Tom M'Guinn

My 15-year-old 044 fuel pump appears to be going bad. It started marking way more noise than ever. It now sounds a lot like the open door buzzer on the 951. It's relatively quiet when cold, but after 10-20 miles, it just screams now. So.... I decided to try AEM's 044-style replacement (PN: 50-1009). It's a drop-in replacement for the 044 that purports to have more flow (and is not as noisy some say).

https://www.aemelectronics.com/produ...flow-fuel-pump

Although the current draw appears to be in the same range as the 044, they list a max draw of over 17 amps (most sources list the 044 at 13 amps), so I'm going to bite the bullet and wire it in with 10 gauge wire and use the factory wires to trigger a relay. I doubt I'd see the max 17 amp draw, but didn't want to risk it. The factory wiring has been fine with the 044 pump, but it runs through a 15 amp fuse and ~16g wire, so didn't want to push that any further. After pricing out all that, there's was no way to do better than AEM's own relay/circuit breaker kit, so I got one of their 30-amp relay kits (PN 30-2061):

https://www.aemelectronics.com/produ...ay-wiring-kits

Any wire-routing advice from those who have done this? I'm not a fan of the open posts on the circuit breaker, so will probably end-up 3D printing an enclosure for that and mount it in the battery box. I'm inclined to put the relay inside somewhere, probably in the rear hatch area, either by the rear ground point or side well under the carpet and above pump. I'll have to dig in, but curious how others have routed the wires out of the battery box and toward the rear. Under the car? Inside like stereo am wires? I'll post my progress here, though it will likely take a little while.

Scott H

I ran from the battery box, through a grommet, into the passenger footwell (where I put the relay, there's a good spot for it right behind the carpet that makes it easily accessible, I'll grab a picture tomorrow), then down the passenger door sill under the carpet, then under the back seat carpet. What I can't remember is where the wire punched out to the fuel pump but it was somewhere behind the rear passenger seat. It wasn't too difficult, but you'll want some fish tape to get the wire from the rear of the passenger door sill to behind the rear passenger seat. When I did it I ran a smaller wire back up to the relay from the existing FP wiring to trigger the relay, if I had to do it again I'd find somewhere further upstream (under the dash) as it'd make for a much tidier install.

Tom M'Guinn

Thanks Scott. I was sizing it up today and came up with a similar plan. No back seat here, so that should help a tad. My plan was to put the relay in the rear hatch well so it would be close to where the original fuel pump wires terminate. And run the positive wire in above the glove box like you did and snake it down the side under the carpet and door sills. I need to roll up my sleeves and get to it, but still waiting on a few parts...

Scott H

Here's a picture of where I hid all the crap, there's a surprising amount of room behind that carpet. If you have a non-ABS car then there should be tons of room there. Not the tidiest but what can I say, I did it 10 years ago in a rush, I really should clean it up sometime (routing the 10ga away from the ABS loom would probably be smart too). Takes ~10 seconds to access in case the fuse or relay blows, that's why I decided to place it there.

Tom M'Guinn

Thanks Scott! Looks good. I'm sure that will outlive the car.... I'm hoping to put the little little circuit breaker super close to the battery so that 10g positive wire is protected where is goes through the firewall. The one AEM supplies resets itself if it trips, and I'm still trying to figure out if that's a good or bad thing. At least when a fuse blows, it's obvious that is blew...

Scott H

I'd probably just wire in one of those waterproof inline fuse holders in the battery box then just to keep it simple, the good ones with the rubber seal like the HHU Waterproof one here http://www1.cooperbussmann.com/6/Bla...cessories.html I didn't see the need to fuse before the firewall because the wire got run through a grommet with a bunch of other factory wires so I fused it on the other side of the relay inside the car. That fuse holder only has 12awg wires but so long as you keep them short as possible you won't have an issue, voltage drop over a couple inches will be essentially nothing. If you pop the fuel pump fuse twice in a row you likely have greater problems and should just call a tow. I do have a circuit breaker on my aux. fuse panel that's in the driver's footwell (getting power from one of the lugs on the fusebox), but that's feeding multiple fused circuits.

Tom M'Guinn

You're right. I just ordered an inline fuse from Amazon. One less thing to mount, and keeps it simple. I thought the circuit breaker that came with the AEM kit was cool, but it adds complexity for the sake of complexity in this case... Thanks for pointing that out.

KevinGross

Tom, for the circuit breaker there are protective cap options such as VW/Audi 113971901A

Tom M'Guinn

Thanks Kevin. I actually started making a 3D-printed cover for the whole thing, but on reflection I think I prefer a fuse. One less thing to mount, yes, but also if the pump ever does trip the breaker/fuse, I think I'd prefer the tattle-tail fuse than a circuit breaker that resets on its own and leaves me guessing. It's a close call for me though, and I may change my mind on the side of a freeway someday.

Tom M'Guinn

My new 10 gauge pump wiring is done and working. Here's how I did mine...




I attached the 10g wire to the positive battery post via a 30 amp inline fuse. I put a tight-fitting piece of curved hose in the grommet, ran the wire(s) through that, and then used heat shrink to seal it all. Had to remove the glove box to get to the other side, and routed the cable down the passenger side of the car...




The factory wires to the fuel pump come up through this hole in the hatch floor. I had to remove the grommet that was there, strip away some of the harness sleeve to free the fuel pump harness from the bundle of wires, and pull it up into the cabin, so I could use it to trigger the relay...




Here's the harness I made. The factory fuel pump harness has a connector under the car. I discovered this is the same connector used on the brake wear sensors, so i found an old brake wear sensor and soldered its connector to the control wires on the relay so that I could connect it all without cutting the factory harness. Sheathing is just what I had handy, with dual wall adhesive-lined heat shrink where needed.




Here's the harness in place. I routed the new 10 gauge wires down to the pump using the factory routing/positioning.




Rather than try to pull the entire cable, I cut a grommet and worked it into place in lieu of the factory snorkel-style grommet. It's reasonably well sealed as is, but I'll likely cover it all in duck tape or silicon...

huskeric

Tom,
Many thanks for posting this uber helpful diy! I just completed this on my car and eliminated the guess work of where the existing lines were located, as well as where to locate the relay.

perfect!

thanks again,
rick

SeaCay

FYI, Tom's gone.

gpr8er

gone?

SeaCay

From here, yes.

blade7

Why?