Back to intermittent wipers..

[R8rPhan]

Yep-includes shipping.

Cool.. Let me finish paying all my bills, so I can see where I'm at.. Probably buy in a couple days depending on how the CC thing works, otherwise in about a week.. If it's guaranteed working condition, consider it sold...

How come nobody makes these aftermarket/replacement?

Seems like it would be a good niche product..

Thanks,
Mark

 

[1976K20]

I have what you are looking for-you only need a working module (I refurbish the modules and benchtest) and a pulse delay switch-currently they are about $25-30 on rockauto or maybe $30-35 at a parts store. The module is the hard part to find. If you want a pulse/delay module I have (1) left for $75.

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Does anyone know if the module LMC sells works?

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[Rick Dobbins]

You need to replace the Park Relay. Green relay under the black plastic cover. Will fix it.

 

[R8rPhan]

So I bought a used Pulse Module from gmachinz (some sort of paypal snafu caused a 5 week delay in the transaction?).. But it got here finally about a week ago.. Yay!

Then I bought a new pulse switch for a 79 chevy C10 at Oreilly's earlier in the week, plugged the module in a little earlier, and the delay doesn't do anything.. If I move it to the left, it's spring loaded, and the wipers cycle once, and park..

If I move it one spot to the right, nothing happens.. I tried turning the speed knob to all the way both directions and a few places in between and waited.. nothing happens.. I'm assuming this is supposed to be the pulse delay position?

If I move it two clicks to the right, it cycles continuously at low speed and then parks when I move it back.. If I move it all the way to the right (3 clicks) it cycles fast, and then parks when I move it back..


Am I doing something wrong? Is there a potential issue with something else I should be considering (ie the wiper motor itself)?

Which is supposed increase delay time, turning the knob CW or CCW? and what kind of time interval should I be seeing between minimum and maximum?


I don't have a working windshield washer pump system, so pushing the button tells me nothing.. On the old switch, to use the washer, you just pushed the slider in, and it moved the thing to the left causing a momentary cycling, and it too was spring loaded moving it back to off when released.. When I push on this new switch, it doesn't force the lever to the left to cycle the wipers.. As if you're supposed to push it to spray the windshield and then move it to the left to cycle them, but I'm not really sure how it's supposed to work, as I don't have a pump hooked up...


Assuming the module and switch are good, what else should I be looking at to get this working?

Thanks.
Mark

 

[78C10BigTen]

So I bought a used Pulse Module from gmachinz (some sort of paypal snafu caused a 5 week delay in the transaction?).. But it got here finally about a week ago.. Yay!

Then I bought a new pulse switch for a 79 chevy C10 at Oreilly's earlier in the week, plugged the module in a little earlier, and the delay doesn't do anything.. If I move it to the left, it's spring loaded, and the wipers cycle once, and park..

If I move it one spot to the right, nothing happens.. I tried turning the speed knob to all the way both directions and a few places in between and waited.. nothing happens.. I'm assuming this is supposed to be the pulse delay position?

If I move it two clicks to the right, it cycles continuously at low speed and then parks when I move it back.. If I move it all the way to the right (3 clicks) it cycles fast, and then parks when I move it back..


Am I doing something wrong? Is there a potential issue with something else I should be considering (ie the wiper motor itself)?

Which is supposed increase delay time, turning the knob CW or CCW? and what kind of time interval should I be seeing between minimum and maximum?


I don't have a working windshield washer pump system, so pushing the button tells me nothing.. On the old switch, to use the washer, you just pushed the slider in, and it moved the thing to the left causing a momentary cycling, and it too was spring loaded moving it back to off when released.. When I push on this new switch, it doesn't force the lever to the left to cycle the wipers.. As if you're supposed to push it to spray the windshield and then move it to the left to cycle them, but I'm not really sure how it's supposed to work, as I don't have a pump hooked up...


Assuming the module and switch are good, what else should I be looking at to get this working?

Thanks.
Mark

My 78 intermittent if i push the knob in to wash i dont get any spray for whatever reason but it cycles the wipers 3 times then they park off. It doesnt slide the switch to the left either. If i manually slide the switch 1 click right it will go to delay depending how much ive got the knob turned BUT not always!! Idk if ive got an electrical issue, bad switch or bad modual.

 

[chengny]

FWIW, here is how the switch is supposed to work (from the 79 Service Manual):

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And the procedure for checking the switch:

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[R8rPhan]

FWIW, here is how the switch is supposed to work (from the 79 Service Manual):

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And the procedure for checking the switch:

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Dude!

