Ford Mustang Forum banner
1 - 11 of 11 Posts

· Registered
Joined
·
11 Posts
Discussion Starter · #1 ·
I put a 98 mark 8 into a 03 gt. I read somewhere on here that I will have to swap the polarity on the cop`s. Does anybody know for sure if I have to do this, or are they fine the way they are ? Anybody know where I can get a 98 mark 8 throttle cable bracket, and an imrc pigtail ?
 

· Registered
Joined
·
6,859 Posts
question?

Where did the PCM, wiring harness, and COP's come from?

If the answer is the PCM, wiring harness, and COP's came from the original car, then the answer to your question is no.
 

· Registered
Joined
·
7,335 Posts
As someone who has worked through this issue before, here's the correct answer:

If you use the COPS from the 4V with the 2V wiring, yes, you need to switch the polarity. You can also trim down the tabs on the 2V COPS and use them as is. I just don't like the way they fit trimmed down.
 

· Registered
Joined
·
11 Posts
Discussion Starter · #6 ·
Yes, the cops have the same connectors, and plugged in without any problem. When I got the car it had a 2000 5.4 sohc that was locked up. I found the 98 mark 8 with 53,000 miles for $500 and switched all of the sensors and stuff over from the 5.4 and used the complete wiring harness from the gt. Some of the wires were too short and had to be extended, but aside from the alt plug everything plugged right up. I just was not sure about the polarity issue and wanted to get it straight so I can finish the wiring harness and fire it up without too much cranking and testing. Aside from a missing throttle cable bracket and intake tube it is complete and almost ready to start. 290 hp and Spec stage 1 billet flywheel and clutch set. New slotted rotors, ceramic pads, and 50`s all around. Why is the polarity different from the 2v and 4v, or from the mark 8 to the mustang ? Why didn`t ford just make them all the same ?
 

· Registered
Joined
·
7,335 Posts

· Registered
Joined
·
11 Posts
Discussion Starter · #8 ·
Found that site yesterday morning. Switched the polarity & lengthened the wires. I`m down to a few elec connectors I haven`t figured out yet, and the vacuum routing.
The gt alternator plug has 2 wires and the mark 8 plug has three. What do I do with the extra wire (black) in the middle ?
Another all-nighter and it should be ready to fire up. My biggest hold up is the lack of a throttle cable bracket and the intake tube to finish the swap. Thanks for the info.
 

· Registered
Joined
·
7,335 Posts
2 of the wires are connected together. Had the same problem putting a Bullitt alternator on a GT, and 2 of them are connected together. When I get a chance, I will figure out which two.
 

· Registered
Joined
·
6,859 Posts
FWIIW, the wiring diagrams for the 98 Mark VIII and the 99-04 Mustang show:


Function.M8-color.Mustang-color
B+.......BK/O.....BK/OG
A........Y/W......YE/WH
I........LG/R.....LG/RD

From the wiring diagrams, both alternators are similar in control functions.

I have help someone on another forum with a purchased Mach 1 conversion harness. The Black wire with the white stripe (BK/WH) was not connected to anything (which is OK). The problem with the conversion harness turned out to be reversed "I" and "A" lines. So these do make a difference and if reversed, the alternator will not active and generate.

Frankly, I don't think it makes a difference one way or the other if the BK/WH is connected or left hanging.
 

· Registered
Joined
·
11 Posts
Discussion Starter · #11 ·
To operate the imrc`s I have a window switch and a dis tach driver. Somewhere around my shop I have a diagram to connect the window switch to a imrc pigtail, but nothing to tell me which wire to connect the dis tach driver to the source it needs for it`s input. Can you tell me where to connect the distach driver ?
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top