Ground Wire From Firewall

Hey Tacoma World! So I had my motor replaced last fall at a shop after an unfortunate hydrolock of the original motor. When I got it back, there was a lot of wiring that kind of just got slapped back together. One of the wires hanging from the firewall just wasn’t attached at all (see attached photo).

Fast forward to today, I’ve had an annoying knock sensor P0330 code and finally have the time to dig in to make the repair. I have two new OEM sensors and a new wiring harness to go on. While I’m on there and have the whole top half of the motor off, I was hoping someone might be able to tell me where this ground attaches to? I’d like to hook it back up while I’m in there, even if it is redundant as the truck runs fine without it.

Thanks for the time and assist on this one!

 

Location for a 4 cylinder truck. Should be a similar spot somewhere on the back of the engine block.

 

The ground wire afixes on the rear of the P/S cylinder head and IIRC was with a 6mm bolt.

As an observation, those allen head bolts that you are using to hold the downpipe to the P/S exhaust collector are going to be a real problem in the future to remove.

 

Thanks for that ground wire routing help ciaman96 and Glamisman! I’ll update after I’ve gotten everything back together. I’m hoping the existing wire is long enough, but seeing as how it’s frayed, I’m guessing I won’t be luck enough to be able to just crimp a connector on it to bolt back up.

As far as the downpipe bolts are concerned, are you thinking just a regular nut and bolt would be best? That’s how the shop gave it back to me, I’m guessing the stock bolts were pretty corroded after 25 years of heat on them.

 

Yes regular nuts/bolts should be "good enough". The problem with allen bolts is exactly what you mentioned, after years they sieze and you cant get enough of a bite on an allen head to loosen it without the allen stripping.