Lamp Outage Module?

[1996BLKBauer]

On my 1996 Eddie Bauer Explorer I have apparently been driving around without brake lights. I was diagnosing the truck the other day, I found that I got no power to both of the tail lights, but that the running lights did work. So since the CHMSL worked, I excluded the fuses, switch, and a majority of the wiring fro being the issue. I narrowed it down to the Lamp Outage module, which is found in my truck, because I have the Message Center, or a common splice that the lights share. I know where the LOM is, I have yet to take it out and inspect it, but just in case it is not the problem, where is the splice at for the rear brake lights?

Hopefully I can just solder the connection, and be good to go. BTW, I do not have a trailer harness hooked up, and the cap is on the end, so nobody has messed with it. If the module is in poor shape, and I have to buy a new one, does this require a trip to the stealership for the part, or is it offered in the aftermarket?

 

[bobflood]

I'm confused - tail lights working have almost nothing to do with brake lights working. The switch on the brake pedal is the first thing to check.

Does your high mounted brake light work??

And what is "CHMSL"?

 

[koda2000]

I'm confused - tail lights working have almost nothing to do with brake lights working. The switch on the brake pedal is the first thing to check.

Does your high mounted brake light work??

And what is "CHMSL"?

I'm guessing here, but...
CHMSL = Center High Mounted Stop Light

 

[bobflood]

I'm guessing here, but...
CHMSL = Center High Mounted Stop Light

Well, Duh!! on me!! Sounds like a good guess, koda!

If the CHMSL is working, then brake switch is working. However, the CHMSL has a separate fuse in interior fuse box after the brake switch, so the wiring is separate for that all the way to the back. According to the wiring diagram, the regular brake light wire is "light green" and goes thru the LOM (when equipped) on a single wire to a splice somewhere, where it splits off to the two brake light sides, and makes a connection to the Anti-Theft system. According to the diagrams:

- At the LOM, Pin 14 is the brake light "in" wire and Pin 15 is the "out" wire.

- The Anti-Theft connection is on Pin 29 of the RAP module.

If you can get at these connectors and test for power with the brake pedal applied, you can sectionalize the problem a little farther.

Re the splice: I suspect (but am not sure) it is in the wiring channel at the driver's side rear door, underneath the plate in the door sill. That is where the splices for the door lock relays are that are sometimes at fault when folks have those problems. Good luck.

 

[96eb96]

If the module is in poor shape, and I have to buy a new one, does this require a trip to the stealership for the part, or is it offered in the aftermarket?

I've fixed mine by soldering it. It is easy to take apart, but the broken solder isn't always that obvious. With a wiring diagram you can pinpoint the circuit that is giving you trouble, put a meter on the traces, wiggle the circuit and see the break. The usual failure point is the headlights, however. The OEM part is actually made in China.

Your other alternatives are some vendors selling NOS units - they are about $70-$80 bucks. I don't believe they are available at dealers anymore (they were removed from the trucks in 98 or 99 I believe). There is no aftermarket for this part, from the research I've done.

 

[1996BLKBauer]

Yea, CHMSL, is Center High Mount Stop Lamp. It does work, so the switch, and fuses are not the problem. I have been sort of busy so I have not gotten any further to figure this out. Now I have a question, if I where to just jump the wires as a test, would that be OK, or could I possible damage something? I do want to fix it correctly, but I NEED brake lights, so I could care less about some $70 module for now.

 

[deweyville65]

FWIW, and as for me being old school, wouldn't it be nice if we DIDN'T have so much wiring in these vehicles? I am tempted to remove ALL the wiring and just rewire with what is actually needed. For those who don't remember, back in the 60's we didn't have all these modules and relays to contend with. Ah, life was MUCH simpler back then. Just my thoughts.

 

[96eb96]

Yea, CHMSL, is Center High Mount Stop Lamp. It does work, so the switch, and fuses are not the problem. I have been sort of busy so I have not gotten any further to figure this out. Now I have a question, if I where to just jump the wires as a test, would that be OK, or could I possible damage something? I do want to fix it correctly, but I NEED brake lights, so I could care less about some $70 module for now.

The CHMSL is on a different circuit from the other brake lamps, but testing it just proves the switch is ok. I posted a wiring diagram I believe in one of your other threads.

