strange window motor issue and battery drain. 1990

Since I bought this car it has had a power drain and the passenger window motor works of and on.

I bought new motors and today while testing I found something strange. When new motor is not touching the regulator it works fine with the switch. However when you touch the motor to the regulator or ground it anywhere else on the car it runs on it's own without touching the switch. Also when you ground it it sparks really bad.

when the ignition is turned off it does not run on it's own when it is grounded. The drivers side motor works fine though and driver side switch works passenger motor fine as well. The problems start whenever the motor is touching a ground.

Is this a sure sign some ignition fed wire is grounding somewhere? Or is this normal? Everything appears to work normally on the car, it did have a aftermarket alarm system but nothing looked butchered anywhere and I taped anything I cut removing it.

I tried grounding the motor to the firewall as well and if the key was on the grounding point sparked and the motor ran on it's own as well.

anyone have a clue what I am dealing with here?

Another interesting thing to add to this is, the hatch release on the passenger door seems to always have power to both of it's wires which I think strange since I would assume the switch mearly grounds the hatch release motor.

There was an alarm in this car previously so I am not sure if something is remaining and causing these issues. But the problems are isolated to the passenger door only. I haven't checked the door ajar switch but I know interior lights don't come on when the passenger door is opened for some reason.

Well think I found the problem. Did all the FSM test procedures and it passed them no problem. So I tested everything the same way, took the new motor for the drivers door and plugged it in and it quiky arc'ed and popped the circuit breaker and stopped, it also started to turn once grounded without touching the window switch. Same symptoms as the original motor in the passenger door.

I then took the new motor for the passenger door and tested it the same. It didn't do this and worked perfectly when grounded against the regulator.

So I guess one of my new motors is junk .......... Now could this circuit breaker tripping and resetting all the time with the old window motor be the mysterious battery drain this car has always had. Basically it will drain the battery completely dead over night. The window switch doesn't need to be moved for the motor to arc and trip the circuit breaker.

I paid a 100 shipped for these dam motors and they were advertised as new not rebuilt.

JeffP1167 said:

Well think I found the problem. Did all the FSM test procedures and it passed them no problem. So I tested everything the same way, took the new motor for the drivers door and plugged it in and it quiky arc'ed and popped the circuit breaker and stopped, it also started to turn once grounded without touching the window switch. Same symptoms as the original motor in the passenger door.

I then took the new motor for the passenger door and tested it the same. It didn't do this and worked perfectly when grounded against the regulator.

So I guess one of my new motors is junk .......... Now could this circuit breaker tripping and resetting all the time with the old window motor be the mysterious battery drain this car has always had. Basically it will drain the battery completely dead over night. The window switch doesn't need to be moved for the motor to arc and trip the circuit breaker.

I paid a 100 shipped for these dam motors and they were advertised as new not rebuilt.

Click to expand...

Jeff, that that 'good motor' and jumper it in with clip leads/good connections on both sides to prove the point....they are electrically identical, so so prove the point....

do same with 'bad' motor....

something don't pass the sniff test on a couple reads through....

:thumbs:

Ok after putting this job off because the rivets got to me and replacing them and finding them a big hassle. I came up with as better idea, I left the transmission in place and took the new motor apart and put the electrical stuff onto the old transmission. I cycled the regulator about 30 times and it has worked flawlessly!

Here is the new transmission and old commutator and brush assembly and cap. I basically just put the new cap, commutator, brush assembly on old transmission after cleaning the inside of the old transmission and lubricating it.

easy job takes about 1/2 a motor.