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problems with wiper motor- BJ-7

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robert_ellison

Jedi Trainee
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I replaced the brushes and grease in my wiper motor and then reinstalled it but cannot get it to work, and keep blowing fuses. I checked continuity in the motor and it is present and have tried running leads from other power terminals to it but the fuses continue to blow.

I understand that the green line is hot but what purpose does the other wire (not the black one) serve. Must all 3 be connected in order for it to function?
 
Hi Robert,
Yes, the three wires are needed to make it work. My guess is you have put the green wire on the wrong terminal and you are going straight to ground with it. The "other wire" should be a black/green wire that goes to the switch on your dash. This is actually a ground wire that bypasses the park function. So the wiper motor has 1 hot and 2 grounds going to it.
 
My motor failed stalled and the high amperage blew the main fuse and all the tailights. Make sure your motor runs free. I can't speak for a BJ7, but my BN7 has the hot green wire going to terminal 2. The black wire goes to terminal E, and the black with green goes to terminal 1. The motor must be isolated from the metal platform it is attached to by using rubber mounts. The reason for the 2 ground wires is to enable the auto-park feature -- the motor keeps running until it parks itself. This is adjusted with the cap on the top of the wiper gearbox. The wiper switch completes the ground to activate the wipers. I made up a temporary wiring harness and ran the motor on a bench (using a spare battery) to make sure it worked before installing it. To sum up, you could have a jammed motor/gearing or incorrect wiring/ground fault.

.
 
when I added grease I packed the gearbox full of grease. Might that be a reason it may be jammed?

Yes, I will check the wiring but I don't think it is that as I tried hooking up either motor wire to green with the same result,however I'll go through the entire procedure again to verify that I wasn't asleep at the switch. At least I stocked up on 20A slow blow fuses to proceed.
 
Robert,

Check the wire that comes out of the motor case to the park function. Mine had worn a very small hole in the insulation and it was shorting out against the case and causing the fuse to blow.

Good luck,

Duane
58 BN6
 
Robert

you have asked all this, again on a different post, you already have the answers, try using the search, and the same people have given you the same answers!

andybj8 said:
Robert

Just put the battery on my bj8 to test all the electics and had the same problem, I had previously cleaned, greased and rebuilt it. Had to take the glovebox out to get at it again which was a pain. Regardless off negative or positive cars, on the bench, attach the + of a battery to the terminal 2 (was green wire) then attach the earth E and terminal 1 (was black / green) together and to the - of the battery to see if it works.

Terminal 1 is the internally limit switched contact for the park control from the plate in the gearbox.

My problem was that on reassembly the commutator was to tight against the case on the opposite side to the field windings.

To check the motor undo the 2 long screws on the top (terminal end) and prise off the top, check to see the commutator spins freely, checks the brushes, you may the need to remove the 2 screws in the body that lock the field windings to the body and pull off the body, you can then check the windings with a meter and visually. When you put it back together make sure it again spins freely (the motor body has a slight recess that only goes part way down inside, so make sure it is the right way up).

Dried grease in the gearbox may also be to blame, clean and regrease.

It doesnt take much pressure to stop the motor turning!

Hope that helps, cheers Andy
Click to expand...
 
Robert
I have just remembered that I have a similar problem on my boat-with eletric fan (Grece have very HOT sun)
one of the wires are very hot -motor must be aided to turn by fingers and rotate very slowly- I suppose
that consumption was more than 7-8 A and asumed that motor was demaged during a several grip (wrong bearing-project bug) and rotor probably partialy demaged and not recoverable

Note: AH Wiper motor abs. 2.2/max 2.9 A
Andrea
 
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