You can definitely bypass the LOM module, It is an option that has even been eliminated from some cars with the message center. You will get a warning unless you can duplicate the voltage output from the LOM to the the appropriate pin on the computer (but it doesn't affect anything).
I don't suggest buying one until you are sure it is the problem.

Look at the diagram in this and the other thread, there is more than enough info there to do testing. You can disconnect the LOM connector and the socket on the lamp end and check the indicated circuits with an ohmmeter.
Also check for voltage at the LOM Brake input when you step on the brake..you get the idea.

Another possibility is failure of your light sockets. While both going at the same time is unlikely, they are a failure point and should be replaced (they are cheap). They do not show any signs of failure.

**oh, and does your alarm flash the rear lamps when you click it twice? I believe it should, because it is connected into that circuit!

 

[koda2000]

FWIW, and as for me being old school, wouldn't it be nice if we DIDN'T have so much wiring in these vehicles? I am tempted to remove ALL the wiring and just rewire with what is actually needed. For those who don't remember, back in the 60's we didn't have all these modules and relays to contend with. Ah, life was MUCH simpler back then. Just my thoughts.

i hear what you're saying. i think the reason i hoping to stick with my 2000/2001 vehicles is that new vehicles are too complicated to fix, with all their tech stuff, and it gets worse with each passing year. sometimes i read the new Explorer's Forum and the problems they report with electronics, MFT and Sync, same like a nightmare. then again it took me almost 10 years to track down and fix an occasional starting problem on my '61 T-Bird... that's 60year old wiring for ya, lol

 

[1996BLKBauer]

i hear what you're saying. i think the reason i hoping to stick with my 2000/2001 vehicles is that new vehicles are too complicated to fix, with all their tech stuff, and it gets worse with each passing year. sometimes i read the new Explorer's Forum and the problems they report with electronics, MFT and Sync, same like a nightmare. then again it took me almost 10 years to track down and fix an occasional starting problem on my '61 T-Bird... that's 60year old wiring for ya, lol

Well I believe that the LOM is for stupid people, I mean really, who cannot figure out if there brake lights, or headlight have gone out? For me a took a while, but I still noticed. In the 90's car manufacture only put wiring in vehicle to support the lights inside the vehicle it's self. If you want a Trailer or something like that, you will need a box that you will have to run a 12, or 10 gauge wire to, and the stock wiring acts as a switch for the trailer. It is really just to cut costs.

 

[1996BLKBauer]

The CHMSL is on a different circuit from the other brake lamps, but testing it just proves the switch is ok. I posted a wiring diagram I believe in one of your other threads.

You can definitely bypass the LOM module, It is an option that has even been eliminated from some cars with the message center. You will get a warning unless you can duplicate the voltage output from the LOM to the the appropriate pin on the computer (but it doesn't affect anything).
I don't suggest buying one until you are sure it is the problem.

Look at the diagram in this and the other thread, there is more than enough info there to do testing. You can disconnect the LOM connector and the socket on the lamp end and check the indicated circuits with an ohmmeter.
Also check for voltage at the LOM Brake input when you step on the brake..you get the idea.

Another possibility is failure of your light sockets. While both going at the same time is unlikely, they are a failure point and should be replaced (they are cheap). They do not show any signs of failure.

**oh, and does your alarm flash the rear lamps when you click it twice? I believe it should, because it is connected into that circuit!

I know the light sockets for my reverse light s are going out, some times they work, some times they do not. Also, none of my lights flash when the button is depressed twice. I did notice that somebody has run 2 wires from somewhere inside the truck to the headlights, not sure why though. I am afraid to see what I find. I am wondering if some body has already bypassed the LOM for the head lights. I have checked all the fuses, checked the switch, so everything upto the LOM, and or the spice is OK. I do understand that the CHMSL is on a different circuit, but the main fuse, and switch would have to be working, in order for that to work. Thanks for the diagram again.

 

[96eb96]

I know the light sockets for my reverse light s are going out, some times they work, some times they do not. Also, none of my lights flash when the button is depressed twice. I did notice that somebody has run 2 wires from somewhere inside the truck to the headlights, not sure why though. I am afraid to see what I find. I am wondering if some body has already bypassed the LOM for the head lights. I have checked all the fuses, checked the switch, so everything upto the LOM, and or the spice is OK. I do understand that the CHMSL is on a different circuit, but the main fuse, and switch would have to be working, in order for that to work. Thanks for the diagram again.

