Mechanics

QUESTION REAR WIPER PROBLEMS

1999 Isuzu Rodeo

Electrical problem
1999 Isuzu Rodeo Question 6 cyl Four Wheel Drive Automatic 118k miles

Rear wiper ran continuously for a while - couldn't shut it off - finally blew a fuse. From then on every time ignition turns on the fuse blows. Long story made short - I have a new alarm/relay control unit and a new rear wiper motor assembly. Problem hasn't changed. If I unplug the wiper motor - fuse doesn't blow. I jumpered the wiper motor drive lines directly to the wiper motor without plugginng in the connector, leaving the internal " run" and " park" switches out of the circuit and the fuse doesn't blow. But the motor doesn't turn either. The " run" switch on the new motor (fresh out of the box) is closed, the " park" switch is open. Help!
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Pmollon
August 11, 2008.




Get another motor, it should have run when it was powered directly. Sometimes you can get a " new fresh out of the box" defective motor.

I took the new motor and hooked it up in a test jig through a 10 amp fuse directly to 12v. Fuse doesn't blow - it runs like a charm. Tried it with the old motor - same result. I noticed that when the washer turns on there is an audible click of a relay within the control unit. No click when I try the wiper. Possibly I fried the wiper relay in both the old and new controller? I have not been able to find a source for a schematic of that controller. Any ideas where I might find one?

Tiny
Pmollon
Aug 12, 2008.


http://www.2carpros.com/forum/automotive_pictures/30961_1izt_1.jpg



http://www.2carpros.com/forum/automotive_pictures/30961_1izb_1.jpg



I can email it if you like as you have donated.

Thanks for this. I have this drawing but it doesn't show what's inside the alarm and relay control unit. In any case here's my latest step: After I ran the motor directly from a 12v battery for a few seconds to check it out, I stopped it and checked the internal switches. Neither the " run" nor the " park" switch was made. I then hooked everything back up normally and tried again. The fuse did not blow but the motor did not run when I turned on the wiper switch. Is it possible there is a particular installation sequence that must be made before it works properly? Still baffled.

Tiny
Pmollon
Aug 13, 2008.
I didn't se anything special about the installation in regards to it running.

LEt's go back, I assume the fuse is good.

When you disconnect the wiper and washer switch, is the continuity of the switch normal?

If so, turn the ignition switch on, is there battery voltage between the rear wiper and washer switch harness side connector I-16 terminal 8 and ground?

If so, disconnect the connector of the rear wiper motor. Connect the motor side G-4 terminal 4 to the (+) battery terminal and the connector G-4 or the (-) terminal. Does the motor work?

IF so, check grpound C-36.

IF good, disconnect the connector of the rear wiper motor, turn on ignition, set wiper switch at wiper position. IS battery voltage present between connctor G-6 and the ground?

If so,
Disconnect the connector C-36. I the battery voltage present between connector g-36 and ground?
IF so, replace the alarm and relay control unit.

Thank you for this. I have gone through the procedure as you suggest. As long as the fuse is intact the washer has always worked fine. I took my test light and connected to the yellow/red lead at the input to the controller " wipe on input". I switched the wiper switch on and off 15 or twenty times and it functioned just fine, so the switch and the harness are fine. When I leave the ignition and wiper switch on and check at the motor connector, the lt green/black lead has the 12v from the fuse, but there's no sign of power across the motor input. (Brn/white to lt green/blue) Also, there's no audible click of a relay within the controller like there is when the washer is switched on. I have to conclude that the controller is bad. I'm guessing that the original bad motor fried the original controller and when I installed a new controller the bad motor fried it too. I now have a new motor and I'll have to either repair or get a new controller. I still would like to get a look at the schematic of the controller. Any idea at all where I might find it? Thanks for all your help.

Tiny
Pmollon
Aug 14, 2008.
I don't know where you'll find that. Some information is just not released by the manufacturer of the vehicle. Being a sub component, that isn't unusual.

The procedure I put on is not a guarentee. I crnge when I follow these type of procedures and it ends with, " then replace part X".
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