PV 6 volt blower switch

[arcturus]

Hi, do you think that the blower switch rheostat could cope with the wipers? Could be a way of having two speed wipers

[Derek UK]

I think the blower switch gets its 2 speeds by using a resistor for the slow speed and not via a rheostat. The wipers might not like to run at a reduced speed than standard. It would be like trying to run them on 3 volts in your case. The set-up is usually normal and fast.

[arcturus]

Just would like to slow them a bit in light rain. Also because of wear they have tendency to over run in the linkage and crash from time to time. With a bit less impetus the slower speed might mitigate that.

[Derek UK]

Maybe new plastic bushes in the linkage needed? Not an easy job, but if you could add a little extra bend to the arm where the short end section is close to the blade it would bring the inner end of the blade up a bit and away from the screen rubber. No, it's not the way the arm would like to bend but it will do it if you're careful. Blades would then park parallel to the screen rubber. I'm basing that comment on pictures of your car after the fire.

[arcturus]

Problem with working on wiper mechanism is that the whole dad has to be removed to access

[Ron Kwas]

Arcturus;

I agree with Derek, sloppy Wiper action is often caused by worn bushings...have a helper gently wiggle Wiper blades, and observe/feel for sloppy pivots/linkages in the mechanism (sorry, this will be under dashboard...so repairs will often be hampered by access and less than pleasant...the entire mechanism may need to be removed for best access for repairs...)

Cross-posted from FB in order to make it available in the future:

Please confirm your wiring corresponds that shown here:

...if so temporarily (for the purpose of tests) wire a 30cm length of steel coathanger wire in series with (Blue) supply wire from Fuse to Wip Sw, and turn ON Wiper Switch to power Wipers. If this gives the desired decrease in Wiperspeed (and wire doesn't get too hot to touch), make modifications permanent (coil coathanger wire and support it well and without shorting to anything else, and tuck it away under dash somewhere).
If more R/speed-adjustment is needed, adjust ch wire length. I do have a selection of low R/high power dropping resistors if you want to try your luck, and incur expense of having me send one. Contact me per e-mail directly about this.
I will also copy this info to VOC Forum to make it available again in the future by searching, and not disappear from FB forever (FB sucks!)

Additional: I just had an AHA Moment!...when I looked at Wiring Diagram again and realized that Blower Switch is a variable resistance (Rheostat Switch), and you're asking if this switch will be suitable as a speed decreaser for the Wiper...
Answer: Possibly (verify with practical tests)! The critical question which needs to be answered if Blower Sw is capable of handling the power(heat) it will generate when passing Wiper Motor current, and this can be determined by connecting it and testing, feeling for excessive heat generated...if when you wire it in series with supply wire from fuse, and turn Wiper Sw ON, and adjust this control for an acceptable Wipers-speed, after a few moments, feel switch to assure it is not getting very hot to the touch...if so, Blower Sw (RH) is not suitable, and I suggest you try the coathanger wire solution. (My general rule is: If you can touch it and keep your hand on it, it will last forever and is OK...if too hot to the touch that this is not possible, it is not a good long-term solution and must be improved...)

Reference info on Dropping Resistors: http://www.sw-em.com/Vintage_Volvo_6...ping_Resistors

Cheers!