Richard454

After driving the past two Hotrod Power Tours - 3000 miles in a week on my mostly original 73 coupe. There were a few things I felt were more a need that a want-

Working AC, overdrive trans and delay/intermittent wipers!!!


The wipers are really not that terribly tough to add a delay- but haven't really found one I like or thought it could be a lot better.

The two I have seen-

First the simple "555" timer board has been used- but since there's no way to "read' the location of the arms-they will stop at different positions each time. Sort of makes the modification half-baked - especially true if you add a wiper door in the mix. Cost- simple board found on the internet from $20 to a "packaged unit" for under a $100.





Second solution is using the late C3's intermittent wiper set-up. There have been a lot of issues w/ the 40 year old technology- pretty telling is that you can buy a harness to bypass the bad module!!! Not to mention the less than accurate delay cycles. Until recently, the replacement boards were unobtainable- now are new solid state boards- however you must find a used cover to control the intermittent wipers - new switch and place to put it- the wiper motor set-up - and if you have a pre-75 you'll have to add an outboard washer pump set-up plus wiring and connectors. So the cost- easily over $300 probably closer to $400.





Harness to BYPASS non-working intermittent wipers!!!




Here's my solution-

Late 90's GM wiper motor w/park- wiper switch controller and your old wiper motor. Getting these at your local Pull-A-Part about $35. On eBay less than $75-100.




I wired the "new" motor to it's controls-it worked great- NO external modules needed- all the electronics are in the wiper cover.

What it does-

- mist -turns on-sweeps once and parks
- wash -operates pump for a couple seconds wipers sweep twice and park
-5 delays (30 /15/8 /4 /2 /1sec) Sweeps once and doesn't park till turned off-
- low and high speeds.

Originally I was just going to use all the new stuff- replace the motor, switch and new wiring.

HOWEVER-

Could get the new motor to fit-even had same size stud for the arm. BUT the new motor was "clocked" differently- as the motor would have to be horizontal to park the blades correctly....bummer.


Line up the motors- and the park is in a different position- won't work!!!



Have to cut up the firewall for it to park correctly....





Plan B-

Use the old -dual field shunt speed controlled negative switched motor w/ the new electronics that were positively switched. Plus use the new cover on the old motor to so the electronics would "see" where the wiper arms were. That required swapping out the park solenoid switch as well to work w/ the new board.

I was able to make everything work-has to be a 73 or later motor case-because of the size of the park switch/solenoid- AND 68-72 w/ the wiper door controls can easily be added to the new electronics w/ a relay. I did have to use two Bosch (SPDT) relays to change the polarity and switch to high speed. But everything works as it should.

Hopefully will fit one in my 73 this weekend- next step is incorporate the stock push function to operate the washer and just add a rotary **** to control mist/delays/low and high speed. Thus everything will pretty much look stock but operate like what's found on newer cars.

BTW- I have a rain sensor board to try out on my 71. YES- you heard me correctly -uses an optical sensor...turns the wipers on when it senses rain!!!




New cover versus old pump cover- will have to add a washer pump pre-75



park solenoid through the years- 69-72 73 and the late 90's



Wiring- for testing- will use weather packs on the car. Power & ground- just run the harness and not use factory stuff. Blue and red wires operates washer pump.



The controls-just add ****



almost finished- some minor work needed to seal it up-



The "Rain Sense" board- note eight wires versus 6

toobroketoretire

I recently installed a "Revolution" and felt it did everything I wanted it to do once I got used to operating it. It's instructions said "Not For Use With Wiper Doors" but yet it worked perfectly on my '71.

74modified

Excellent work Richard. This was going to be one of my "get to it one of these days" projects. I thought there had to be a way to retrofit a newer motor. Thanks.

toobroketoretire

I'm still trying to figure out what he gained by all the work and expense when the $70 REVOLUTION provides 3 delay speeds; 8, 5, and 3 second while the wiper door remains open the whole time and the washer still functions as it did.

Richard454

Thank you!!!


You don't have to address me in the third person....

First of all- the expense? It only cost me about $25/ea- I have a 73 mostly stock and a modified 71 I'm going to do this conversion on.

Therefore, I'll save almost $100 (which I will promptly put in my retirement fund....) by not getting two pre-made delay boxes that really don't work correctly-the Manufacturer even claims that in the directions!!

Work? I sort of enjoy challenges...and do this as a hobby.

Actually- I'm sort of flattered that you don't see what I gained.

Richard AKA "He"

SwampeastMike

Be certain to provide updates regarding your attempt to add the RainSense wipers. Since you use that name am I correct that you're using a salvaged GM RainSense system.

Do be CERTAIN to use the special semi-liquid stuff when mounting the sensor to the windshield--you have to get it from a GM dealer. Also be aware that the wipers must FULLY wipe over the sensed area for the system to work properly! Such may prove more difficult than you imagine due to the design of your wipers that finds them both connected at the outboard side thus not wiping a "V" shaped spot in the top center of the windshield--exactly where the sensor is typically mounted above/behind the rear view mirror.

