MGB MGB wiper motor swich question

[restorejag]

I have a 1975 Mgb.I want to get rid of the column wiper switch and
use a toggle on the dash.I still want two speeds and park.
Any one know how to wire it.

 

[DrEntropy]

You can use a headlight switch from a pre-67, three position, but you have to use an ohm meter to suss the order of the connections... and a wiring diagram. I can't pull that outta me a.... err... pea brane at th' moment.

 

[Kimberly]

I don't know if a headlight switch will work.
Headlight switches generally work as such;
first position allows continuity between two contacts (tail lights) and the second position connects all three contacts (tail lights and headlights)

The type of switch you are going to need is an on-off-on, whereas one position will connect nothing (off), another position will connect the power input to one power output, and the third position will connect the power input to the other power output.
Input - green wire
For the output, you are going to have to determine which wire is which or someone else can tell you. There are three wires for the different speeds, intermittant, slow, and fast. The wire colors for output from the stock switch are blue/lightgreen, red/lightgreen, and brown/lightgreen.

Check with electronics stores to see if they have a style switch you would like. Examples would be toggle, rocker, turn knob, etc.

An example of a Lucas switch would be the one used for two-speed fans such as the one used in '78 models.

Using an on-off-on or the fan switch, you will lose the intermittant function. It maybe possible to find an momentary/off/on/on switch at an electronics store, whereas you would be able to keep the intermittant function.

 

[DrEntropy]

On the two position toggle used for the headlights on a pre-'67 MGB (P/N 31837E) the switch can be used for a two speed wiper thus:

Terminal #4- power in (green, usually).

Terminal #6- low speed winding connection (I don't recall color).

Terminal #8- high speed winding connection (ibid).

The "park" function is internal to the wiper motor.


Terminals 6 & 8 are isolated from eachother internally, connected with terminal #4 one at a time.


HTH

...This is ~IF~ you wanted to use a Lucas headlamp switch in th' first place... :wink:

<span style="font-style: italic">
<span style="font-weight: bold">EDIT: And WELCOME to th' Forum!!</span> </span>

 

[Kimberly]

On the two position toggle used for the headlights on a pre-'67 MGB (P/N 31837E) the switch can be used for a two speed wiper thus:

Terminal #4- power in (green, usually).

Terminal #6- low speed winding connection (I don't recall color).

Terminal #8- high speed winding connection (ibid).

The "park" function is internal to the wiper motor.


Terminals 6 & 8 are isolated from eachother internally, connected with terminal #4 one at a time.


HTH

...This is ~IF~ you wanted to use a Lucas headlamp switch in th' first place... :wink:

<span style="font-style: italic">
<span style="font-weight: bold">EDIT: And WELCOME to th' Forum!!</span> </span>

My understanding of how the headlight switch works.
position one - only connects terminals 4 to 7 (tail lights)
position two - connects terminals 4 to 7 (tail lights) <span style="text-decoration: underline">and</span> terminals 4 to 8 (headlights)

Using a pre '67 headlight switch, can you turn on the headlights without the tail lights if you were to use terminals 6 and 8 instead of terminals 7 and 8?

 

[DrEntropy]

That would be what I found this AM by ohming the switch. It bugged me all night, as I ~distinctly recall~ doing a similar switch arrangement to my first B.

Tho I don't think it advisable to run around sans taillights in the dark, unless... mmm...

ohnevermind.

 

[restorejag]

Thanks for all the help.I have tried two switches ,a pre 67
and a dp/dt both work,two speeds but will hot park.73-80
wiper switchs uses five wire output.U/LG,G,R/LG,N/LG,B. Black is jumped to the green. Wiper motor side,U/LG,G,R/LG,
N/LG, Black to ground.The stocked 75 switch works fine,two speeds and parks.I am puting
a pre67 dash in the car,which is the reason for the switch change.Any suggestions.

 

[Kimberly]

Stock wiper switch output is
red/lightgreen, brown/lightgreen, and blue/lightgreen. I don't know which wire goes to the following.
fast
slow
intermittant

The black and lightgreen/black wires go to the washer. The washer has a switched ground.

Green is input for the wipers. The wipers are switched power.

The green wire going to the wiper motor is for the park switch. Power for the park position doesn't go through the wiper switch.