Thanks so much for that... Sounds like I might have a relay issue.. The switch is brand new (but I'll ring it out), and the module is supposed to have been bench checked, so all that's left is the wiring and the relay... I rewired the truck, but for the wiper system, I just cut off the pig tails and spliced new wires to them, so the pigtails could have an issue (but I doubt it)...

This relay is located where? Must be in the washer motor or something because I don't see it in any of the wiring diagrams or did I come across it during the rewire..

Gonna print those docs out and put them in my folder with everything else...

Do you happen to have the pages for the relay test procedure as well?

Thanks,
Mark

 

[R8rPhan]

You need to replace the Park Relay. Green relay under the black plastic cover. Will fix it.

Where is this, on the wiper motor, or somewhere else?

 

[chengny]

Dude!

Thanks so much for that... Sounds like I might have a relay issue.. The switch is brand new (but I'll ring it out), and the module is supposed to have been bench checked, so all that's left is the wiring and the relay... I rewired the truck, but for the wiper system, I just cut off the pig tails and spliced new wires to them, so the pigtails could have an issue (but I doubt it)...

This relay is located where? Must be in the washer motor or something because I don't see it in any of the wiring diagrams or did I come across it during the rewire..

Gonna print those docs out and put them in my folder with everything else...

Do you happen to have the pages for the relay test procedure as well?

Thanks,
Mark

There is no relay in the 1979 wiper motor circuit. There is a "washer relay coil" in the washer pump circuit. Actually it would better be described as a solenoid - but regardless, it has no effect on wiper motor operation. I should not have posted that diagnostic procedure without deleting the reference to the "relay". That is a blanket diagnostic that covers a few different wiper motor systems. Yours is not applicable.

I read the entire post today and I noticed this:

my 73-79 Chevy C-10 (Wiring/cab appears to be '79)

Be aware that the wiper motor design, the control switch and the interconnected wiring for the 73 and 79 systems are all completely different. You can't mix and match any of the parts - well, the wires could be used if properly configured. I gathered some info on both systems. Take some time to look it over. It might shed some light on your issue.

Just one important difference is the way the motor windings are grounded. The 73 motor windings are grounded directly to the dash through the control switch. On the other hand, the ground path for the 79 motor windings is through the switch, to a splice point on a dedicated wire and then to the common grounding buss.

I have to split these images up - there are too many for one post.

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[chengny]

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1973 stuff:

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[R8rPhan]

When I rewired my truck (using a generic hot rod harness), I rewired the wiper/pump circuit 'direct'.. This is the way it is currently wired.. The penciled in writing is the color of the direct wires I used, the original colors are listed at each end of the wires...

Really hoping there's nothing wrong with this Wiper Module I just bought..

I'm gonna go out a little later, and bring the new wiper switch and module in, take pictures of them, and ring out the switch... Will take pictures of the motor too, and upload the pictures..

If I cant get this module working, all other options become a severely bigger hassle, cost.. from switching out to an expensive aftermarket system, to replacing the entire system with a later model system (I have a tilt column from an 88 suburban I was planning on putting in at some point down the road).. I'd probably go the latter route, as I'm getting tired of the constant oil and tranny leaks, and might just go ahead and change out both to a bigger engine and the 700R4 I have in the garage.. Got the column for that purpose (700R4)..

But I can't do any of that until I get another vehicle running (have a suzuki side kick that probably needs an engine), and a 2001 chevy express that is in Commiefornya smog hell (needs cat converters, and because of Ca Laws, will cost me 3 grand).

That stupid aftermarket intermittent wiper module that LMC and other places sell (where you have to constantly move the switch back and forth to change delay speeds) is not a very good solution, and is barely better than the current method of just leaning forward and holding onto the dang switch as I drive...

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[R8rPhan]

I think there might be a problem with this switch, in that when the 3 pin connector is pushed onto the back of it, the outside copper contacts are 'loose' and get pushed back into the switch, preventing a connection... I can easily push them down into the switch to about the place where the connector bottoms out, and then easily pull them back up to the end of the plastic piece they are contained in.. Like barely any resistance to push/pull at all... I don't think they're making connection, but rather just pushing the contacts back into the switch..

I also see a discrepancy in ringing out the switch in that the light blue is grounded only when the switch is set to 'hi' and the black with white stripe is grounded only when the switch is set to 'low'.. Only the dark blue is grounded when the washer is pressed in off position......

This lends me to believe that the green and two blacks are common, the dark blue is the washer pump, the black with white strip is the low speed circuit, and the light blue is the hi speed circuit..

