Windshield wiper: 2 speed to intermittent

[mustardrocket]

My 78 has the 2 speed wiper and works fine. Just wondering if the LMC intermittent wiper switch would be a plug n play or if there is more involved than that to make it work.

[ray_mcavoy]

You'll also need the intermittent wiper delay control module.

Since you have a '78, the conversion should be fairly straightforward. The motor & wiring stay the same. You simply unplug the connector from the existing wiper switch and plug it into the control module. The module then plugs into the delay wiper switch.

See post #4 for a pic of the complete 78 - 83 wiper delay setup --> http://forum.73-87chevytrucks.com/sm...p?topic=9857.0

[mustardrocket]

Excellent. Thanks!

[buffydores]

I know I'm digging up an old one here, but felt it made since to tag along to this one. I tried doing the retrofit with my '78 using a '78 intermittent switch and a new intermittent control module. All I get is a one speed wiper control. Any ideas?

[cadillac_al]

I'm not positive but I think the wiper motor needs to be 79 and up. It's smaller looking than the older style.

[buffydores]

I think the cutoff is 78. 77 is the totally different setup.

[ray_mcavoy]

Yes, 77 was the last year for the larger round body motor. 78-up should have the slightly smaller permanent magnet motor that should work with the 78-up switches & modules.

As for only having one speed working after swapping in the intermittent switch & module, I'd recommend double checking the connections. It's possible that one of the contact terminals in the connector got bent slightly when it was unplugged and now isn't making good contact with the new switch/module. I believe the intermittent function makes use of the low speed circuit so a bad connection there would prevent both of those from working while allowing high to still operate normally.

[Peter S]

I took the intermittent switch setup out of my 79 and installed into my 78 without any issues. The 78 motor is the same as the 79.

[RADustin]

where the wipers the same from 78 to 91?

Is there anyway to retrofit a newer style blade to the arms? like the rain-x style that have no springs and are bent and give lots of pressure to the window?

I want to daily my square, but really the wipers is what is concerning me.

[ray_mcavoy]

Originally Posted by RADustin

where the wipers the same from 78 to 91?

The wiper motors are the same from 78 to 87 (and up to 91 in the R/V series). They did change from a mechanical washer pump (mounted on the motor) to an electric washer pump (mounted on the fluid reservoir) sometime around 85 but the wiper motor itself didn't change.

The wiper arms & linkage changed in 81 due to the re-styled front sheetmetal.

Originally Posted by RADustin

Is there anyway to retrofit a newer style blade to the arms? like the rain-x style that have no springs and are bent and give lots of pressure to the window?

Yes, you can install the newer "mono-beam" style wiper blades on the stock arms. There are numerous different attachment styles (bayonet, J-hook, side-pin, etc.) used to connect the wiper blades to the arms. Just look for blades that have mounts that will fit your truck's wiper arms. Not all brands/styles of blades will be available with all mounting styles though so you might have to shop around a little.

[RADustin]

great! Thanks for the info.

[gmachinz]

78-83 motors are all the same. 1984 went to stalk mounted wiper features and thus fender mounted washer pump inside the jug.

[Rich84]

My 84 has the control on the stalk with the mechanical pump above the motor...Which doesn't work by the way.

[RADustin]

how do I operate the manual pump on my '76 GMC?

noob question, I know.

[ray_mcavoy]

Originally Posted by RADustin

how do I operate the manual pump on my '76 GMC?

noob question, I know.

Just push the wiper switch knob in toward the dash. You can do it with the wipers already running or off. The switch is constructed so that it should automatically slide over into the "low" speed position if you push the knob for the washer while the switch is "off".

A momentary push of the button is all that is needed. If things are working correctly, that should engage the pump drive mechanism, the pump should deliver 3 or 4 squirts of the washer, and then automatically turn off (wiper motor will keep going until you switch it back off though). However, if the washer hasn't been used for quite a while it might take some time for it to pick up the fluid. And it might possibly need a new diaphragm if that's old & dried out (kits are available for them).

[70K10Hunter]

will a 78/79 wiper motor direct fit in a 77? I want intermittent wipers myself.

[gmachinz]

You need to open up the metal wiper switch opening a little to fit the 78-83 style delay switch-the bezel will still over it trimming. You might find the delay modules in a junkyard-I have a couple NOS modules but they are not cheap.

