The links I posted in my last post seem to have the right parts. I found these pictures that I took:

Have bought the connectors and body from Japan, and will post here when they arrive to confirm if they fit....

+41796877079

Pin for the D31 connector is Toyota 82998-12750 or -12760

The power plug housing is 90980-12300 - still looking to find a Toyota part number for the 9.5mm 312 connector it holds

+41796877079

I ordered parts from Japan as well and will post results when I receive them. However, the vendor sent me pictures and I am fairly confident that the parts are correct. 

Andrew

Quick post. The connector body from Japan was correct, but the terminals were not.

Andrew

With some Japanese language help, this seems to be the correct female terminal for the A19 connector housing that Andrew confirms is correct

From the same supplier as the housing to save by combining shipping costs

the correct terminal number from Rakuten f375-yz-s

 direct link is item.rakuten.co.jp/auc-hi-1000/f375-yz-s/

As this is linked directly from the connector housing page we are 100% confident it's correct 

For those outside the USA, the Toyota part numbers are not available in the European parts system, so I had to find a US supplier that would deliver to me in Switzerland. I found megazip.net.  This also has all the parts diagrams for all models online - they do seem to be very slow to process orders however.... 6 days since ordering and still not shipped.....

+41796877079

This terminal:

item.rakuten.co.jp/auc-hi-1000/f375-yz-s/

 is correct in that it fits the connector, however it is designed only for 12 gauge (3mm) wire. The correct terminal must be designed for 5-8mm wire. Thus far, that particular variant has been elusive.

Andrew

Not much to report in terms of progress or any other updates, however, I finally managed to track down the Yazaki part numbers for the big power connector for the steering ECU. The same connector is used on both the Prius and the Yaris steering ECUs (and probably others of the same vintage).

The connector housing body is 7283-3521-40





The terminals are either 7116-3097-02 or 7116-3098-02 (either will probably work).





The big challenge is sourcing the terminals in the US. The connector body can be purchased from Toyota under PN 90980-12653, however, Toyota does not sell the terminals.

I was actually able to source the connector housing bodies from Japan, but what I originally thought were the correct terminals, ended up being the wrong ones.

If anyone knows a source for Yazaki parts in the US, please let me know.

Andrew

"If anyone knows a source for Yazaki parts in the US, please let me know."

Just twist the wires together and wrap with masking tape! lol


"FREE SAMPLE"

I recently completed a 1000 mile road trip in the Cougar and I noticed that the steering was particularly numb on center. While driving down the highway I found myself having to constantly steer it in order to keep it going straight. I attributed this mostly to the windy conditions that I encountered at various points on the trip, but I didn't give it much more thought.

After getting home, I noticed that there was a little squeaking noise from the front end when I made slow right hand turns. I suspected that maybe the preload on the front bearings has loosened up, so I jacked it up to investigate. Rocking the wheel at the 12 and 6 o'clock position really didn't show any unusual looseness in the bearings, however, I did find significant slop when I rocked the wheel at the 3 and 9 o'clock positions:

https://www.youtube.com/watch?v=PcJwicXdsmc

Although all of my front end components are "new" they do have about 15K miles on them since installation. After seeing the slop in the rack, I called TCP and was surprised and pleased to get a live tech guy on the line. His name was Mike and he was very helpful. He told me that due to the straight cut gears of the rack and pinion gears, periodic inspection and adjustment is necessary to minimize the backlash. He outlined the procedure and I went outside and did it. I also noticed that the passenger side inner tie rod was a little loose where it was bolted to the rack, and I was able to address that.

Needles to say, the steering feels much better. The return to center is much improved and the on center feel is also much better (no duh...considering how much slop was there)! I plan to have the car up on a rack in the near future to inspect all of the steering and the suspension components and fix anything I find.

Take away: don't assume everything is tight and working properly just because all of the components are "new."