1995 Camry 1MZ-FE Engine Wiring Problem
 

I am putting a V6 1MZ-FE engine out of a 1994 Camry XLE into my 1995 Camry LE with the same 3.0 V6 engine type. Unfortunately, the wiring harnesses are different. The 1994 has a single cooling fan driven from hydraulic fluid from the power steering pump. My 1995 has two electric radiator cooling fans operated from relays in the relay block in the engine compartment. Most of the wiring connectors are the same, but the wires connecting to the various pins in the connectors are different. Unfortunately, my 1995 wiring harness is badly damaged, or I would simply put the 1995 wiring harness on the 1994 engine. Would it be better to buy a used 1995 wiring harness or to cut and re-wire the incompatible parts out of the 1994 wiring harness?

Might first determine what parts can be swapped from the 95 engine to the 94 to make the engine as close to a 95 as possible.

You should be able to incorporate the electric fan system.

Have you determined if there is going to be problem mating the 94 connectors to a 95 harness. Perhaps a 94 sensor, etc has 3 wires instead of 2, how do you connect the extra wire?

How badly damaged is the 95 wiring?

The engines are identical (temperature sensors and all). The problem is that the 1994 engine has the wires from the temperature sensors routed into the cabin to a hydraulic fan controller next to the ECU behind the glove box. Whereas the 1995 engine has the temperature sensor wires directed to the relay block on the left side of the engine compartment at the other end of the engine wiring harness from the 1994 engine. The 1995 wiring is not salvageable - it is badly corroded in places with numerous intermittent electrical problems I have been unable to trouble-shoot over several months (and several mechanics) of tinkering. I feel if I were to re-use the entire wiring harness from the 95, I would be transferring all my electrical problems to the new (1994) engine.

You answered your own question in stating the amount of time spent trying to make the current wiring work. Corroded wiring can be a major headache and once fixed you could very well have more problems in the future as the wiring ages.

If you can find a good harness agree this would be best. As you state your issues would then be narrowed to the engine. Why have more headaches in getting this car fixed.