So, my current 1986 DLX 4runner has some engine harness repairs that are less than ideal. I mostly cleaned it up but it's not really following it's factory path anymore as far as the shape of the harness and things are stretching to reach certain components and I know it's not going to last like that. My current harness has the yellow 10,18,14 pinout scheme so I've been trying to find an EFI harness that will match my cowl harness but so far I've purchased two from online parts suppliers and both have been the same with the connector from the engine harness to the cowl harness being much wider and having more wires than the connectors on my existing dash cowl harness. The connectors from the harness to the transmission for the 4wd and reverse lights don't match up either.

I assume some of the extra wires might be for power features like power windows which my truck doesn't have but I'm not sure. How many different version of this harness are out there? Have I unknowingly purchased two SR5 harnesses and they are not working because I have a DLX or something like that? I can't find any info in search other than posts from a few others who have had trouble finding the right harness. This is getting a bit ridiculous and expensive to figure out. At least I know someone will eventually want these harnesses. Anyway, if anyone has any insight on this or on ways to get these to play together please let me know.


Thanks!

 

the picture of the harness connected to the ECU is my current setup and the other image is of the connectors from the other two harnesses.



EDIT: I did a bunch of wire testing because the connector that is pictured in my hand above has all the same wires within the center 16 pins ...the outside wires on each side of the two divides in the connector are not needed to make connections to anything in my truck. so basically the center 16 pins nearly match my cowl harness perfectly and on the harness that I already hacked I broke off the sides of the connector and it all fits right in almost like it is supposed to be that way.

The problem is NO STA signal from the replacement harness to the existing cowl harness and the truck didn't start when I tried this previously. I didn't have a lot of time to troubleshooting it at the time so I just swapped back in my old harness. Now that I took the time to dig into it I understand why I was having problems getting the truck started. My original EFI harness has STA on the 10 pin connector like it is supposed to, coming off the ECU and then it loops up to the 10 pin connector that mates with the cowl harness. The replacement harness doesn't make that same loop connection so thats why I got no STA signal and a no start condition. Also the replacement harness loops the IDL signal in a similar way that my old harness loops the STA signal so those are a couple of real issues considering the truck needs STA to start and IDL for the TPS to operate properly. I'd have to do some jenky-ness to make those connections and that sort of defeats the purpose of why I'm trying to install a better harness in the first place.

Honestly at this point I'm considering just investing in some crimpers and building a whole new harness from scratch.

 

Is there a part number sticker on your original harness?

I sort of went through the same thing on a 1997 Toyota Camry. There were many different versions of the wiring harness, even different between if it was assembled in the USA or in Japan.

If there is a part number sticker on your original harness, you could match it up to a good used harness of the same part number.

 

Unfortunately the harness is such a hack job that I don’t see any part number on it.

 

As far as I know, all the first gen 4Runners were assembled in Japan.
I'm in Europe, I have 2 1988 4Runners SR5 22RE IFS (the pickups came with SFA until 1988 here), and I got the 1988 FSM from US, the electrical schematic in the US book doesn't match 100% with my EU trucks wiring.

 

Yes, you are correct. I was referring to the differences with the Camry I was working on.