Contour Enthusiasts Group Archives Forums General Troubleshooting Weird problems caused by wiring??

I'm 99.9999% sure that wire they have you cutting is connected to the battery or somewhere close to it and is connected to the regulator so it senses the voltage at the battery.

The modification has the wiring modified so the regulator senses the voltage at the output terminal of the alternator.

Why was it done that way from the factory? The wire between the output terminal of the alternator and the battery has voltage drop depending on the amount of current running through it. Sensing the voltage at the battery allows the alternator to compensate for this voltage drop.

It might be worth the effort to run a new wire from the battery back to the regulator (the 3-terminal connector). Or at least disconnecting the old wire so it doesn't short out.

You are 100% correct, but as to why they did not do it in the first place, you could also ask why they did not perceive that wiring gets old and resistance goes up, thus causing a higher voltage drop across the same wire. You can also wonder why they chose cheap wiring. either way Ford knows about it and thats why they had a TSB.

You can just run a new wire, but why would you? If FORD already knows the fix.

What I read (I believe it's the same TSB you're talking about) said to run a new wire.

I know why it was done the way it was in the first place.

I re-read the TSB and it seems pretty clear that it says the problem is in the wire between the battery and the alternator output terminal, not the reference wire.

If the reference wire had a high enough resistance and if the regulator pulled enough current through the reference wire to cause a severe voltage drop, it could cause this problem. But I do not think that the regulator draws much current through the reference wire--it likely only draws a very tiny amount (milliamps).

If the reference wire had an intermittent connection that would also cause this problem, regardless of current draw.

An interesting test would be to turn as many electrical loads on as possible and measure the voltage between the alternator output terminal and the positive battery terminal. The displayed voltage is the voltage drop. I suspect it's pretty high on the cars exhibiting this problem.

Ohh OK, well then the new wire is a bypass, you cut the old and leave it unused then you new wire will go from your alt. output to the voltage reg of the alt.

Here's the story on the wiring harness problem. I had both my tours done years ago. A relative of mine worked for a sneaks engineering company that was hired by Ford to solve some of their hardware and software problems several years ago. He got to know the Engineers at Ford real well and they told them this horror story. Back in the early 90s Ford, in their effort to save some money, cut the quality department out totally. These are the folks that take products made by numerous vendors and test them to see if they meet spec. They also compile records of problems reported by dealers and seek to resolve them in a matter of weeks. Instead it took years to fix the parts. Remember the pre-cat problems on the 95s? If someone would have tested the manifolds only a few hundred cars would have had this problem - not 2 years worth. As for the harness. The vendor used the incorrect plastizer in the insulation formula. Cars in the south, expecially ones near the Gulf, had the insulation falling off 2 years later. Water pump is the same story. Someone decided to color the 2.5s impellers black as no to confuse them with other pumps. The dye caused the plastic to degrade prematurly. It tool a few years to catch this one. Where was their savings???

When I removed the computer harness from my brother's 1995 Ford Contour V6, I noticed that the wires connecting to the knock sensor were in perfect condition. No cracking at all.

I think somone got the 160C GPT (general purpose thermoplastic) wire spools mixed up with the 300C TXL (thinwall crosslink) wire spools, but that's just my theory.

By the way, the wiring harness vendor is Yazaki. They are a Japanese company.

Terry Haines mentioned that they were made by Yazaki, and when I looked at their webpage, their logo (the triangle) was already familiar to me because it's on many wiring connectors used in the Contour.

I sure would like to know why this crap wiring didn't find itself into any other cars other than the Contour/Mystique.

Actually, the 1995 Mercedes E320 supposedly also has the same problem..wonder who made those harnesses?

There was no 100,000 mile, 10 year warranty for the wiring harnesses on the 1995 E320 either.