Contour Enthusiasts Group Archives Forums General Troubleshooting Electrical weirdness: O/D, coolant light, random behavior

Calling all electrical system gurus! I have a 1995 Contour GL, V6, ATX, 102,000 miles. Two days ago things started going haywire. It's not a consistent symptom but basically:

I can start the car and drive a while and everything works fine. But if I turn on the wipers, or sometimes without doing so, the coolant light and the O/D (overdrive off) light will light up. They come on together and stay on. After this point, the O/D feature no longer works: pressing the O/D button has no effect. All other car systems work fine. The ATX continues to shift fine through all gears. If I turn off the car and let it cool a few minutes, it starts up fine until this all starts again after a few minutes.

That is the "main" symptom that happens consistently on every drive. But during a long drive yesterday I also witnessed the following things sporadically, each only one or two times, in no particular order:

- Coolant and O/D lights gradually fading/flickering to black;
- O/D light on and off when tapping the brake pedal;
- O/D light on and off in sync with pressing the defroster button;
- Coolant light flickering in sync with the wiper motor;
- O/D light coming on when driving over one bump once.

These symptoms were coming and going with no obvious trigger. Aside from O/D lockout not working (every time) there are no other problem actually running the car. The coolant level is safely above the Max line. ATX was recently serviced and has no slippage or rough shifts. Engine sounds fine. All exterior lights are good except I just found both license plate lights were burned out (and could have been for years). All interior fuses are good. (Haven't checked the under-hood fuses yet.)

Other possible clues:

- The brake/shift interlock failed several weeks ago. (See "Failed shift interlock solenoid" topic.) Dealer diagnosed it as a failed solenoid, said the whole shifter needs to be replaced for $600+. I haven't tested the solenoid myself yet. Pangloss (thanks!) posted information that the dealer may well not have tested the solenoid either, but just reached the end of the diagnostic steps where the manual says replace the shifter if all else fails. So there may be an electrical fault elsewhere else.

- I did open the console a couple weeks ago while troubleshooting the above problem (and finally just installed a rubber band to hold the solenoid open) but was careful to not damage the O/D wires and wiring harness in there.

- The clock light burned out within the last couple days though I didn't witness exactly when it happened. Quite possibly related to all this. Still keeps time.

- Over the past couple years, the (factory) radio has spontaneously lost its station presets about 3 or 4 times, many months apart. Once it happened while driving: I turned off the radio, turned it on later, and the presets were gone. The other times it happened when first turning on the radio after the car had been parked.

That's my story. Anybody have any ideas?

Scott, Pop the hood and take a look at the underhood wiring. Look for cracks in the insulation and exposed wires. I would take out the battery and examine the battery terminal connectors as well as the wires. See if they are deteriorated or loose. Look at the wiring going into the underhood fuse box as well as behind the under dash fuse box. There are alot of connectors going into the junction panels above the underdash fuse box. Make sure that they are all connected tight.

To be honest I hate chasing down electrical gremlins.

Scott-

I don't know if this will help, but here goes.

How old is the battery? When I was looking at my car on the dealer's lot, it had a weak battery. When I would try to start the car, all kinds of warning lights would be flashing, the engine would not crank, and then the windshield wipers would run one pass across the windshield. A quick charge cured the problem temporarily. When I came to pick up the car, the had to replace the battery. My first suggestion is to check the battery. [These cars seem to get strange symptoms with a weak battery.]

Second, as Lee suggested, check all of the wiring the best that you can. Unplug and replug all connectors a couple of times. Next, look for a loose or corroded ground connection. Take off the battery cables and clean the cable 'clamp' and the battery posts thoughly with some medium grit sandpaper.

Hope this helps.

Mike

Amen to what everyone else has already said because the randomness of your problems and their timing would seem to indicate the problem is with your primary electrical system (i.e. the battery) kind of cutting out and then back in again.

Check the battery terminals (for corrosion) and the wiring connectors at the terminals. Odds are they're the primary culprit in this.

