Re: Making some head way on the '66
Ok guys, you're going to love this one, lol... I got the steering thing all ironed out and all is good there, so, going to take her on another shake down cruise to see how she goes... so, the first thing I notice is that it seems like the transmission is slipping. I have a 3200 stall but it still just didn't feel right so I back her up and put her back in the shop. Check the trans fluid, all is good, go to the display for the TCI EZ-TCU and I have 3 errors, a TPS error, trans over heat error, and trans sensor shorted or open. So, evidently due to the errors the trans went into limp mode and was trying to take off in 2nd or 3rd gear.
The odd thing, one of the odd things, is that I can't clear the error codes with the hand held like it's supposed to do. I have no clue why that is. So I start down a check list of things to check, grounds, loose connections, plug on the trans inserted properly.... all good. So I remember reading about electrical noise potentially being a problem, so I decided to move the TCU from under the dash, near the ECU, to under the console.
So I start dissecting all of the wiring and begin rerouting everything. However, before I started I disconnected the battery, both the positive and the negative sides. My theory was that I would then add one thing at a time, only adding those things necessary to power the ECU and TCU and see if I could resolve the issue. But one time while doing this I forgot to reattach the negative ground cable to the lug that ultimately grounds the battery to the chassis. I went ahead and checked the TCU, turned on the key and had only 1 error, the trans was over temp, but I was able to clear it with the hand held now. Then I noticed that the ground cable was off so, thinking I was about to solve this issue I shut everything off and connected the ground cable and went back to see the results. Again, turned on the key and had all 3 previous error messages again and was unable to clear them with the hand held.
So, I finished wiring everything else back up and connected the ground, checked again, same thing, 3 error messages and unable to clear them with the hand held. So, I thought that I disconnect the ground cable again just to see what would happen. I did, turned the key on again and lo and behold, no error messages and for the first time it appeared that the TCU display was actually displaying the correct trans temp, 86*, TPS read 0, as it should, and the volts for the battery was correct.
I have a crap ton of grounds but what I don't understand is how I'm getting any power to anything when I take the primary ground cable off the battery and there is no ground connected to anything. I realize that I have my ECU and TCU, as well as my A/C and other things that required me to run both their positive and negatives directly to the battery and there are some additional grounds off of those harnesses that are grounded to the engine and or body, but, without the battery directly connected to a ground source I'm at a loss as to how anything gets power. More so, I'm at a loss as to why the TCU functions properly with this ground cable disconnected, yet, when hooked up properly it flashes errors which you can't clear with the handheld.
Starting to pull my hair out here as I've never seen anything like this before. Any clue as to why this could be happening? Of course I called FAST today but I imagine because of the Power Tour they are short staffed as I haven't heard back from them yet. Any and all suggestions would be welcomed and appreciated!
1966 Malibu, 540 BBC FAST XFI EFI, 4L80E Trans, 2800 Stall, Quick Performance 59" 9" Ford Rear End w/3.50 gear