soldering, I have a comment. I used to solder these, but no more. The reason is that I learnt from my model aircraft chums that soldering makes for unreliable connections of wires to terminals. This is because the solder invariably wicks into the cable, meaning the cores of the cable become as one and therefore inflexible, for a short length. The cores are then liable to fracture at the transition from flexible to rigid, caused by vibration. A normal Lucar connector has two areas to be attached, one for the bared cores and the other for the insulation. You should ensure that no wicking extends into the cable as far as the area where the insulation is attached, but this is, in practice, impossible. So crimping is better for both attachment points. With a machine made properly crimped connection, the cable cores are pressed so hard on to the connector that a pressure weld occurs. To get near this you will need a good quality ratchet crimper, ?20+, the cheap ones like a modified pair of pliers, for about ?5, just won't do it however hard you squeeze. The jaws of ratchet crimpers vary, according to the terminals they are meant for, so you need the right one for the job.
Having made up the cable ends, I always smother them in Vaseline before plugging them in, to keep out moisture and so prevent oxidisation. i use it in the bulbholders, too.
Bullet connectors I find a pain. They have no method of attaching the insulation, so there is once again, the unsupported transition from rigid to flexible and the female parts corrode, so Vaseline is even more important.
Regards
Richard

[Bud English]

The cores are then liable to fracture at the transition from flexible to rigid, caused by vibration.

It's for this very reason that connections used in aircraft wiring are crimped, not soldered.

... So crimping is better for both attachment points. With a machine made properly crimped connection, the cable cores are pressed so hard on to the connector that a pressure weld occurs.

The terminals you use make a huge difference as well. The bulk of terminals sold here in US auto supply stores are junk. Make sure you get terminals that have a secondary crimp area that grips the insulation as part of the crimping process. I like the ones that actually have a secondary metal band under the plastic.

I would second the recommendation to buy, beg, or borrow the best crimpers, for the terminals that you're using, that you can. When properly crimped, in a pull test, the wire will break somewhere away from the terminal before the crimped connection fails. If you are new to this, it might be a real eye opener to actually make a few test connections and pull them until they fail. If the wire pulls out before the wire breaks have another look at your process.

Disclaimer: ...although not a real live electrical engineer, I have made thousands of wiring harnesses and cable assemblies for aircraft, cars, and boats, both in the military and in private business.

[MickG]

Bud English wrote

Disclaimer: ...although not a real live electrical engineer, I have made thousands of wiring harnesses and cable assemblies for aircraft, cars, and boats, both in the military and in private business.

I've been a real live electrical engineer a couple of times, it's bloody painful.

Sorry couldn't resist it

Mick G

[Bud English]

Too funny! I've been an electrical conductor a time or too as well.