A Variety of BMW E34 Questions

[Gabe]

Where are the door sensors located on each door?

What is the best way to route a power cable from the engine bay through the firewall to the rear of the vehicle?

When looking under the hood, what is to the bottom right of the air filter (another large tube) that hangs lower and close to the engine, right above the alternator.

More complex issue:
Where does the factory amplifier come into play with the factory speakers? I have the BMW wiring harness for installing my aftermarket headunit. It has all the speaker leads accessible also. I figured I can run the rear speaker cables directly to the amp considering the short length. With the front speakers, however, I am not sure how to wire them up to my aftermarket amplifier... I purchased components for the front, 5 1/4s in the door, and the tweeters I put in the dash (not the pillars) How do they wire together? Also I have a short segment of cable which needs the resistors for the tweeters, I assume I will just install those through the top of the dash. If I connect speaker cables to the harness adapter, will the amplifier still kick in? Is it smarter to get the connector off the factory amp and get the front speaker outputs from there?

Any other tips and tricks on getting the RCA and power cables across the length of the car as efficiently as possible?

Having fun working with this car;

Thanks

[borderchris]

The other tube is your alternator cooling pipe, and as far as routing a wire, the easiest is through the main grommet / seal that carries the accelerator cable- just be sure to re-seat the grommet properly. If you straighten out a metal hanger, tape the end of your wire lead to it and feed it through.

Not sure on the door switches....


Chris

[DaveVoorhis]

When looking under the hood, what is to the bottom right of the air filter (another large tube) that hangs lower and close to the engine, right above the alternator.
Do you mean the tube that connects to the back of the alternator? It's the alternator cooling tube.

[stargazer_61]

Gabe - Fill out your profile. Forum members need to know the year and model of your E34 to better answer questions.

[Paul in NZ]

the door "sensors" (switches?) are located on the latches,a little switch pad about the size of a match head

[shanek]

I'm going to presume you have an early 525I same as me. There is power under the rear seat so you don't need to go through the firewall.

[Gabe]

I'm going to presume you have an early 525I same as me. There is power under the rear seat so you don't need to go through the firewall.

Does that apply for the M50 engine? Is this connection adequate to power ~600 watts?

[Gabe]

Gabe - Fill out your profile. Forum members need to know the year and model of your E34 to better answer questions.

Thank you for the 411, did I do it right?

[shanek]

I think all e34s are wired for a battery under the rear seat. I presumed thats why the power connection was there in mine. You should be able to hook up any amp you want.

[Gabe]

I think all e34s are wired for a battery under the rear seat. I presumed thats why the power connection was there in mine. You should be able to hook up any amp you want.

Ugh, I just found it, after running a power cable the whole length of the car :(

In essence though, with a stronger alternator, I'd be able to have two batteries?

[joshua43214]

I am not really sure what you are trying to do with the stereo. I get the idea you have a new amp that needs wiring, is this correct? Does the amp accept high power input? if not, then you cant use the factory wiring from the head unit to the amp.

I just ran all the cabling for my car fresh and the only factory wires I used was for the headunit power, keep alive power, and antenna power. remove the entire back seat, and one of the front seats. remove the entire center console. Flip the rear carpet up and over the hump, and raise the front carpet as much as you can, then you can run the wires from the trunk to the head unit with ease. There are gromets behing the rear seat rest that you can punch out to add wires. Took me about 2 hours to run a bundle of wires that was about 1inch in diameter. The job isnt really as bad as it seems, and is worth it for a nice clean install.

There are a ton of threads for modifying the factory amp on this forum. If all you are doing is running a sub w/ amp, you can probably just take the signal form the amp in the trunk and save yourself a ton of hassle. It really all depends on what you are trying to do, so maybe let us know what you have in mind and you can get some more accurate feedback.

You can probably run 2 batteries with the factory alternator, but you are far from needing anything so fancy with only 600amps, just get a good battery that meets OE specs, don't skimp. I recomend Delco, should run about 100 bucks or so. 2 batteries requiring isolating, this is a headache you probably dont want to get into, unless you plan to do a huge stereo or install a fridge.

[Gabe]

You can probably run 2 batteries with the factory alternator, but you are far from needing anything so fancy with only 600amps, just get a good battery that meets OE specs, don't skimp. I recomend Delco, should run about 100 bucks or so. 2 batteries requiring isolating, this is a headache you probably dont want to get into, unless you plan to do a huge stereo or install a fridge.

Thank you for atleast buying into my dork pychosis... yeh, believe my battery maybe on its final days, if I leave the radio on with the car off, battery dies enough not to be able to start the car within 20 - 30 minutes. Delco sounds like a good brand, will wait until it gives me enough problems (ie I have to perform the emergency unlock procedure on the doors, LOL!)

[RichG]

What is the best way to route a power cable from the engine bay through the firewall to the rear of the vehicle?


I have a 90 525i and I am wiring up a couple of amps in the trunk. My battery is in the engine bay so I ran a power cable from the front to the back. From other threads, I thought it was going to be a real pain to get a wire through the firewall. After I removed the glove box, I noticed a corrugated-looking rubber tube against the firewall right above the kickpanel. Looking in the engine bay, I saw the same tube running into the ECM box. I removed the cover from the ECM box and then poked the wire up from the inside as far as I could. When I went around to the engine bay again, I saw the end of the wire! There is already a hole though the firewall from the ECM box to behind the glovebox. It was way too easy.

If anyone knows if this conduit shouldn't have a wire running in it or if a wire with a high current running through the ECM box will cause problems, please let me know.

There were even rubber grommets out of the ECM box up to the battery area already in place...all I had to do was cut them out for my power cable. I surely can't be the first one to find this existing hole.

[ktteoh]

richg, do you have some pictures of the route that you are suggesting?

[RichG]

richg, do you have some pictures of the route that you are suggesting?

I don't have anything already taken.

Basically the route through the firewall goes out the rear of the ECM box through an existing tube. I circled the tube in red in the realoem diagram that I have hopefully attached (never tried uploading a file before).

The top end is in the ECM box and the bottom end is behind the glove box to the far right side of the inside of the car (LHD). I can't remember if you had to take the side kick panel off or not to see the tube.

[Alexlind123]

I am not really sure what you are trying to do with the stereo. I get the idea you have a new amp that needs wiring, is this correct? Does the amp accept high power input? if not, then you cant use the factory wiring from the head unit to the amp.

I just ran all the cabling for my car fresh and the only factory wires I used was for the headunit power, keep alive power, and antenna power. remove the entire back seat, and one of the front seats. remove the entire center console. Flip the rear carpet up and over the hump, and raise the front carpet as much as you can, then you can run the wires from the trunk to the head unit with ease. There are gromets behing the rear seat rest that you can punch out to add wires. Took me about 2 hours to run a bundle of wires that was about 1inch in diameter. The job isnt really as bad as it seems, and is worth it for a nice clean install.

There are a ton of threads for modifying the factory amp on this forum. If all you are doing is running a sub w/ amp, you can probably just take the signal form the amp in the trunk and save yourself a ton of hassle. It really all depends on what you are trying to do, so maybe let us know what you have in mind and you can get some more accurate feedback.

You can probably run 2 batteries with the factory alternator, but you are far from needing anything so fancy with only 600amps, just get a good battery that meets OE specs, don't skimp. I recomend Delco, should run about 100 bucks or so. 2 batteries requiring isolating, this is a headache you probably dont want to get into, unless you plan to do a huge stereo or install a fridge.

O_o