Hello everyone! Could use your help in identifing the source of the problem.

I own '93 Explorer XLT, 4DR 4WD Automatic. Great car, especially for cold Russian winters, but it has one little problem.

Yesterday's evening I noticed that breaklamps don't work. Aha! Checked hazard lights, it didn't work too. Concluded that fuse #1 gone bad, it was correct.

After replacing the fuse, it blew after third pressing the break pedal. Hmm, looks like a short-curcuit somethere.

After short period of trying to find a complete list of symptoms, I found following:
1. Stop lights don't work
2. Fuse for breaklamps, hazards and cruise-control (#1) blowns after several times depressing the break pedal
3. Right turn light doesn't work. Turn signals relay clicks, but both right front and rear turn-lamps don't flash. Indicator lamp for right flasher doesn't light as well. Left turn-signal works OK.
4. After installing new fuse, all break lamps (including high mount stop lamp ) work for a minute. Then fuse blows.
5. Parklights and backup lights work OK.

I removed rear right stop/park light assembly. Using multimeter checked the bulbs and the assy for short-circuits. There were no shorts.

Then tried the right stop/turn/park light harness connector. Made sure the ignition is off, parklights is off too.

The connector has three contacts. Using ohmmeter, checked the resistance between contacts. Between 1-st and 2-nd contacts it was infinite, betwen 1-st and 3-rd it was less than 1 ohm.

That's all for now.

Could anyone confirm (or disprove) my conclusions? :
1. It is a short-circuit in wiring between rear right stop-light and multifunction switch

OR

2. Multifunction switch doesn't functioning properly.

Any feedback is greatly appreciated!

And, the most stupid question, I guess. But... Where to find the mentioned multifunction switch? And how does it look like?

My only source for such information, Chiltons guide doesn't provide such information. And here in Russia it's a hard task to find any good source for such info regarding US vehicles.

With many thanks in advance,
Yuri.

 

I am not sure, but there may be a plug on the firewall, or behind the driver's side kick panel, where you could un-plug the rear harness, and then ohm out the plug again. This way you could seperate the rear harness, and maybe narrow the problem down.

The multi-function switch is mounted in the steering column. It's the turnsignal, hazard and I think low/highbeam all rolled into one.

 

Thank you, Dave!

Now I have something to start with. If multifunction switch is located on/under steering column, it's obvious that plug should be somwhere near by. Since I know the colour code for the wires, it's easy to locate required connector.

Tomorrow (it's 1 am now at Moscow) I will try to follow your advice and test the wiring and the switch for short-circuits separately. I promice to report the progress. Though it could be relatively long process of finding the problem (Explorer is my second car, as a backup I use my wife's car).

Once again, thank you for advice!

With best regards,
Yuri,
Moscow, Russia

P.S. If I understand the purpose of multifunction switch correctly, it should perform algorythm of switching turn signals. In Europe, turn signals are separate lights. But on many US vehicles front turns are combined with front park lights, and rear turns connected to break lamps. So, to make this task possible, multifunction switch is used.

That's because you never find it in european car.

 

If anyone interested in solution of my problem, today I finally got it.

The cause was the multi-function switch. We replaced it, and the problem has gone. Also replaced rear light assembly (mine had a crack, and water could possibly damage the connectors).

So if break-lamps don't work, and replaced fuse blows again, it's wise to check this multi-function switch located inside the turn-signals/flash-to-pass/wiper control handle assembly.

Funny thing that blinkers worked (left worked OK and right worked sometimes).

With best regards,
Yuri,
Moscow, Russia
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93 Explorer XLT 4WD 4DR Auto