The headlight aux wiring is likely for additional lights on a brushguard.

Do you have the tow harness adapter?

Notice how the ground wire is common between the brake and stoplights. When you click your alarm the stop lights don't flash. That would kind of point me in that direction..just a thought.. Put a test light on one of the rear brake light hot wires and body ground - then step on the brake. Should be easy with the diagram

 

[1996BLKBauer]

The headlight aux wiring is likely for additional lights on a brushguard.

Do you have the tow harness adapter?

Notice how the ground wire is common between the brake and stoplights. When you click your alarm the stop lights don't flash. That would kind of point me in that direction..just a thought.. Put a test light on one of the rear brake light hot wires and body ground - then step on the brake. Should be easy with the diagram

I have already figured out that the ground is not a problem. the running lights work, which share the same ground, I also did a voltage drop between the battery ground and ground for the tail lights, and it had less than 1/100th of a volt drop. So the ground is in good shape. I do not have the adapter for the towing harness. but I do not have a tow hitch, and the cap is still on the adapter. So I believe it was never used.

 

[bobflood]

Yea, CHMSL, is Center High Mount Stop Lamp. It does work, so the switch, and fuses are not the problem. I have been sort of busy so I have not gotten any further to figure this out. Now I have a question, if I where to just jump the wires as a test, would that be OK, or could I possible damage something? I do want to fix it correctly, but I NEED brake lights, so I could care less about some $70 module for now.

Sure - just unplug the LOM and jumper Pins 14 and 15 together at the connector. Then step on the brake pedal and see if the brake lights work. Before you jumper it, you should verify that you have 12V on Pin 14 when the brake pedal is applied. Good luck.

 

[1996BLKBauer]

Sure - just unplug the LOM and jumper Pins 14 and 15 together at the connector. Then step on the brake pedal and see if the brake lights work. Before you jumper it, you should verify that you have 12V on Pin 14 when the brake pedal is applied. Good luck.

Thanks, I'll try that. probably not tomorrow though, because we are supposedly getting our first snow storm here in northern IL in something like 290 days. but soon.

 

[Kendahl]

Thanks for the epic thread! I found a broken solder joint on the LOM. Resoldered it and viola! We have brake lights. If it happens again I will just bypass it.

Thanks again.

 

[J_C]

You can definitely bypass the LOM module, It is an option that has even been eliminated from some cars with the message center. You will get a warning unless you can duplicate the voltage output from the LOM to the the appropriate pin on the computer (but it doesn't affect anything).

Old topic but still got a reply so I'll add.. I could be wrong but don't think that this is correct, as I reversed engineered one a few years back in a topic on this forum.

In order to set the message center warning it has to send a signal to the message center. If you disconnect the LOM so it can't send a signal, there should be no warning lights. If you jumper around the LOM for the power to the headlights/etc but leave the LOM connected, there would be, unless you cut some traces on it.

Here's the post I'm thinking of:

97 EB 'Check ALL Lamps' after LED switch

I replaced all my 1997 Explorer Eddie Bauer lighting with LED lights. Brake, tail, reverse, turn, interior and the headlights are now HID bi-xenon everything but the high mount 3rd brake light and instrument panel/dash is now LED. Prior to replacing the stock bulbs with these LED's I had no...

www.explorerforum.com

 

[96eb96]

Old topic but still got a reply so I'll add.. I could be wrong but don't think that this is correct, as I reversed engineered one a few years back in a topic on this forum.

In order to set the message center warning it has to send a signal to the message center. If you disconnect the LOM so it can't send a signal, there should be no warning lights. If you jumper around the LOM for the power to the headlights/etc but leave the LOM connected, there would be, unless you cut some traces on it.

Here's the post I'm thinking of:

97 EB 'Check ALL Lamps' after LED switch

I replaced all my 1997 Explorer Eddie Bauer lighting with LED lights. Brake, tail, reverse, turn, interior and the headlights are now HID bi-xenon everything but the high mount 3rd brake light and instrument panel/dash is now LED. Prior to replacing the stock bulbs with these LED's I had no...

www.explorerforum.com

Interesting. You know your electronics!

I know the LOM can fail in such a way where you can lose your tail lights and/or brake lights AND there is no indication to the message center. I had this. There is another module in the back that also uses the brake signal (I believe the security computer to lock the doors, could be wrong).

All my pins have a second path now, I am confident it will more than outlast the truck!