Grab electric from amplifier for power seats? (2 Viewers)

[BobbyKnobby]

I recently installed some awesome BMW 3 series powered seats in my FJ62. I rigged up a 555 timer as has been described here any other places to trick the computer in the seats into thinking they are connected to a BMW. (It’s really just an intermittent 5v pulse that keeps thr seat control from timing out and going to sleep)

My question is how to power these power seats. It should use accessory power - only functional with the key turned half way or fully on. I don’t particularly want to run new wires from the battery and hood up a new relay from the ignition to get power to the seats.

What I’m considering (and stop me if this is too janky), is to splice into the power that the previous owner had wired up for a stereo amplifier located under the back bench seat. The existing amp wire is thick / large gauge, and like the stereo, it’s activated in accessory mode.

I get that the seat motors will draw a lot of power when being adjusted, but that will be pretty infrequently. I figure the worse that will happen is the amp will drop out for the moment when the seat is being adjusted.

How stupid is this idea? Should I just pull wire the proper way and do this right, or is it reasonable to run the power seats and stereo amplifier on a parallel circuit?

 

[OSS]

Amplifier and seat motor running at same time may blow the fuse. I hope the circuit is fused.
The wire won’t melt, but the weak point will be the connection at the source.
This idea seems very “the PO did an insane wiring hack. What the hell was he thinking?”

 

[BurntToast]

I recently installed some awesome BMW 3 series powered seats in my FJ62. I rigged up a 555 timer as has been described here any other places to trick the computer in the seats into thinking they are connected to a BMW. (It’s really just an intermittent 5v pulse that keeps thr seat control from timing out and going to sleep)

My question is how to power these power seats. It should use accessory power - only functional with the key turned half way or fully on. I don’t particularly want to run new wires from the battery and hood up a new relay from the ignition to get power to the seats.

What I’m considering (and stop me if this is too janky), is to splice into the power that the previous owner had wired up for a stereo amplifier located under the back bench seat. The existing amp wire is thick / large gauge, and like the stereo, it’s activated in accessory mode.

I get that the seat motors will draw a lot of power when being adjusted, but that will be pretty infrequently. I figure the worse that will happen is the amp will drop out for the moment when the seat is being adjusted.

How stupid is this idea? Should I just pull wire the proper way and do this right, or is it reasonable to run the power seats and stereo amplifier on a parallel circuit?

My thread has a full section on the electrical for the BMW seats “the right way” (or my attempt). You can see how much power each motor pulls

 

[BlackCat]

Amp power should come directly from the battery and while it should be sufficient to power the seats it will not or should not be fused accessory. The fused accessory wire that should be only powered with the key on is the remote wire, which will not power your seats.

Keep in mind most, if not all power seats can be adjusted with the key off.

 

[BobbyKnobby]

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Amp power should come directly from the battery and while it should be sufficient to power the seats it will not or should not be fused accessory. The fused accessory wire that should be only powered with the key on is the remote wire, which will not power your seats.

Keep in mind most, if not all power seats can be adjusted with the key off.

I was thinking that the fused accessory wire would flip a relay that would close a circuit allowing a direct line from battery to seat…not powering the seats with the fused accessory wire.

In terms of powering the BMW seats with the key/power off, my concern is that these seats need to be connect to power for the motors AND power to foil the seats computers to think they connected to the BMWs computers. I want to avoid a constant power draw (keeping the seat computer awake) for fear of battery drain.

I don’t want to be that crazy PO who jerry rigged something to be functional, but makes no logical sense for anyone else. I think I got my answer - wire it up proper, take the extra time to do it right!

 

[OSS]

take the extra time to do it right!

I guarantee you won’t regret choosing the correct path. There is a a certain satisfaction doing a wiring project top notch. It’s a really nice feeling.

 

[BobbyKnobby]

My thread has a full section on the electrical for the BMW seats “the right way” (or my attempt). You can see how much power each motor pulls

I just read through you build thread….dude! Inspirational to say the least! I got some good ideas on how to dial in my bmw seats too!!