simple wiper question

[chengny]

The conductor that carries the pulsed signal is already included in either system. The color code is the same - just reversed:

1986 = (black/light blue) 1978 = (light blue/black)

For wiper/washer operation, you should not have to run any new wires - just splice the two systems together.

The only additional wire you might want to run is a feed for the wiper switch backlighting. It would run from your dash illumination circuit to the gray wire that leads into the pulse module.

 

[bucket]

The conductor that carries the pulsed signal is already included in either system. The color code is the same - just reversed:

1986 = (black/light blue) 1978 = (light blue/black)

For wiper/washer operation, you should not have to run any new wires - just splice the two systems together.

The only additional wire you might want to run is a feed for the wiper switch backlighting. It would run from your dash illumination circuit to the gray wire that leads into the pulse module.

But the truck in question is a '76 with different wiring for the switch and motor. The truck is one wire short of having enough for the '78-up conversion.

Wiring in a remote pump is easy, the two wires that plug into the wiper motor housing (for the washer pump) just get routed to the remote pump instead.

 

[chengny]

Ahh - so there are 3 sections from different years involved:

1. The components normally located in the engine compartment are from 1986 (washer bottle/pump & wiper motor) also included are the pigtails - that were cut at the firewall - attached to both.

2. The control components that would normally be located inside the cab are from a 1978 (i.e. the dash switch, the pulse module and interconnecting wire harness)

3. The wiring that passes through the firewall (and connects the control stuff in the cab to the operating components in the engine compartment) is still in place and original to the 1976 truck that is being modified to pulse wipers.


Did the 1976 truck originally have pulse wipers (and this is just an upgrade to a newer system) or did it come out with standard wipers (and this is a total modification from standard to pulse)?

Doesn't really matter, the good thing is that all 3 systems use the same number of wires to penetrate the firewall (4). The ground wires - on all three - drop out of the group and go to the common splice inside the cab.

The 1978 has 4 wires out of the module and through the FW:

Pink (washer), purple (low spd), gray (high spd), black/light blue (pulsed)

1986 has 4 wires thru the FW:

The colors and functions are the same except the pulsed signal is light blue/black

The 1976 (without pulse) has 4 wires that transit the FW:

Darkblue (washer ground), light blue/black (low speed), white/black (high spd), yellow/black (common hot wire to motor and washer solenoid)

So, if you disregard the colors of the wires that are currently in the truck and pass through the FW, it should easy to connect the 1986 engine side stuff to the components on the 1978 cab side.

 

[bucket]

I remember my '77 having only 4 wires pass through and the '78 module requiring 5 wires. Or at least, it was 4 vs 5 at the module plug. I'm going off memory here, but I'm pretty sure the '78 and later wiper motor requires a park switch wire and that was the reason for running another wire.

 

[chengny]

Yeah on a 1978 there are 6 wires connected to the module on the ... let's call it the service side (the side that connects to the engine compartment components). But two of them never make it to the firewall.

The ground wire (BLK 150) runs over to the common ground bus block by the parking brake.

The lead for the switch backlighting (GRAY 8) is spliced into the instrument panel illumination circuit under the dash.

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[datto62073]

So from what i gather i SHOULD be able to, if i am good about it, use some of my stock wiring (oe switch to motor) as basically my main harness. this is of course with jumping the proper leads to the washer, high, low, illumination and ground. now running a new wire for the pulse SHOULD be straight forward. i just wanted to make sure so i didn't have to run all new wiring.

i have the 78 switch and pulse box along with an 86 wiper motor with primary pivot linkage on motor and first piece of linkage to main wiper pivots and washer bottle.

i will be doing this swap as soon as i am done detailing and fixing what needs to be fixed on my MILs Explorer. i have ALOT to do on that.

THANKS GUYS!!!!!!

 

[datto62073]

Ahh - so there are 3 sections from different years involved:

1. The components normally located in the engine compartment are from 1986 (washer bottle/pump & wiper motor) also included are the pigtails - that were cut at the firewall - attached to both.

2. The control components that would normally be located inside the cab are from a 1978 (i.e. the dash switch, the pulse module and interconnecting wire harness)

3. The wiring that passes through the firewall (and connects the control stuff in the cab to the operating components in the engine compartment) is still in place and original to the 1976 truck that is being modified to pulse wipers.

yes thats whats going on.

Did the 1976 truck originally have pulse wipers (and this is just an upgrade to a newer system) or did it come out with standard wipers (and this is a total modification from standard to pulse)?

no, hence why i am asking what i am. i HATE non intermittent wipers. i would love to figure a way to put them in my Datsuns and my old Dodges as well.

Doesn't really matter, the good thing is that all 3 systems use the same number of wires to penetrate the firewall (4). The ground wires - on all three - drop out of the group and go to the common splice inside the cab.

The 1978 has 4 wires out of the module and through the FW:

Pink (washer), purple (low spd), gray (high spd), black/light blue (pulsed)

1986 has 4 wires thru the FW:

The colors and functions are the same except the pulsed signal is light blue/black

The 1976 (without pulse) has 4 wires that transit the FW:

Darkblue (washer ground), light blue/black (low speed), white/black (high spd), yellow/black (common hot wire to motor and washer solenoid)

So, if you disregard the colors of the wires that are currently in the truck and pass through the FW, it should easy to connect the 1986 engine side stuff to the components on the 1978 cab side.

this is good to know. and if i have to run a new wire, there are already several places i can run one. so i am not to worried since its an easy issue if i have to make a new hole.

 

[bucket]

no, hence why i am asking what i am. i HATE non intermittent wipers. i would love to figure a way to put them in my Datsuns and my old Dodges as well.

They used to male add-on wiper delay boxes, maybe someplace like JCWhitney still sells them.

I should be home this weekend, I should be able to take a look at my '77 and take some pics of exactly what I had to do. The extra wire isn't needed because the addition of pulse, it's needed because the '78 and later wiper motors are wired differently. You can add in the '77 control module and not mess with any wiring at all, but that module is basically impossible to find. My '77 still has it mounted under the dash somewhere, but it doesn't work (which is why I upgraded to begin with).

 

[89Suburban]

They used to male add-on wiper delay boxes, maybe someplace like JCWhitney still sells them.

I should be home this weekend, I should be able to take a look at my '77 and take some pics of exactly what I had to do. The extra wire isn't needed because the addition of pulse, it's needed because the '78 and later wiper motors are wired differently. You can add in the '77 control module and not mess with any wiring at all, but that module is basically impossible to find. My '77 still has it mounted under the dash somewhere, but it doesn't work (which is why I upgraded to begin with).

Yes I remember those! I bought one of them for one of my old Dodge trucks.

 

[bucket]

Yes I remember those! I bought one of them for one of my old Dodge trucks.

I have a couple of them that are still new, a neighbor gave them to me when I got my first car.

 

[datto62073]

IF all goes well this weekend, i should have sometime to work on this little project. but i'll be able to work on this anytime because as of tonight i am pulling the truck off the road for tires. the vibration is really bad and its pulling HARD right. oh well. it'll give me time to make sure the wiring is right and looks decent.

 

[bucket]

I kinda got screwed and can't be home this weekend, so no looking at the truck for me.

 

[89Suburban]

I kinda got screwed and can't be home this weekend, so no looking at the truck for me.