Power seats and gearshift problem

[KIRK343]

I have a couple of issues with my 03 MM. First of all, for no apparent reason, my power seats quit working on both sides. I've checked the fuses under the dash and the 602 relay seems to be ok under the hood. I switched it out for the relay for the power windows and it worked fine. My power pedals and power tank lid quit working also. I've thought about checking power to the switch and motor but don't know the best way to do this.

My second issue (while trying to fix my seats) occurred as I tried to back my car out of the garage. My shifter is stuck in park. The only way I can get it out is if I turn my key to assessory then shift to neutral.

Can anyone help me (I know I'm an idiot)

[fastblackmerc]

I have a couple of issues with my 03 MM. First of all, for no apparent reason, my power seats quit working on both sides. I've checked the fuses under the dash and the 602 relay seems to be ok under the hood. I switched it out for the relay for the power windows and it worked fine. My power pedals and power tank lid quit working also. I've thought about checking power to the switch and motor but don't know the best way to do this.

Check the "mini fuse" #602 - 20A under the hood. It may "seem' to be good but looks are deceiving.


My second issue (while trying to fix my seats) occurred as I tried to back my car out of the garage. My shifter is stuck in park. The only way I can get it out is if I turn my key to assessory then shift to neutral.

Can anyone help me (I know I'm an idiot)

You do know you have to depress the brake pedal top move the shifter out of PARK.

Do your brake lights work? If not, you can't shift out of PARK. These fuse(s) could be blown (#16 - 15A or #19 - 15A or # 22 - 20A).

How did you check the fuse(s)?

FYI. test the fuses with a test light. As these cars age there can be corrosion built up especially in the power distribution box under the hood.

[KIRK343]

Yes sir. i meant to put even though I push the brake pedal down it won't shift out of park. I haven't checked the tail lights. I assume this could mean the break light sensor is bad u set the pedal?

Also, I just simply pull the fuses out to check. No way really to check the relay right?

[fastblackmerc]

Yes sir. i meant to put even though I push the brake pedal down it won't shift out of park. I haven't checked the tail lights. I assume this could mean the break light sensor is bad u set the pedal?

Also, I just simply pull the fuses out to check. No way really to check the relay right?

The brake light switch and wiring could be bad.

Check the fuse with a test light. With the ignition on you should have power on both sides. Test a relay by swapping it out with a known good one.

[KIRK343]

Ok, I've taken a test light and started my car. I pulled the 602 20a fuse out and the test light lit up when I touched it to one side of the place where the fuse was but did not light up on the other side. I'm guessing this is normal?

Also, my brake lights do not work. Should I replace the brake light switch?

[Spectragod]

Ok, I've taken a test light and started my car. I pulled the 602 20a fuse out and the test light lit up when I touched it to one side of the place where the fuse was but did not light up on the other side. I'm guessing this is normal?

Also, my brake lights do not work. Should I replace the brake light switch?

You need to verify continuity of the fuse with a meter while it is removed from the car. Analog or digital meters are fine.


You can use your test light to verify voltage to the brake light switch, and then, verify 12v+ out on the other side of the switch when it is depressed. You car will not need to be started for this, as the circuit has 12v+ all the time to it.

[KIRK343]

Ok just a little update. I was indeed my brake light switch. Thanks everyone for all the help.

I also switched the circuit breaker under the hood that controls the power seats and pedals. No luck there at all. I've also unplugged the wire going to the power seat motor on the driver side and still no luck after I plugged it back in. How can I test to see if power is even coming to the motor?

[Spectragod]

Ok just a little update. I was indeed my brake light switch. Thanks everyone for all the help.

I also switched the circuit breaker under the hood that controls the power seats and pedals. No luck there at all. I've also unplugged the wire going to the power seat motor on the driver side and still no luck after I plugged it back in. How can I test to see if power is even coming to the motor?

Test it the same way, measure for 12v+ when activating your switch. If both seats are dead, then it is more than likely a fuse, fusible link, relay or breaker bad.

[KIRK343]

Ugh....today I tiok my door panel off and used a test light first to check power going to the motor under the seat. None there. Then I tested the wires going to the power gas lid actuator and also to the wires goi g to the power seat switch. No power. I didn't bother to check the passenger side. I assume no power there either. I have actually replaced the relay under the hood with a new one. Is there anything else to check? I'm perplexed

[KIRK343]

Just wanted to let everyone know that after being very close to giving up on the power seat problem, I decided to take off the passenger side door panel to look it over. Lo and behold I found the wiring harness going to the power seat adjuster was somehow crimped to the point that two of the wires in the harness were almost broken in two. A little black tape and I was back in action.

[fastblackmerc]

Just wanted to let everyone know that after being very close to giving up on the power seat problem, I decided to take off the passenger side door panel to look it over. Lo and behold I found the wiring harness going to the power seat adjuster was somehow crimped to the point that two of the wires in the harness were almost broken in two. A little black tape and I was back in action.

You'd probably want to do a more permanent fix for the "almost broken in two" wires. Like solder and heat shrink tube.

[jmsa540]

Just wanted to let everyone know that after being very close to giving up on the power seat problem, I decided to take off the passenger side door panel to look it over. Lo and behold I found the wiring harness going to the power seat adjuster was somehow crimped to the point that two of the wires in the harness were almost broken in two. A little black tape and I was back in action.

Any writeup on how you did this? My passenger seat doesn't want to budge and the switch isn't drawing power.

[fastblackmerc]

Any writeup on how you did this? My passenger seat doesn't want to budge and the switch isn't drawing power.

All you need to do is take off the door panel.

[Spectragod]

Power for the switch and seat are fed from the same place. Check for voltage and ground at the seat.

If it exists there, check for voltage at seat when switch is operated, if it is there, the motor assembly is bad.

If no voltage present, check relay, fuse, fusible links etc.

You will need a DVOM, and some jumpers.


Sent from my iPhone while doing a big ole' smokey burnout in my wife's Prius.