Fuses & Trailer Relays Help Needed...

[KC]

I have a '99 EB Explorer 4X4. I did not get a manual with it when I bought it so I'm running in the dark here!

My problem is that on my boat trailer, the running lights, headlights and left turn signal work fine. The brake lights and right turn signal do not work. This was verified with a tester plug connected to the 5-Flat connector. (5th wire connects to back-up lights for trailer surge brake lock-out). (EDIT) I forgot to add that all the lights on the X itself are operating properly!

I was able to find that fuse #7 on the interior fuse panel was blown (7.5A mini). I replaced it with another and it promptly popped as well.

Can someone tell me if that fuse is for my problem circuit and is there a relay that it powers that might be shorted? If so which relay and where is it located?

Again I don't have access to the owners manual and have not been able to find the info by searching!

Any help is appreciated!

Thanks!

 

[mikeh44]

does it pop with the trailer plugged in

 

[gijoecam]

Well, for starters, you've got two separate problems. Fuse #11 is for the Day/Night mirror/autolamp sensor, three legs of the instrument cluster, and the dimmer relay. Fuse 11 has nothing to do with the trailer tow connector.

The trailer left and right turn signals are fed through Fuse # 3 and 7 respectively (both 7.5A) in the fuse junction panel. Odds are you'll find #7 blown.

Now, if the left turn signal works, but the left brake light does not, you've probably got a ground issue. When the brake lights come on, do the running lights go out as well? (i.e. does the parking light stay lit until the turn/brake light comes on?) If, instead of going dim-bright-dim-bright, it goes dim-out-dim-out, that's usually a sign of a poor ground.

Now, the first thing to figure out is why you're not getting juice to the trailer plug. Start with the fuses and let us know what you find.

-Joe

 

[KC]

I'm SO confused now.... Last time we had the trailer hooked up the brakes and right turn didn't work. Running lights were good all around. I checked it with my test plug and found the problem as stated above (with noted exception of it was fuse #7, not fuse #11! So Mike, I will have to plug the trailer back in to see if that's what blows it. Today I didn't have the trailer plugged in - just the little test plug with LED's. After my searches I did find the fuse #7 popped. Figuring the trailer did it, I replaced it and checked it with the test plug again, at which time it popped as soon as I enabled the right turn signal.

So after reading the two replies I first noticed that yes it was in fact #7 fuse that was blown (THANK YOU GI JOE!). So I replaced it again, and tried all the circuits without anything connected and all went fine and the fuse remained intact. Then I connected the test plug and tried everything and it still worked!!! No blown fuse so I'm not sure what happened! Mind you this test plug is only 4 LED's, so it does not represent any kind of a load on the circuit so I will back it up to the trailer tomorrow and see if the trailer takes out the fuse again...

Thanks very much for the help, thats' why I love this site and contribute whenever I can.

BTW - anyone got a spare owners manual for this Explorer???

 

[KC]

The SAGA Continues...

OK, I did not have a chance to hook the trailer up to see if the fuse blows under a load today. However, my son ran to the store and told me he noticed the left turn signal indicator on the dash comes on when he pressed the brake pedal. I checked at the back and sho 'nuff, the left turn signal lamp lights up when he pushed on the brakes! No blinking, just steady.

Any ideas from the experts?

 

[KC]

Anyone???

 

[KC]

Bump... ???

 

[gijoecam]

I think you're dealing with two entirely separate and independent problems. Deal with one at a time. The left signal lighting when applying the brakes sounds like either a bad contact in the multifunction switch coming in when it shouldn't, or chafed wiring in the loom. That'll take some more troubleshooting.

-Joe

 

[KC]

Thanks for the reply Joe! The multifunction switch... that's the turn signal switch itself on the column, isn't it? How would one go about troubleshooting that? Do you know of a web page with the Explorer wiriing schematic, or can you suggest a book?

Thanks!