# 1994 B4000 Window Problem

#### Walksnotruns22

##### Member
U.S. Military - Veteran
My passenger window seems to be getting no power. The window button on driver and passenger side do nothing and doesn't even sound like it is trying to do anything. I tried hooking up a 9v battery to it but not sure if I was even doing that right because it was still the same thing happening.

Any ideas?

#### RonD

##### Official TRS AI
Power windows in any year and pretty much any vehicle all work the same way

Motor is DC and has 2 wires, which means motor will spin clockwise if it has 12v and ground, then if you reverse it to ground and 12v motor spins counter-clockwise, window up and window down

That's what the door switches do, control the polarity, +/-, on the two wires at each motor
BOTH motor wires are grounded(-) at each motor all the time by the switch for that motor
When you press the switch, ONE WIRE is ungrounded and then connected to 12v, motor now has 12v and ground(other wire) so it spins
Push switch the other way and Polarity is reversed and motor spins the other way
easy peasy, window up and window down

Master switch, this seems more complicated than it is
The drivers door switch is as described above

Passenger door switch on Drivers door has 2 wires that run to passenger door switch
These 2 wires are the GROUNDS for the passenger door switch
When you press the button on drivers door switch it does as described above, one wire is ungrounded and connected to 12v, so passenger door motor spins

For the passenger door switch to work on its own it needs its own 12v wire from same fuse as driver side gets it 12v
So passenger side switch has grounds from drivers side switch and is own 12v wire
So it can operate the same as described above

There is ONLY one ground wire in the whole system, for drivers door switch, it is behind the kick panel on that side
There is only 1 fuse, in 1994 its a Circuit Breaker, #14 30amp in cab fuse box

No, a 9v battery wouldn't spin the motor, no AMPs
You need a volt meter, set to DC Volts
Unplug the motor's 2 wire connector
Key ON
Hook up light or volt meter to the 2 wire connector that goes to the switch
Press the switch
Should see +12v OR -12v
Then press switch other way, and it should reverse + and -
If so and motor doesn't work then motor is bad

If no +/-12v then most likely the circuit breaker is bad, unplug it and test with OHM meter, should see 0 ohms by touching both terminals with the two meter probes, one probe on each terminal of the fuse/circuit breaker

All power window motors have a thermal limiter inside, this is what stops the motor turning when the window gets to the top or bottom of its track
When window stops moving motor heats up instantly and the thermal limiter OPENS, cutting power inside the motor, it quickly resets, but......................................not always, lol, and motor will no longer work, and not a serviceable part

Auto UP or Auto Down, this circuit was added in later years, its a separate module, 1994 doesn't have it

Just FYI
In a 4 door its the same setup, just 2 wires from driver's door master to each door/window, and one 12v wire to each door/window, so 6 wires out from master, and 4 wires from fuse/relay one to each door
1 ground wire, behind driver side kick panel

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#### Walksnotruns22

##### Member
U.S. Military - Veteran
Thank You.

Since it's only passenger side that doesn't work then the breaker should be good.

The driver side works fine.

Sounds like it could be a ground problem or motor problem.

#### RonD

##### Official TRS AI
Yes if one window works then fuse is OK

As per the wiring diagram, there is a 12v wire at the passenger side switch, light blue/black stripe wire, Key ON

The tan/blue and white/yellow wires are both Grounds, if Master button is plugged in and not being pressed
So you can use volt meter or test light to confirm 12v and two grounds at passenger switch

If all 3 wires test OK then motor is bad
It is possible switch is bad, just unlikely as its rarely used, compared to Master which is the one that gets the daily work out

Confirm by testing the two motor wires, should have +/- 12v when button is pressed

#### Walksnotruns22

##### Member
U.S. Military - Veteran
So just tested all the wires and they all light up the test light. The connector also have 12v so that must mean that I need to order an new window motor. YAY ME!!!.

#### RonD

##### Official TRS AI
Or get the whole regulator with motor from wrecking yard, has to be passenger side

You will need to drill out the rivets holding the regulator to the door and replace them with bolts and nuts, use lock washers
You need to do the regardless of just new motor or used motor/regulator

You can use a few pieces of masking tape on window, over top of door and down window on the other side to hold the window up for disassembly

#### Walksnotruns22

##### Member
U.S. Military - Veteran
Good call on that. I do have to take the other back window back still as well and find somewhere to get another one that fits properly. Looking like I am going to have to pull a back window out myself at a wrecking yard and since already doing that might as well get window motor.

Thanks for all the help.

#### Walksnotruns22

##### Member
U.S. Military - Veteran
So I am properly confused now with this passenger window. I have got a new motor and regulator and it works but I still have a problem. So there is power to driver window and the driver side button for driver window works but not passenger button. The passenger side window button doesn't work on the passenger side. I tried connecting new motor to the connector before tearing old one out and it doesn't now work.

Would a bad passenger side switch cause this problem?

If not what else should I look for?

The wire from the switch to the connector is only like 2 feet long and looks fine.

#### RonD

##### Official TRS AI
The drivers side Master uses its own 12v and Ground to activate the passenger side motor
The passenger side switch is by passed, i.e. the 2 wires from Master are connected directly to the motor on the back of passenger side switch

Master==============||======motor

Passenger side switch will have 5 wires
2 are IN from Master
2 are OUT to motor
One of each is connected to other in the switch

So one IN from Master is connected directly to 1 OUT for motor, when switch is plugged in

Then one 12v wire as the 5th wire

So yes if Passenger side switch is broken inside and not connecting Master to motor directly then neither master or passenger switch could activate the motor

Unplug passenger side switch
The light blue/black wire is the 12v in the enter of connector, avoid that one
Should see 2 wires at each end of connector
Jumper those 2 wires together
And jumper the other ends 2 wires together
You have done what the switch should do when its plugged in

Now, key on, try Master to see if motor activates, if so passenger switch is confirmed bad
If still no activation then one(or both) of the 2 wires from master to passenger side is bad, which causes both switches to not work

Last edited:

#### Walksnotruns22

##### Member
U.S. Military - Veteran
So I went back and looked at the wiring diagram and grabbed test light. The yellow red wire has constant power and the red yellow has power when hitting switch on passenger side.

#### Walksnotruns22

##### Member
U.S. Military - Veteran
Quick update. I tore down the driver door and found out that someone already replaced the switch. The connects on the driver side switches were loose and fell off. I was able to hold them on to test it only worked on the new motor.

Does that mean passenger side switch is bad?

I am already assuming with all this testing and stuff that the motor is bad no matter what.

#### RonD

##### Official TRS AI
Not familiar with Mazda color code

But same color wire at both door switches should have 12v with key on
The 2 wires from master should both be grounds 24/7 unless master switch is pressed

If master can control passenger window then motor is OK
If Passenger switch can not control motor AND 12volts is present at that switch with key on, then passenger switch is bad

#### Walksnotruns22

##### Member
U.S. Military - Veteran
Ok. The diagram you posted on a previous thread is the exact colors I have.

The driver side will control the new passenger motor (the new one I picked up from junkyard) but not the old one. The passenger side won't control the new one or the old one.

#### RonD

##### Official TRS AI
Replace passenger side switch, if the light blue/black wire has 12v with key on

#### Walksnotruns22

##### Member
U.S. Military - Veteran
Copy that.

I been trying to figure out how to take this switch out but can't find out how. The switch has the wires going into the switch. Also the part number on the back of switch I can't find anywhere and nothing comes up online.

None of the ones I find online have the same connections in the back.

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