Also, one thing you didn't mention is how old is the battery. Is it getting close to the time to replace it? A weak battery can still start and run the car but also cause all kinds of intermittant electrical problems such as those you've been having.
Believe me - I know - I've been there. On a 1983 Chevy Impala the only symptom I had was radio static which turned out to be caused by a dying battery too weak to run the car and the radio!

Just 12 months. The original battery lasted about 5 years.



From the Oh Good Grief department: the negative terminal has some white gunk, and the negative cable is completely loose! It looks like the dealer (the last shop to do work that would require disconnecting the battery) totally forgot to actually tighten the clamp. I could lift it off with my little finger. Unfortunately I didn't have a suitable wrench or terminal cleaning tool when checking this last night, so I'll fix this later today.

However, I wonder if that's the real problem. Though loose, the clamp did seem to make good contact and hadn't actually wiggled off the post. But under engine vibration maybe it does cut in and out.

With zero experience in this area, I'd have thought a flaky battery connection would cause more dire problems like lights and other major systems simply cutting out, rather than my elusive dashboard "gremlin" symptoms. However I'll clean and tighten it tonight and report back.

Hey Scott, Pangloss here again. Now your problems sound a lot more like mine: I had the O/D switch go out first, with some phantom flickering of the light, then the park interlock switch quit. Note my car is also a '95, but 2.0L.

If you don't turn up anything wrong with the battery or wiring harness, let me share some ideas that I've had from checking into this.

Like I said, I diagnosed the park interlock using a multimeter and the checklist in the factory service manual. At one point, none of the available answers to a test matched what I was seeing, so I didn't get a definite diagnosis. But, I noticed that when I tested the park interlock circuit, the O/D light came on!

So, suspecting the problems are related, I did the diagnosis for the O/D light and switch. That one indicated "Replace Instrument Interface Module". The IIM is basically a circuit board with a 16-pin connector running to it. Both the park interlock and O/D switch circuits run through it, so I am planning to replace mine and hoping it will fix both problems.

And get this - the following circuits all run through the IIM:

• O/D switch input
• O/D on/off indicator lamp output
• park interlock switch input/output
• Stoplight switch input (brake lights)
• coolant level switch input
• coolant level indicator lamp output

Many things sound familiar from your list of symptoms: O/D, coolant light, park interlock, and the relationship with tapping the brakes. So I would not be surprised if you had a bad IIM as well.

Note that there is still some speculation involved in this theory, and I don't know of a good way to test the module itself. It's about a $60 part, part number F5RZ-10E850-A. Unfortunately most places will not accept returns on electric components, so it would be nice to be more certain before buying a replacement. The only thing I can suggest is popping one out of somebody else's car and trying it in yours. It is fairly easy, about 10-15 minutes job, let me know if you need details, and please tell me the results if you get a chance to check it out.

Scott,

There is a Service Bulletin out by Ford for 95- 2000 Contours. If needed all wiring under the hood will be replaced free of charge if the wiring is bad (insulation falling off, etc) This warranty is for 10 years or 100,000 miles whichever occurs first. Since you are just slighly over 100k I run to your Ford Dealer to see what they can do for you. I had similar problems with my car 95 Contour and just had the wiring replaced. My car is now again reliable and has no electrical problems.
My mileage was 114,000. I worked out a deal with Ford and payed 20% of the cost of the wiring - came out about $120.00.

Ford gets 5 stars in my book!

Scott, to follow up on my earlier post...

I have replaced my instrument interface module, and it fixed the O/D switch but not the shift interlock. Probably that component wouldn't cause such wide-ranging problems such as yours, I would suggest getting the wiring harness checked as Bob Trautman has said.

Let us know what happens, and I am interested if you get any further info about your shift interlock also.

The loose terminal could very well be most if not all of your problems. When voltages get flakey, flakey things happen. Fix it first and then see if anything else is still acting up.

It is not a service bulletin, it is an Owner Notification Program, similar to a recall. It does not apply to all Contiques from 95 to 2000. IIRC it only applies to most 95 and 96 Contiques. If you think this could be part of the problem, have the dealer check OASIS to see if your car is involved.