I have a GM with RainSense wipers. It works perfectly and the only thing that seems able to trick it is extremely heavy fog at night--I'm talking fog so heavy that it effectively coats the windshield quite quickly with an even layer of tiny water droplets. For whatever reason the system seems unable to "see" this at night and the windshield can become almost completely opaque without triggering a wipe.

On my car at least, the "RainSense" essentially replaces delay and you no longer have a timed delay setting. The system will however automatically operate the wipers constantly at both low and high speeds depending upon how hard the rain. The control module in mine is integral with the wiper motor cover but such is certainly nothing like in my '79 Corvette.

Also any GM new enough to have RainSense finds very few electrical accessories that are directly operated via the switches you use. In other words almost no switch in the car directly provides either power or ground to the accessory/motor/lamp/etc. Often control is done by providing a ground (that typically operates a relay) or a varying level (depending on switch position) of resistance (called a "resistance ladder") via a single wire. Such might cause problems when trying to add it to the primitive wiring system in a C3. Worse still is if any part of the RainSense uses the main data bus. The main data bus is a "one-wire" control system that allows any number of control modules located throughout the car to communicate with and provide instructions to other modules. This greatly reduces the quantity of wiring required. Unfortunately you can't just pick and choose modules you need for a project and expect to work in a different vehicle! First you have to have the PCM (power control module) that acts as a sort of "master" to all the rest of the modules. PCMs have evolved to the point that they have unique programming for every single vehicle. While these systems have great error detection/correction capabilities I would venture to say that it is effectively impossible to add such a system into a C3. Even if you managed to get it wired in and communicating properly it would likely sense so many errors that its operation would slow to a crawl or completely freeze up. Modules connected to the main data bus on a GM generally have two small gauge purple wires as the in/out wiring for the "one-wire" control system.

kanvasman

Thanks for adding ANOTHER thing to my TO DO list. I just can't keep up with that list. I admire the way you find a problem or issue and how you go about solving it. Kind of like throw your hat over the fence then figure out how to get your hat back. Nice work, again!

Richard454

Thanks Mike-

I'll post up the Rain Sense install on my 71-

And several people told me you can't put a BMW V12 in a C3 too!!!


This is late 90's stuff- so no can-bus. I found a good write-up on it here-

http://rivperformance.editboard.com/...ers-to-the-riv

and here-

http://www.cadillacforums.com/forums...8-deville.html

Sensor mounting kit- GM 25645365. Comes with solution, 2 pieces of mounting tape, an alignment plate and some cleaning cloths.

Rain Sensor module-



THANK YOU!!!



My problem is I keep picking fences w/ barbed wire!!!

76_vette_girl

Do your wipers park after each intermittent swipe?

76_vette_girl

Definitely doesn't seem to be an easy fix for those of us without the knowledge and wiring skills.. very impressive though...can't wait to see the finished results installed and looking/working fantastically.

Mooser

Nice job Richard (as usual) And very well written up.
Although not on my list I can certainly appreciate the work you put into these mods.
And I do know what we "gained" is not measured only by what is sitting there at the end.

M

hugie82

This looks like a good STICKY candidate!

Richard454

Thank You Sir-


Well- probably the reason it hasn't been done before- but I was able to noodle through it- no special tools or equipment needed- so it's not that tough!!!

And a special thanks to the internet and Willcox videos & tech papers !!!

Thanks!!!


OK- I messed with it some more- and was able to break out the washer function- just requires a Double pole single throw switch to activate.

So I'll have a rotary **** which will control -on/off/mist/delays/low/high and then a push button for the washer function.

Hopefully tomorrow evening I'll be able to make up the finished harness to go in the car- as I have it working as I envisioned it.

Here's a quick video- red light is indicated by the washer pump- does three swipes then parks-

alconk

Boy Richard, always thinking on how to make things better. You a Engineer for BASF by chance?

Richard454

HAHA -Nope. Thanks Al !!!

OK- got it mounted in my 73.

Works GREAT!!!

In delay- one sweep- doesn't park- doesn't stop midway- parks when you turn them off... Works like they should!!

Richard

Amorget

Richard - any reason you can think of that this can't be done on an 81? My module is dead and it seems that this would be a more reliable and cheaper solution than the $110 replacement module. As far as I can tell the 74-82 wiper motor is the same.

Richard454

I would actually be easier- as the 75 and later use an external washer pump. Plus how the OEM wiper switch is laid out- it be easy to accommodate the controls- just have a rotary **** and add a push button for the wash function.

Richard

Amorget

Any reason to think an early (84-89) C4 wiper switch wouldn't work? I am looking around for a wiring diagram but haven't found one yet.

Here is the one I am thinking: http://www.zip-corvette.com/84-96-c4...ff-switch.html

I might be able to mount it in the same place as the stock one

Richard454

It might- would lose some delay funtions-






97 Caddy- what I used for reference

Amorget

My wiring diagram skills are pretty weak, is the reason some of the pulse function would be lost because the resistance doesn't match between the two?

What about using the cover from an earlier vehicle, like from a Thirdgen: