Fluted rotary wiper knob - park facility

[KevinW]

I am planning on buying a set of the correct fluted wiper knobs for guys in the UK. The issue now is the switch.

I think the correct Lucas part no. is: PRS-7 54033632 or part no. 39156.

Heres 1 i found on ebay (now sold):
http://cgi.ebay.it/lucas-54033632-39...2#ht_500wt_949

The issue Im worrying about is how to implement a park function for the wipers as I think this is an Off-On-On, and I think I need a swicth with On-On-On.

Any good solutions, or is the answer 'originals didnt have a park function on the wipers'?

Kevin

[strictlypersonl]

The original rotary switch had the parking circuitry built in, but the NOS disappeared a long time ago. We use a Lucas 54033632 with a special relay board. Without the board, no parking function.

[Woodz428]

Originally Posted by strictlypersonl

The original rotary switch had the parking circuitry built in, but the NOS disappeared a long time ago. We use a Lucas 54033632 with a special relay board. Without the board, no parking function.

It's been a few decades since I owned some Lucas electrics, but I find that interesting. Most american wiper motors, at least those I've worked on, have the park built in to the motor. When you shut it off it cycles back to where the current ends...so to speak.
I'll have to check how the Coupe wiper system works.

[mickmate]

I believe there is a brush contact in the original motors. When you switch it off it keeps the motor energised till the park position is reached and breaks it there.

[strictlypersonl]

Originally Posted by mickmate

I believe there is a brush contact in the original motors. When you switch it off it keeps the motor energised till the park position is reached and breaks it there.

Not quite. A circuit is temporarily created that's supposed to turn the motor into a generator (through a grounded circuit) to quickly stop motor rotation.

[KevinW]

Thanks for the replies so far.
The two issues I was trying to raise (probably expressed badly) is

- whether you need an On-On-On switch, or On-On-Off,

and

- whether the switch I linked to would do the job ie park the wipers fully horizontal automatically when wiper swicth turned to 'off' position.

I think, but Im not sure, that the answer to the second question is No without a relay board, with jury still undecided on the first question?

.... so i guess I have to ask .... where do I buy, or how can I wire up a suitable relay circuit (I can implement sraightforward electrics/electronics)?

Kevin

[FatBoy]

Originally Posted by mickmate

I believe there is a brush contact in the original motors. When you switch it off it keeps the motor energised till the park position is reached and breaks it there.

That is correct. There is no circuitry required on the switch. All it needs is a swith that will provide an On-On-On facility. The first On position is really the Off position, but it provides an alternative live feed to the wiper moter, which is broken automatically at the motor by a cam when it reaches a pre-defined position.

My Kirkham was supplied without a park facility on the wipers and I've since rewired to to self-park. There was no additional circuitry required for the switch.

Paul

[westcott cobra]

A Rover P6 Wiper switch has the same turn-on design as the original Cobra switch, two speed function, a push function for washers and in some cases a intermittent position. I bought some via ebaymotors.co.uk.

They are availlable from time to time...

For the fluted knobs i bought blank knobs from the UK and gave them away for engraving. See here:
http://www.clubcobra.com/forums/atta...5&d=1235125750

Westcott

[Gonch]

Originally Posted by westcott cobra

A Rover P6 Wiper switch has the same turn-on design as the original Cobra switch, two speed function, a push function for washers and in some cases a intermittent position. I bought some via ebaymotors.co.uk.

They are availlable from time to time...

For the fluted knobs i bought blank knobs from the UK and gave them away for engraving. See here:
http://www.clubcobra.com/forums/atta...5&d=1235125750

Westcott

Hi Westcott,
Ive got myself a P6 wiper switch and wondered if you could help with the wiring. Ive put a multimeter across the terminals and come up with the following...

switching in a clockwise direction
POSITION FUNCTION TERMINALS
1 Intermittent ??? 3 + 5
2 OFF 4 + 5 + 6
3 SLOW 1 + 3 + 4
4 FAST 2 + 3

Would this work like this???
TERMINAL FUNCTION
1 SLOW
2 FAST
3 LIVE
4 EARTH
5 DELAY
6 PARK

I doubt my terminal interpretation is correct as I've sen other switches that have some pins always connected. Any clue you could give would be much appreciated.

Cheers

Fraz

[westcott cobra]

Long time no answer,

i'm in the middle of part collecting for my FE rebuilt, sorry...

The wiper motor i used is the same as shown on this page from Anthony Staffords shop:
http://www.s-v-c.co.uk/prod_wipers.html

Scroll down the page and find some helpfull infos and layouts

For the positions of the switch i will check it until monday next week.

Westcott

[strictlypersonl]

There are a bunch of threads covering the wiper circuit over on ffcobra.com. The toggle switch they use has a similar connection function as the rotary switch. Essentially off/on/on. Just to make things complicated, there are also a couple of different styles of wiper motor.

[mickmate]

Hey Kevin is that switch on,on,on do you know? If so that will work.

[mjhcobra]

I am in the midst of installing my wiper assembly and searching for the correct switches also. I am using the Lucas 14w motor found on Triumphs, MG's, and Mini's. On the 14w, the park switch is mounted on the motor. I currently am using a Lucas toggle switch 35927 and the motor parks each time the switch is shut off, but I need to know which rotary switch will perform the same as the 35927 toggle.

Any input will help. Martin

[westcott cobra]

Martin,

i will have a look on part numbers this evening and communicate them here.

Westcott

[Gonch]

I dont suppose anybody has found during there research a fluted knob with the 'PRESS FOR WASHER' engraved into it, like the attached pic?

[westcott cobra]

The switches i use have the following part numbers on the original boxes:

- 39 195
- 39 796

Both have a push washer function, not existing in the original switch, but i like the possibility to have a "hidden" washer funtion with the original look just in case....

The positions have the following internal functions:
OFF- curcuit closed for the park power
#1 - curcuit "OFF" cutted, circuit to #1 closed
#2 - circuit #2 closed
push- washer pump circuit closed

If you switch to park the 2 speed circuits are cutted and the OFF is closed again. The plastic park switch clipped to the Motor cuts the park circuit when a small bump on the motors big plastic gear lifts the contact tongue in the park switch in the defined park position.

Westcott

[FatBoy]

Hi Westcott,

Are they Lucas part numbers?

Thanks,
Paul

[mickmate]

The switch is indeed a Lucas PRS7 39156 in the originals. I think it will only work correctly with the DR3 motor though.

[Excaliber]

For what it's worth,,, the switch, whatever one, actually switches "ground". At least it's that way on mine. The "hot" side is always on and goes directly to the wiper motor, so your "making a connection" to "ground" when the switch closes any wire to the ground wire terminal on the switch. That means you may or may not be able to actually find any voltage present at the switch with your volt meter.

[mjhcobra]

Finally got one of the 54033632/39156 switches for my Lucas 14w wiper motor also. Now I need to confirm the wiring to the switch. Any help will be great.