How to: END ALL 98-01 REAR WIPER PROBLEMS!

[jcevans2]

O.K. quick update. I hadn't put the lift gate trim panel back on yet so I thought I would play around with the wiper circuit. I tried to figure out the little "twitch" in the wiper after the wiper switch is turned off. First thing I did was apply jcevans2's theory and ground the old park sense wire(vt/yel). That didn't stop the twitch, however it did happen quicker! There was no delay after turning off the wiper, it happened right away. I also tried using a relay on the park sense wire so that it was only grounded when the wiper was turned off. No difference there either. Another thing I noticed is that on the 98-01 wiper relay when the relay releases it goes to ground, but the 02-03 wiring does not. So I modified an old relay by removing the terminal that connects to ground. This had no effect either. So back to the drawing board on this issue. Need to put some more thought into this one and see if we can figure it out.

The reason why the 98-01 wiper relays go to ground is because the circuit is designed with two separate circuit actions. Electrical current flows through the wiper up relay, through the original 98-01 motor in one direction, and then through the wiper down relay to ground to complete the wiper up action. It could have been designed to go to ground in any one of several ways but routing it through the wiper down relay to get to ground, I assume, is probably the most efficient way to do it. This allows the same wires to be used when it switches over to the wiper down action. Now the electrical current can flow through the wiper down relay, through the original 98-01 motor in the opposite direction, and then through the wiper up relay to ground to complete the wiper down action.

The 02-03 relay does not need to go to ground on that side of the 02-03 motor because it has combined wiper up and down in to one circuit action. The motor has a diode in it so electrical current will only flow in one direction on the wire going into the diode when the relay is activated. When the relay is released, the current just stops flowing. This is why when you separated the relay terminal from ground it didn't have any effect on anything.

Good thinking though.

 

[albi1cnobi1]

The reason why the 98-01 wiper relays go to ground is because the circuit is designed with two separate circuit actions. Electrical current flows through the wiper up relay, through the original 98-01 motor in one direction, and then through the wiper down relay to ground to complete the wiper up action. It could have been designed to go to ground in any one of several ways but routing it through the wiper down relay to get to ground, I assume, is probably the most efficient way to do it. This allows the same wires to be used when it switches over to the wiper down action. Now the electrical current can flow through the wiper down relay, through the original 98-01 motor in the opposite direction, and then through the wiper up relay to ground to complete the wiper down action.

The 02-03 relay does not need to go to ground on that side of the 02-03 motor because it has combined wiper up and down in to one circuit action. The motor has a diode in it so electrical current will only flow in one direction on the wire going into the diode when the relay is activated. When the relay is released, the current just stops flowing. This is why when you separated the relay terminal from ground it didn't have any effect on anything.

Good thinking though.

That's why multiple brains are better than one. :scratch: I looked again at the schematic, and you're right. That's exactly what it does.

 

[CDW6212R]

A small side note, not related to the wiper itself. Since the washer nozzle on the 98-01 is on the wiper arm, when the 03 wiper is installed you lose the washer on the rear window. I'm in the process of adding back the rear washer nozzle on my truck. I'm going to put it in the same place as on the 03, above the window on the hatch. I'll post some pics as I make any progress.

Please do, I bought that nozzle too, but it's been so long I could use refreshing.

 

[SupaSwope]

@albi1cnobi1 Can you fix your links with photobucket? I would really like to see the pics.

 

[Mbrooks420]

It's not the links with photobucket, it's photobucket itself, I believe. Did you try Turdles link fix?
http://www.explorerforum.com/xenfor...ucket-hot-link-fix.465843/page-2#post-3648220

 

[CDW6212R]

For summary, here is the main information as Al posted it earlier on page 2, the text at least;

