j hook wiper 'upgrade', undoing rear wiper delete, rear defroster

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B

bshanna

Joined
Jan 6, 2018
Threads
7
Messages
70
Location
denver
Hi All,

In the MR2 world, the j hook wipers are considered an upgrade (theoretical better contact patch and blade options) - my 91 HZJ77 has the older style and the left side of my windshield pretty much never gets contact from the wiper. I was looking at just replacing the wipers but was wondering if anyone has 'upgraded' from the older to the j hook style. Theoretically they should be interchangeable but thought i'd ask.

Also, the PO did a rear wiper delete (there's literally just a knob on the rear door now). I find myself needing this driving up in weather quite often, can anyone tell me what i'm missing to add it back based on this pic? i can take a better one pretty easily.

DSC_2141.webp


Lastly my rear defroster doesn't seem to be working well or at all.. Any idea where to trouble shoot? The button on the dash appears to light up when switched and that's as far as it seems to work.

thanks
bret
 
switch on the rear wiper switch and see if the knob is moving. depending which setup the truck was, there should be liquid comming out of the nozzle. switches are of two types, one with just one speed and push for liquid and the newer ones with two stages wipe and liquid.

behind rear right hand side panel there should be the reservoir and pump. then, when you open the rear right door, you should be able to see the hose that goes to the nozzle, unless wrapped in tape (or missing)

for defroster, I think it should only operate when you have the headlights on.
First check is to see if you get power at the grid. I had none, removed the door panel only to find the wires disconected by the painter. Your car looks fresh paint, maybe that can be a cause.

if the defrost grid is interupted, then its posible to find some repair metal paste, but I had poor results with it.
 
ALEXY said:
switch on the rear wiper switch and see if the knob is moving. depending which setup the truck was, there should be liquid comming out of the nozzle. switches are of two types, one with just one speed and push for liquid and the newer ones with two stages wipe and liquid.

behind rear right hand side panel there should be the reservoir and pump. then, when you open the rear right door, you should be able to see the hose that goes to the nozzle, unless wrapped in tape (or missing)

for defroster, I think it should only operate when you have the headlights on.
First check is to see if you get power at the grid. I had none, removed the door panel only to find the wires disconected by the painter. Your car looks fresh paint, maybe that can be a cause.

if the defrost grid is interupted, then its posible to find some repair metal paste, but I had poor results with it.
Click to expand...

Thank you for there response - Pretty sure there is no liquid coming out the nozzle on the rear right now. I will have to check for the hose. I need to investigate why i don't get liquid out of the left front nozzle in the first place (probably unrelated).

The times i am expecting the defrost to work, i've definitely had the lights on driving at night. I'll take a look behind the door panel when i can get a chance. Oddly the first time i used it i felt like it worked but just barely okay. Then i tried again and it didn't seem to work at all.

thanks!
bret
 
Check the loom going into the rear doors mine were severed at some point causing some things to be inop.

The rear wiper arm for the 07+ J76 is perfectly compatible with the 77, and presumably with other hard top trucks with a rear wiper. On the plus side, the new design has the blade clip integrated. No more baby screws and clip out back.

1B1B693C-A58A-4F0D-BF22-787BCCFF2E56.webp
1B1B693C-A58A-4F0D-BF22-787BCCFF2E56.webp
 
@bshanna, your rear window tint looks pretty new. This is just a guess, but if you or another shop removed old tint with a razor blade, it may have messed up the integrity of the elements on the rear defrost. I'm not saying that is the cause, but it could be.
 
divemedic said:
Check the loom going into the rear doors mine were severed at some point causing some things to be inop.

The rear wiper arm for the 07+ J76 is perfectly compatible with the 77, and presumably with other hard top trucks with a rear wiper. On the plus side, the new design has the blade clip integrated. No more baby screws and clip out back.

View attachment 1840021
Click to expand...

Thank you - i will definitely pull the panels and check. Does the arm come with everything needed to mount and replace that ball that's currently on it or is the that potentially a different part?

Dprio34 said:
@bshanna, your rear window tint looks pretty new. This is just a guess, but if you or another shop removed old tint with a razor blade, it may have messed up the integrity of the elements on the rear defrost. I'm not saying that is the cause, but it could be.
Click to expand...

I'll have to check and see if the elements are okay. I would hope whoever tinted it was smart enough not to use a razor but who knows...
 
Hello,

Regarding the defroster, chances are the glass wiring is broken somewhere.

It does not need the lights on to work.

Measure the voltage across the wires. Wrap some tin foil strip around your multimeter's tips to prevent further damage. The voltage across functioning wires is 5 V; 10 V or 0 V indicate damaged wires.





Juan
 
Ages ago, I cut off the ends and welded J-hooks on that were cannibalized from some other vehicle. I like Divemedic's solution better - are the front wipers on newer J7's similar?
 
Whistler74 said:
Ages ago, I cut off the ends and welded J-hooks on that were cannibalized from some other vehicle. I like Divemedic's solution better - are the front wipers on newer J7's similar?
Click to expand...

Yeah the jhoooks are about $120 which is a lot for wipers... I bet the price is about the same even with the newer models (that's what the jhook is - a newer 70 series wiper arm).
 
divemedic said:
Does that voltage hold true on 24v systems?
Click to expand...

Hello,

The values came from a 12 V manual. I guess they are a little higher for a 24 V system.

One more thing.

When measuring voltage, make sure the positive tip is on the thick portion of the defrosting wire. Then lace the negative tip in the middle of the thin wire and then check.

20181130_0186 Defroster 1.webp


If voltage is 10 V, then the wire is damaged between the multimeter tips. If the voltage is zero, then the damage is outside the tips.

Measuring voltage without wrapping the tips can cause further damage. Ask me how I know.






Juan
 
Hello,

Now about pinpointing the damage.

With the positive tip in the thick section, slide the negative tip away from the positive. Check the voltage. The point where voltage changes is where the damage is.

20181130_0195 Defroster 3.webp


Before attempting repair, clean the damaged section thoroughly with a degreaser. Think of it as peeling the wire ends to make a twisted pair connection.

Mask the wire with tape. Repair the damage with conductive paint, and allow to dry.

Hope this helps.
 
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