Lucas 31270 Ignition Switch

[johnny2rovers]

I am changing my SIIA back to the original ignition switch and light switch configuration. I have seen the suggestion that the Lucas 31270 will not handle the amperage necessary to run modern headlights, therefore relays should be used. I am running a negative earth setup with a new harness on this 1965. Hella halogen headlights, bulb wattage unknown.



Any comments on this?

[triumphtr7guy]

Certainly cant hurt to go the relay route, an ounce of prevention!!! have done the same with the fogs on my TR7, very small plastic switch which is getting harder to source, yup, relay works well and keeps the switch from melting down.

[TeriAnn]

A whole lot depends upon what you do to your truck. The stock electrical system is pretty primitive and does not draw a lot of current. The stock switch without relays works OK as long as you don't have electrical accessories creep. Keep the power draw stock and the switch should remain happy.

You halogen lights will probably do fine if they have the same wattage requirements as the stock headlamps. It is when you start adding higher wattage headlamps, auxiliary lights, rear work light, radios, and other electric items that you draw more current than the switch was designed to handle.

I run higher than stock headlamps so I have a relay on the high beam and a relay on the low beam headlamp circuits. The LR horn can be pretty anemic sounding. I added a relay in the horn circuit and the horn is a lot louder.

I don't have electric accessory creep, I have an electric accessory flood. 400 watts of auxiliary forward lighting, radios, rear work light, rear fog lamp, heated seats, heated windscreens, Kodiak heater and more. So I added a relay to the power on-off circuit of my ignition switch. The only thing my on-off switch powers is the coil to my master relay which in turn provides power for all the switched electrics in my truck.

I have four or five dead ignition switches killed by too much power flowing through them. I hope to rebuild them some day but they remain a reminder of what happens when you draw more power than they were designed to carry..

[bobzinak]

I too upgraded my headlights to some hella lights. I purchased a heavy duty headlight relay from jcwhitney. one relay for high and low beams. just had to run a wire fron the battery to the relay, original wires from switch, and I chose to upgrade wire size to headlights.(optional). easy to wire in although you need to change the bullet connectors to spade connectors. also easy to put diode betwwn high and low beams so that both high and low beams are both on at the same time. much better than original wiring as the voltage is higher, you are not runing headlight voltage through all the rover wiring, (dc voltage does not travel well through long runs)
it's up to you how complicated you want to get, but a relay is recommended if you upgrade headlights. it was easy as the relay I put in really only requred 1 wire to be added. not two relays as some would install.. hope this helps... ROVE ON.. BOBZINAK

[TeriAnn]

easy to wire in although you need to change the bullet connectors to spade connectors.

I have discovered that a proper ratcheting crimp tool is close in price for the common American crimp on connectors and the UK bullet connectors. And crimping either is both quick and easy.

A big problem with DYI wiring modifications is that people use the cheap multi tools available at every hardware store that has a connector crimp function. The crimp is too narrow, it doesn't put a correct crimp on the wire nor the insulation. Much of the time the crimp is not tight enough to reliably hold the wire in place and it might slip out after while. Other people crimp it extra hard and weaken the connector.

I suggest that if you are going to play around with connectors that you spend the money to purchase a ratcheting connector that makes a proper crimp that is within the connector manufacturer's specification. The crimpers for both types of connectors are close in price. Your decision as to which style connector you use should be based upon which crimper you have. If you have a British car including a Series LR buying a UK barrel style crimper makes a lot of sense. Especially if you are trying to maintain a stock looking vehicle.

Of course what you decide to use is totally up to you. I'm just making a suggestion that there are other options than cutting off a UK barrel connector and replacing it with a US style crimp on connector. And that a proper crimp is more reliable.

Rovers North bullet crimping tool

Moss motors bullet connector kit (crimper, insertion tool, assorted connectors and barrels)

Tool for common American crimp on connectors

[jac04]

You can also solder the bullet ends on the wires - no tool necessary. I've done dozens of them by soldering. Juts hold the bullet end with the nose pointed down, that way any solder drip stays on the tip. After cooled off, a sharp file quickly removes the drip if necessary.

[Partsman]

I have discovered that a proper ratcheting crimp tool is close in price for the common American crimp on connectors and the UK bullet connectors. And crimping either is both quick and easy.

A big problem with DYI wiring modifications is that people use the cheap multi tools available at every hardware store that has a connector crimp function. The crimp is too narrow, it doesn't put a correct crimp on the wire nor the insulation. Much of the time the crimp is not tight enough to reliably hold the wire in place and it might slip out after while. Other people crimp it extra hard and weaken the connector.

I suggest that if you are going to play around with connectors that you spend the money to purchase a ratcheting connector that makes a proper crimp that is within the connector manufacturer's specification. The crimpers for both types of connectors are close in price. Your decision as to which style connector you use should be based upon which crimper you have. If you have a British car including a Series LR buying a UK barrel style crimper makes a lot of sense. Especially if you are trying to maintain a stock looking vehicle.

Of course what you decide to use is totally up to you. I'm just making a suggestion that there are other options than cutting off a UK barrel connector and replacing it with a US style crimp on connector. And that a proper crimp is more reliable.

Rovers North bullet crimping tool

Moss motors bullet connector kit (crimper, insertion tool, assorted connectors and barrels)

Tool for common American crimp on connectors

Don't balk at the prices of the proper tools, the proper tool will serve you for many years. I've owned one of the Moss moter ratcheting crimpers for over 20 years, and it's still going strong. Think of these as an investment rather than an expense and you'll be in the proper frame of mind.

[TeriAnn]

You can also solder the bullet ends on the wires - no tool necessary. I've done dozens of them by soldering. Juts hold the bullet end with the nose pointed down, that way any solder drip stays on the tip. After cooled off, a sharp file quickly removes the drip if necessary.

I've done that as well but it seems that the insulation tends to melt back leaving a section of bare wire hanging out of the barrel connector. When I solder a barrel connector I follow up with some heat shrink tubing to cover the bare wire.

As it turns out I have a proper ratcheting crimper for both the barrel and US style crimp connectors. Whenever I use one to make a crimp I have the satisfaction of knowing that the crimp not only looks right, the crimp is within the connector's factory specification and will be reliable.

If a job is worth doing it is worth doing right.

[johnny2rovers]

This should do it..........

[TeriAnn]

This should do it..........

Looks absolutely perfect to me.