[gmachinz]

You also need to swap the wiper linkage arm from the 73-77 style to the 78-83 one...they are different enough that you must swap them. I offer conversion wiper harnesses to go from 73-77 standard to 78-83 delay between the switch/fuse panel and also underhood.

[70K10Hunter]

were 78-83 delays standard equipt? just making sure I am wrapping my head around this I need the wiper motor and the linkage from 80s and up to get delay?
gmachinz....I will still need the module correct? couple trucks local being parted out maybe I can score.

[gmachinz]

The 78-83 trucks had the 2-speed wiper switch as standard-the pulse/delay was optional. I'm out of goodnused ones so I have only NOS modules left for now. On used modules I update to newer style Panasonic capacitors in place of thebold ones on thebcircuit board and then test each one.

If you have a 73-77 truck and wish to use the 78-83 style pulse wiper switch you will need:

78-83 wiper motor
78-83 wiper motor linkage arm and nut
78-83 wiper switch and module
Underdash and underhood wire harness extensions.

For wiring you can follow the basic diagram for the 78-83 trucks and adapt this to your truck-keep in mind 1978 was the first year for the mini fuse panel vs older glass type so the wiring changed colors also from 77 to 78-this is why I offer a control harness which is correctly color coded for the 78-83 setup since that is the desired upgrade anyway. I keep it all factory appearing. Here is a complete kit I have on hand (several are in storage at the moment) to give you an idea of a typical "kit" I've offered up before. But if you want to source some salvage yards/Ebay and parts stores you can also prolly gather up everything you need.

[RADustin]

Originally Posted by ray_mcavoy

Just push the wiper switch knob in toward the dash. You can do it with the wipers already running or off. The switch is constructed so that it should automatically slide over into the "low" speed position if you push the knob for the washer while the switch is "off".

A momentary push of the button is all that is needed. If things are working correctly, that should engage the pump drive mechanism, the pump should deliver 3 or 4 squirts of the washer, and then automatically turn off (wiper motor will keep going until you switch it back off though). However, if the washer hasn't been used for quite a while it might take some time for it to pick up the fluid. And it might possibly need a new diaphragm if that's old & dried out (kits are available for them).

I'll keep playing with mine then. I was doing it correctly and the tank is full. But no action.

[RADustin]

Originally Posted by gmachinz

The 78-83 trucks had the 2-speed wiper switch as standard-the pulse/delay was optional. I'm out of goodnused ones so I have only NOS modules left for now. On used modules I update to newer style Panasonic capacitors in place of thebold ones on thebcircuit board and then test each one.

If you have a 73-77 truck and wish to use the 78-83 style pulse wiper switch you will need:

78-83 wiper motor
78-83 wiper motor linkage arm and nut
78-83 wiper switch and module
Underdash and underhood wire harness extensions.

For wiring you can follow the basic diagram for the 78-83 trucks and adapt this to your truck-keep in mind 1978 was the first year for the mini fuse panel vs older glass type so the wiring changed colors also from 77 to 78-this is why I offer a control harness which is correctly color coded for the 78-83 setup since that is the desired upgrade anyway. I keep it all factory appearing. Here is a complete kit I have on hand (several are in storage at the moment) to give you an idea of a typical "kit" I've offered up before. But if you want to source some salvage yards/Ebay and parts stores you can also prolly gather up everything you need.

how many detents are in the intermittent?

I wonder if it's possible to use a cadillac module or something similiar like detroit speed uses in their kits.

[truckin 79]

Since this is the place to ask about intermittent wipers, I have a question. I have 2 different modules and and 2 different switches. I tried both and neither worked that well. I just unplugged harness from old 2 speed switch and plugged in intermittent module in switch. So does the switch ground out through metal in gauge opening? I was kind of hoping they needed to be grounded and that is why the switches/module did not work. If it does not ground through opening then that means that switches/modules are bad right

[gmachinz]

There is a black wire from the switch which routes to the common ground location on the dash behind the LH AC vent. This ground provides the required negative signal for both switch and module BUT-with age there are several problem areas associated with the module being the capacitors and with the switch being the timer rheostat circuit. Bench testing will verify how well each works-and it can be a crapshoot.

[70K10Hunter]

gmachinz......looking at your kit I will still need linkage, so I will get that found and secured. pm me with pricing.

thanks for the info.