I'll try to break it down a little more for you. Simply put, the 98-01 wiper motor circuit uses 2 relays and 4 wires to run the motor. The 03 circuit uses 1 relay and 3 wires to run the motor. In order to adapt the earlier truck wiring to run the 03 wiper motor you have to eliminate the un-needed relay. To do this you need to remove the "wiper down" relay(relay location #8 in the battery dist. box) and put a jumper in between pins #3 and #5 . This basically fools the 03 wiper motor and the GEM module into thinking all is well. Since you only need 3 of the wires and they're different colors on the different year truck and glass you need to figure out where they go. You can start off with the violet/yellow wire that fed the old motor. That wire won't be used now. It used to be for the GEM to know when the wiper was turned off so it could "park" the wiper down off the glass. The new wiper doesn't park like that so that wire isn't needed. 2 of the other 3 wires have basically the same function on both years, they're just different colors. The black wire is the ground on both so just splice black to black. The white/orange wire from the truck harness gets spliced to the violet/yellow of the new motor and the black/light blue wire from the truck harness gets spliced to the brown/white wire of the new motor. Thats pretty much it in a long rambling nutshell. If you do this and have any questions post em up, I'm sure we can help you out.

 

[CDW6212R]

Here is the first post of his showing the wiring diagram pictures. Because PB has screwed everyone who hosted pictures there, we cannot copy those pictures any longer, to share them etc.

So for now, the link embedded in the posts will take you to the member page, and you can scroll through the pictures. Most of his pictures are there from this thread. That's slightly helpful, we can still look at the pictures for the time being.

I thought I would post these up to help anyone considering this mod.
98-01 wiring

03 wiring

 

[albi1cnobi1]

Here is the first post of his showing the wiring diagram pictures. Because PB has screwed everyone who hosted pictures there, we cannot copy those pictures any longer, to share them etc.

So for now, the link embedded in the posts will take you to the member page, and you can scroll through the pictures. Most of his pictures are there from this thread. That's slightly helpful, we can still look at the pictures for the time being.

Hey Don. It's been a while, hope all is well with you. I hadn't heard of the add on for chrome to fix the photobucket issue. I just added it and cleared my cache and it looks like I can see them again. I haven't been on here in a while, but I still lurk occasionally.

 

[CDW6212R]

Great to see you back too Al.

For this wiper project, I was looking for an entire hatch to get rid of the holes ours have. But after hunting for a long while, I concluded that it appears that all 02-03 hatches have the very large molding along the bottom. Those have tons of holes behind them to mount it. So that wouldn't be a good idea, and I've got my newest keeper truck, I'll fill those wiper holes the normal way.

I like that back-up camera there, slick. I don't plan one for my 98 Limited, but I'm going to use a license plate camera for my 99/mail truck. I need a decent DVD player that can use the steering wheel controls with it. Later,

 

[traveler]

Subscribing.

 

[Spudhut]

not to hijack the thread, but will this work on 97' sport?

Great thread, lots of details....Thanks!

 

[Mbrooks420]

97 sport should have the flat rear window. Your spring is likely just worn.

 

[albi1cnobi1]

not to hijack the thread, but will this work on 97' sport?

Great thread, lots of details....Thanks!

Well, the short answer is yes. Anything can be made to work. That being said, I only researched the 98-01 and 02-03 wiring. I'm not familiar with the 97 wiring. The best thing that I can suggest is to get a wiring diagram for the 97 rear wiper circuit and compare it to the 98-01 that I posted here. If they are the same it will work.

 

[Mbrooks420]

Will the rounded glass fit properly on a flat glass hatch?

 

[Mbrooks420]

I was able to fix my rear wiper on my 96 by pulling the spring and polishing it up on the inside. It was binding up. If you lift the wiper to a near 90 degree bend at the hinge there are two rounded stops it rests against under spring pressure. I removed some material from these with a file, and it worked considerably better.

 

[Spudhut]

Can anyone suggest where to get rear wiper blade, other than dealer? I have looked at the major chains, even bough a cheapie to pull the blade and swap into carrier...no luck! Thanks!

 

[Mbrooks420]

I found them at advance. Did you check Amazon or rock auto?

 

[Spudhut]

I found them at advance. Did you check Amazon or rock auto?

I was trying to find locally, but ill look at RockAuto. Thanks for the suggestions.

 

[Mbrooks420]

Are you looking for a 14? A quick search showed them in stock at Advance, Walmart, and O'Reiley.

 

[CDW6212R]

Yes, get the 14's, avoid the 15" wiper. The longer wiper is most likely to scrape the hatch or hang off the edge. I had trouble with the first 15" I tried, and then the 14" worked great as a replacement on my 99.