graylady

Thanks - I will check this and get back to you. It may take a couple of days as I am working late hours this week.

Please help!! I have a 98 Mystique with 83k miles. V6 with automatic. The motor locked up so we recently swapped the motor with a v6 from a 99 cougar. During the process the harness literally went to pieces. It was cracking before the swap, but the handling only made the harness worse. I found a harness from a 99 cougar in very good condition at a salvage yard. I installed it only to find that it is not compatible with the 98 computer. I also have what appear to be extra 02 sensor plugs on this harness. I need a harness that will work on my 98. Are there any possible vendors that can assist? Thanks for the input!

Where can I find a pin out diagram for a 99 cougar harness and an early 98 model mercury mystique harness?

I have found another harness that is from a 98 contour V6 SE. Is this a plug and play if I swap out again. The starter was turning over with the old harness. I believe this is a PATs or harness pin out issue with the neutral safety switch.

Thanks a ton for all of the input and ideas. I will get back on the car in the am and check many of the topics mentioned. I need to get this car rolling asap. I will check power to the starter first. I can hear the fuel pump prime. If the starter is getting power, I will remove it and have it tested.

I changed the pcm harness that has the injector harness and crank and cam sensor connections. I will add that the harness came from a 99 Mercury Cougar. Everything looks identical. I get the check engine light with key in the on position.

Trying to figure out why my 98 2.5L will not start. Automatic trans. No crank. Dash lights and check engine illuminate with key in on position. When I turn the key, the security light goes away. I hear a light click at the relay when the key is turned. This all started after I changed the harness to one in better condition because of the fraying issue. Before the harness swap, the starter turned over. All connectors except the 02 sensors have been made. I double and triple checked the 4 ground points. Battery is charged - terminals tight. I tried starting it in different gears. All fuses good. The 3 harness connectors near the pass side rear head are tight. Pretty much out of ideas and getting close to having it towed to a shop. Please help.

Thanks - we had 3 out of 4. We missed the lighter ground wire from the top of the bell housing to inner fender. Hopefully that is why she isn't starting. Changed out the harness. We now get the check engine on the dash, but when key is turned to ON - nothing. You can hear the fuel pump prime and thats it.

Just installed replacement 2.5l in my 98 Mystique. Where are the ground points for this engine/electrical system? I cannot confirm this was done properly. Thanks!

I bought a very clean v6 1998 Mercury Mystique with 83k miles. A broken rod locked the engine so I replaced it with a 2.5L from a Cougar. Every connector had exposed wires so I also changed the harness. I did not touch the pcm. With everything installed and plugged in, I am stumped. The 20A EEC fuse blows when the key is turned to on. The starter does not crank. You can hear the fuel pump prime before you turn the key to the on position. Where should I look next. All connections are snug. No exposed wires. Thanks for any input!!