Two speed wipers

[hsv-001]

When modifying old holdens in most states you have to put 2 speed wipers . When I built my first Vauxhall ,because it was "Caleche" [has a fold down windshield] the single speed wiper motor mounts through a hole in the windshield just above the steering wheel and the motor has a switch on it .The rules say I need wipers but originally it only had the one so with the help of a early MG bracket and some fittings I found in the shed I linked a second wiper to the first . The hard top coupe I'm now building will hopefully be a daily driver and the rules are the same as the holden with 2 speeds . I have fitted a morris mini single speed wiper motor and its plenty fast enough[ the splines are the same as early holdens so I can cut down holden wiper arms and blades etc.]




So now here is the question . While working on this Gallant I found a spare instrument light dimmer switch in the spare parts that were thrown in the boot . Tested it on a vintage dash mounted car fan and it varies the speed . So would it be legal to wire it to the single speed wiper motor making it variable speed ? Anyone have any ideas? Haydn   

[fcwrangler]

Haydn, you would be better asking the engineer what he thinks on it!. Two speed is just that slow and fast, if you are putting in a variable speed switch, it would have the same effect slower and faster speeds so I would say, while technically not a two speed set up it would be passable.
Jim

[mcl1959]

The engineering requirement is for 2 speeds that operate at certain ranges of sweeps per minute (I don't have the actual numbers to hand unfortunately)
Most single speed wipers operate at the lower range so varying the voltage will only achieve a slower speed not a faster speed. You need to check your wipers sweeps per minute and compare with requirements.

Ken

[Harv]

NCOP requirements:
"Two speed windscreen wipers with a fast speed of at least 45 cycles per minute (cpm) and a slow speed of at least 20 cpm must be fitted (single speed wipers are acceptable if the speed is 45 cpm or more)"

Cheers,
Harv

[mcl1959]

Thanks Harv, so in my terminology that would be 90 sweeps per minute and 40 sweeps per minute where 2 sweeps (back and forth) is equal to 1 cycle.
Is this the way you understand it?

Ken

[hsv-001]

Thanks guys , I will time the motor .Years ago when I converted the VW to 12 volts I forgot to install the resistor on the wiper circuit and the 6volt motor ran that fast that the rubber wiper blades were thrown off . So 6volt morris motor and a resistor is another option . Haydn

[Harv]

Yep, thats how I understand it Ken.

Wiper starts out half buried on the windscreen rubber, because the previous owner had put the wiper arm on one or two splines out  . It sweeps to the left, smearing all the dead bugs and road grime across your field of vision ('cause accessory washers to wash off the bugs are too expensive  ... and the diaphragms short-lived). Wiper hits the left hand side of the windscreen, making screeching noises where the perished rubbers are allowing the stainless arms to contact the glass (making the traditional 1/2-moons on the screen). Wiper then travels back across your field of vision and parks itself with a clunk back on the windscreen rubber, helping to strip out the already bodgy splines inside the wiper arm. This completes one cycle.

I've heard of guys working very hard to get their wipers to cycle faster than 45cpm just to avoid the two-speed requirements. New blades, polished screens, and even the odd coat of WD40 on the (wet) screen to get that last few cpm out of the old wiper motor.

I've still got the two-speed wiper setup that I bought off you nearly a decade ago - still a nice piece of work. The EK wagon is currently getting paint and panel, ready for rego (including with it's 2-speed wipers  ).

Cheers,
Harv.

[hsv-001]

No problems ,just timed it and I'm getting at least 45 full cycles per minute . So now I can put the variable speed switch in . Interesting what you say about the old wipers in your holden . Sounds exactly correct but I still wonder is this because the original cranking arms have been replaced with EK holden arms and the windshield wraps around on the EK therefore it can have a longer stroke on the cranking arms . Haydn

[DJ]

Haydn, I think only if the variable speed is =>45 cycles per minute at its slowest. Advice I had some time back was along the lines below - two speeds that meet the minimum number of cycles for each (20? & 45? cpm) - positive selection for slow & fast (e.g. switch/click in). Variable speed only complicated the discussion at the time & opened up too many 'what if' questions. I think that someone in a better mood may have been OK with variable speed for both fast & slow as long as it didnt decrease the speed to less than the minimum cycles for each setting.

[FCRB26]

I reckon the current draw on a dimmer switch would shag it pretty fast . im just using a headlight switch with a resistor on parkers..

[DJ]

I think it could too. Headlight switch sounds like a better choice and also provides a positive speed selection.
Maybe the parker position could be fitted with a variable resistor slowing it down to the minimum slow speed. But then it needs to turn or another control is added separately. A ready made switch with a third position for intermittent timing could be of more value driving & a lot simpler.

[hsv-001]

Ok, I have a 4 post resistor and a 3 position heater fan switch . So I'll wire the normal [fast] speed through the first position' the resistor on the second position and the rheostat on the third position .That should be fail safe . Haydn

[DJ]

Not pretending to be an engineer (just thinking out load) but it sounds OK to me as long as the 3rd selection doesn't allow the wipers to operate under the minimum 'slow' speed. I think the reason behind this minimum cycle speed is to ensure the arm doesn't remain in the line of vision too long & obstruct vision - hence, intermittent operation if the slowest speed is still too frequent for light rain on the screen.
Dave.

[hsv-001]

I find that in very light rain , turning wipers on and off is more distracting than the  wiper arm blocking vision . In the 1970's my mum had a variable intermittent wiper on a HG wagon and it was great when driving in very light rain. An old Saab that I drive also has a system where the wiper will wiper once about 6 seconds after you turn them off for a final windshield clean . Haydn

[DJ]

I agree & I think the addition of these variable timers were a great improvement. I think I'll go for that when I get to that stage. - fast/slow/variable timer.

[MalFE]

I found in my shed an unused electronic  intermittent wiper and washer control made by Mitsuba Electric MFG CO LTD in a box with fitting instructions.

Mal

[DJ]

I know two potential buyers if it's for sale.