Auto Electronics 101

[r-coupe]

I have and A1800 Mark 2 ute and I am currently installing a variable
(intermittent) wiper switch.

I am installing the variable control near the wiper switch and I need
to connect a wire to an 'ignition live' connection.

I would appreciate advice on the best position for an 'ignition live'
connection.

Thanks, Peter

[Eriks]

Hi Peter,

If I understand your query, you're looking for a circuit that only goes
live when the ignition is turned on?

I should probably have looked at the wiring diagram before I answer this
but, you could probably take the connection from the supply lead to your
existing wiper switch. The other circuit that comes to mind as being
easy to get at is the heater fan switch.

If your looking for a circuit that's always live, the cigarette lighter
might be the go.

Cheers,
Eriks

[Poida]

Hi Peter

I am going through the same thing with my Mk2, and had a brainwave....

Just put the variable circuitry into the "ON" feed to the wipers -
Turning on the wipers powers the circuit. This way you will not need
to change the switch or run extra wires. Turn the wipers on, turn the
variable resistor right forward for always on, or turn it back to
bring in the intermittent part of the circuit. I am either going to
install the "Volume" control where the dash ligh on/off switch is and
have the dash lights continually on with the head lights (have you
ever turned the dash lights off???) or hide it under the dash where it
does not take from the original look of things.

This effectively takes care of the need for another ignition live feed
to the park mechanism, as it will utelise the one that is already
there for the switch anyway.

Now I'll have a lie-down. All that thinking made my brain hurt!

Cheers

Poida

[r-coupe]

Hello Poida,

I am installing a Bosch intermittent wiper control - a rheostat type I
bought on Ebay.

The Bosch instructions state that it is best to operate the unit with
the wiper switch in the OFF position and 'power' the intermittent
wiper control from another ignition controlled supply.

Not sure what will happen if I connect it to the ON wiper feed, I will
need to think more on this possibility.

Notwithstanding, do you have any thoughts on other ignition controlled
supply points on the A1800 that are easily found - I would like to
install another fuse block for other accessories.

Thanks, Peter

[Eriks]

Peter,

From what you've just described it sounds like to need to run the intermittent control unit in parallel with the existing switch rather than in line with it. The easiest way as I tried to explain in my earlier email is to simply make your connections to the back of the existing wiper switch. You don't want to disconnect any of  the existing wires just piggy back off them. One of those wires will be a live ignition wire going into the switch, the rest will just be wires going out from the switch over to the wiper motor.

Some of the Lucas wiper motors have strange internal wiring and I know from trying to wire one up in an MG Midget that it's not always obvious, but typically you'll find the motors have a slow speed wire, fast speed wire (if it's a 2 speed), auto park wire, and ground.

Cheers,
Eriks

[Poida]

Hi Peter

I found a curcuit diagram that lends itself to being spliced into the
main wiper feed. It is relatively simple to make and does it's
switching by relay. If it works in mine as it is supposed to, I'll
pass it on. Failing that I would just run a lead back to the ignition
switch, onto the switched side so that it is properly off when the
ignition is off.

I'll have a look at the wiring diagram to find which you need to
attach to if you like.

Cheers

Poida

[r-coupe]

Thanks Eriks,

I have since looked at the wiring diagram and will probably go to the
heater fan switch or indicator supply, both of which become 'live'
when the ignition is on.

Is there a spare supply at the back of the ignition switch that I
could use?

I can't use the wiper switch as a 'live' supply as the variable wiper
I am installing is operated with the wiper switch turned off and the
Bosch instruction suggests using another supply.
- Show quoted text -
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Regards, Peter.

[r-coupe]

A good website to visit is http://mgaguru.com/mgtech/electric/wipe.htm

Some interesting information on electrics.

Peter

[tijgetje]

Peter,

Some years ago, I think late 80s, I also fitted a Bosch variable wiper
switch on my austin 2200.
Than I got the thought that the car should got back to its original
state, so i dismanteled all the extra features fitted.
As I remember I had the switch directly mounted between the fast speed
from the wiper switch and a live feed from the ignition swicht(colom
mounted).
Nowadays I would take a direct lead from the Battery(fused) for the
live feed.
I am planning to reinstall the switch(and other extras back) but have
lost the diagram, could you copy yours for me and send it to me by
email?
If you could tell me what are the different colors for that would be
ok for me.
I would be very pleased.

Maarten Kempen.

[r-coupe]

Hello Maarten,

If you send me your email I will see if I can scan and email the
wiring diagram.

Peter