ST205 harness work with st185 Options

[wannarace]

I have a 94 celica GT and have a st185 swap in the car, current harness in there right now is messed up. My question is will a ST205 from a 1998 gt4 harness work in my 94 celica gt st185, or would it be too messy to modify the harness?

[lubu]

too messy IMO...better off with the 185 harness.

[alltracman78]

mmm, I don't know about that.
It actually might be easier to use the 205 harness vs the 185 one.
Aside from the RHD to LHD swap, which would be the same hassle with either harness, the chassis wiring would be easier for you with the 205 harness.

As far as the engine goes, the only real difference in wiring is the AFM/temp sensor.
The other issue you'll run into is re pinning the ECU end, but I don't believe that is a whole lot different either.

If someone has personal experience with this [I don't] feel free to correct me.

[scothaniel]

Using the engine harness that matches the car is generally better, as you dont have to mess with the fuse block.

As alltracman78 stated, the main difference is the AFM & temp sensor. You'll have to pull the connector off your existing 185 harness and wire it in.

Another (minor) wiring issue will be the sensors on the coolant neck. The ST185 has 3 sensors (temp for ecu, temp for guage, temp for A/C) and the ST205 has 2 (temp for ECU/gauge, temp for A/C). You'd have to run an addition line for the added temp sensor.

There's also the EGR, but thats not a big deal.

[alltracman78]

Only the 90/91 has the AC temp sender, but both have the CSI switch, which you can do without, and the wiring used for something else.
However, I hadn't realized the 205 used [I assume the EFI temp sender?] a different sender for the temp gauge than the 185, good to know.

[wannarace]

So this using this harness on my 1994 celica with St185 motor will might just work?

[lubu]

My friend had the same problem as you and she tried to use 205 harness, ran into a number of problems. I'd think that it would be easier to use the 185 harness since your car is already configured for it??

[scothaniel]

Yeah, it really does depend on what changes have already been made to the stock harnesses - especially the main body harness with the fuse block connections.The fuse blocks in the 5th and 6th gens are completely different, as are the dash connectors.

I have an ST185 with an ST205 swap, and an AT200 with a ST205(ish) swap. In my st185 car, the stock harness was heavily modified for an EMS before the motor swap, so I tried to use the spare 205 harness and fuse block. I spent days trying to map out all the fuse block and dash connectors - it was a nightmare. I was lucky and found another stock 185 harness and ditched that project.

For the AT200 (ie 7AFE model) the stock harness was far too different to use with the 3S engine. By this time, I had cut into the 205 harness for another project so I couldn't use it. I had a 3rd gen 3SGE harness which is very much like the 205 harness, just needed to add a few wires to make it into a true 205 harness. All of the fuse block and dash connectors plug right in, but a couple of wires need to be moved around to make it work. I think it would have been easier if I had a GT Celica to begin with.

One lesson I've learned with the EMS install - dont cut into the stock harnesses if possible (re-pinning is ok). I make jumper harnesses when connecting 2 different harnesses together - like when putting a 7MGTE supra motor into a 2nd gen 4runner!

[lagos]

So this using this harness on my 1994 celica with St185 motor will might just work?

NO. The st205 harness will not work with your st185 motor.
You CAN make it work by rewiring a few things, but by itself it wont just plug in and work.