Are the hi speed (light blue) and low speed (black w/white strip) really supposed to be connected at once when the switch is set to 'low?'.. Is the washer pump (dark blue), hi speed (light blue), and lo speed (black w/white stripe) really supposed to be all connected when the washer is pressed in with the switch set to the 'off' position? That just doesn't seem right.. Is the table wrong here? Why would the hi and low ever be connected at the same time? and why would either be connected when the switch is set to 'off?' why would the lo speed (black w/white) be connected when the switch is set to off?

Or is it really supposed to be like the table shows, and this switch is bad?

FTR, when the switch and module are installed, the low speed and high speed work as expected, as does the momentary (moving the switch to the left from the off position) for as long as it is held... Only the delay doesn't work (probably those loose connector contacts), so I suspect the table is wrong and not the switch..

Thanks,
Mark

 

[chengny]

I think there might be a problem with this switch, in that when the 3 pin connector is pushed onto the back of it, the outside copper contacts are 'loose' and get pushed back into the switch, preventing a connection... I can easily push them down into the switch to about the place where the connector bottoms out, and then easily pull them back up to the end of the plastic piece they are contained in.. Like barely any resistance to push/pull at all... I don't think they're making connection, but rather just pushing the contacts back into the switch..

I would fix this first. The fact that it may not be making proper connections will confuse the entire diagnostic procedure.
Thanks,
Mark

 

[R8rPhan]

I called the parts store and they are ordering a replacement switch.. They said that in the meantime, I could try to fix this one and they'd still take it back.. So I pulled the contacts back up and drilled through the plastic and the contact and pinned them in place with a little piece of toothpick..

Rung everything out, and still good.. Tried it in the truck, doesn't work.. everything but the variable speed works (pulse).. Took the module apart and measured resistance at the circuit board with the switch connected.. Can definitely see that the switch is connected and the resistance changes as the knob is turned..

So I guess I have a few options now... Repair the module (checked and a cross referenced Quad 2 input NOR chip is still available from Texas Instruments), or make a new one by copying this one. I might do both.. or I can make a new design based on this circuit, or I can design my own entirely new circuit, now that I understand how it works from the trucks POV... If I did that, I'd probably try to design something that is an all in one unit, (switch + pulse module), with the standard harness plugging into the back of that Like it does into the back of the module..

All the components are still available as far as I can tell (there's a couple transistors on the board I haven't checked yet) and I can cut a circuit board on the CNC mill (If I want to make some for sale or whatever, I can just design them on the computer and have a PC company print them for me).. It's actually a very simple circuit.. Very few components...

So, this little road to discovery caused me to ask the obvious question;

WHY HASN'T ANYONE DESIGNED AND MANUFACTURED A REPLACEMENT YET?

What am I missing? If these are as hard to get as they say, and there are as many people looking for them as there are, why hasn't anyone done this?

The only thing I'm having trouble finding (but I only looked for about 10 minutes or so) are the connectors/pigtails.. I think I found the empty 3 pin connector, and I found the 6 pin DELPHI-PACKARD part on a website but they are out of stock.. (Would have to contact them to see if this is a permanent condition or what)...

The two 'other' options I have is to install that tilt steering column from the 88 suburban I have, replace the motor/pump to match (haven't looked into how much hassle that is yet), get a module for that (readily available from what I can see) and adjust the wiring as needed (the option I plan to 'eventually do, but when I change the tranny to the 700R4 I have in the garage, but it's the most 'work' by far).. or to buy an expensive bolt in aftermarket wiper that has intermittent capability built in.. (Probably the easiest option but by far the most expensive)

Thoughts???

Thanks,
Mark

 

[Andreas Wickman]

I have a C20 1983 and did spend a lot of time to get the intermittent wiper system to work as original again. Work included restoration of the "delay" box by exchanging electronic components such as capacitors and others. In the end, everything works perfect and the only thing I will say with this message is that it was more than worth all efforts. If its something that really improves the driving experience is to have the FIVE wipings/washing modes the delay module gives.
1. Spring-loaded pulse by putting knob far left, just one cycle
2. One single push on the knob and I get 10 wash squirts with seven or eight wiper cycles. Perfect a winter day when you meet the school bus or a truck
3. Chooseable delay mode. One wipe cycle every 5- 20 sec.
4. Lo constant speed
5. Hi constant speed

So don't give up, but be sure you work with the right components and wiring for the specific truck. I definitely prefer to hold on to the original color codes of wires and connectors and to 100 % follow the original diagramme.

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