Headlights wont turn off - Relay good - 2000 Monaco Diplomat

[McDuugle]

Is it possible that there should be a relay that when : getting power to 86 (park break off) then creates then creates a connection between 87a and 30 - which would in turn turn on the headlight automatically?

[McDuugle]

Originally Posted by Dav L

Sounds like it's relay 48 on the schematic (F8).
If so the relay is correct and is wired:

86= high beam wire to coil
85 = DRL park brake to coil
87a = DRL to 25Amp fuse and normally closed. It should always be powered when ACC is On.
87 is ground and normally open
30 is low beam and common

Please post the sheet above (A1-H4) that all the wires connect to.

So, the Low beam would have power from 87a when the relay is deenergized.
It is energized by the High beam and the park brake. I assume the park brake switches to Ground at pin 85. Please verify with a multimeter.
when relay is energized, the Low beam is switched to ground.

85 and 86 are both ground they have continuity between each other.

[Ljwt330]

Originally Posted by McDuugle

85 and 86 are both ground they have continuity between each other.

No.



They have continuity between each other because they are at either end of an electromagnetic coil. When one end of the coil wire is grounded and the other end powered, electricity flows and an electromagnetic field is created. The two terminals must have continuity for the relay to work.



When connecting the relay to a device, one terminal must be connected to a power source and the other must be connected to a ground. It usually doesn't matter which terminal you connect to ground or power, unless the relay has a diode inside, which yours does not.

[Ljwt330]

Originally Posted by McDuugle

Is it possible that there should be a relay that when : getting power to 86 (park break off) then creates then creates a connection between 87a and 30 - which would in turn turn on the headlight automatically?

At this point, and from the diagram you linked, the issue seems to be that 87a has power when it should not. From your tests, 87a shows voltage all the time, but the diagram shows the voltage to 87a coming from the ACC relay. Period. There are no other wires between the fuse in the DRL wire and the relay in question.


What's strange is all other devices to the same ACC relay feed do not work with ACC OFF. So, what is feeding power to the DRL wire that connects to 87a? I can't tell from the diagram.

[McDuugle]

FROM THE MANUAL:
DRL system operates low headligt beam at reduced intensity when ignition key is turned on. With ignition on and paring brake applied low beams will turn off until park brake is released. When ignition key is turned off low beams will remain on for several minutes or until parking brake is applied.

[Ljwt330]

Originally Posted by McDuugle

FROM THE MANUAL:
DRL system operates low headligt beam at reduced intensity when ignition key is turned on. With ignition on and paring brake applied low beams will turn off until park brake is released. When ignition key is turned off low beams will remain on for several minutes or until parking brake is applied.

BINGO!


It seems you have a timed head light turn-off module somewhere that is either malfunctioning or you have not allowed enough time for it to de-activate the headlights. I suspect it's defective because the OP installed a manual cut-off switch.


With this information, it seems the relay is working properly.



After this last post, I went back and reread your OP. You mentioned that the high beams also do not work. Still, when you did your testing, you got voltage at 86 when the high beam switch was activated. This issue may be a fuse, another relay, or the filament in the headlight bulb if it's a single bulb system.


Looks like you may have a couple of tasks ahead. Find the module that controls the DRL shut-off, and trace the wiring for the high beams. I cannot read the wiring diagram in the link clearly when zooming in very close, so I cannot tell what is identified on the 87a wire where it connects to the ACC relay wire. The symbol is for a fuse, but there are also identifying letters next to it that may indicate it as the module that breaks the circuit after a few minutes. No other fuses along that track have those identifying letters.

[McDuugle]

86 gets power when the park break if off. Also can you send picture of where 87a connects to the ACC? I might be able to read it, just cant find it....

[Ljwt330]

Originally Posted by McDuugle

86 gets power when the park break if off. Also can you send picture of where 87a connects to the ACC? I might be able to read it, just cant find it....

I got the PDF from the link you posted, post #37


My understanding of your posts is that 86 got power from the high beam circuit, but only activated the relay when the parking brake was released, causing 85 to ground. I believe that is the case.

[McDuugle]

Originally Posted by Ljwt330

I got the PDF from the link you posted, post #37


My understanding of your posts is that 86 got power from the high beam circuit, but only activated the relay when the parking brake was released, causing 85 to ground. I believe that is the case.

My error. To clarify:
I cant get any power to 86 right now.
Only have constant power to 87a under all conditions.
And only get power to 85 when park brake is off.
When 87a and 30 close the circuit, headlights are on.

[JCM]

DLR means daytime running lights. They come on when you start the motor and are designed to help oncoming traffic see you. They are mandatory up here in Canada. They really do help me see oncoming traffic and help me judge the distance to them when passing or simply help me see the dull car on a rainy day and thereby possibly save a passing accident.
It is of interest that in 1980 we were required to turn on our landing lights 10 miles from a airport - to help be seen by other aircraft.

[mvadventure]

Originally Posted by McDuugle

Headlights wont turn off - Relay good - came with a by pass switch where the relay is, so I have to go outside to the bay and turn on headlights manually. High beams also do not work.

I bought a new relay and put it in but same story, headlights just stay on and do not turn off.

Any ideas?

Currently using battery disconnected to keep battery from draining when she sits....

Had this problem regularly several years ago with a few of my fleet of Ford E350’s. Solved it by replacing the headlight switch. Easy enough

[Rixthe1]

My best guess is you have 2 12v batteries wired in series instead of parallel. Old coaches have old wire, insulation gets rubbed through and can energize other wires. Find an old mechanic like me and pay to fix it right.

[Ljwt330]

Originally Posted by JCM

DLR means daytime running lights. They come on when you start the motor and are designed to help oncoming traffic see you. They are mandatory up here in Canada. They really do help me see oncoming traffic and help me judge the distance to them when passing or simply help me see the dull car on a rainy day and thereby possibly save a passing accident.
It is of interest that in 1980 we were required to turn on our landing lights 10 miles from a airport - to help be seen by other aircraft.

Originally Posted by mvadventure

Had this problem regularly several years ago with a few of my fleet of Ford E350’s. Solved it by replacing the headlight switch. Easy enough

Originally Posted by Rixthe1

My best guess is you have 2 12v batteries wired in series instead of parallel. Old coaches have old wire, insulation gets rubbed through and can energize other wires. Find an old mechanic like me and pay to fix it right.

It always pays to READ THE THREAD before posting. All the above comments have been addressed by either the OP or someone posting.


New and relevant insights are always welcome.

[FrankenRV]

I have a 2004 Scepter that had the same problem, but I resolved it by replacing the headlight switch. I have PDFs of the wiring diagrams for the 2004 Scepter/Imperial/Camelot and the 2005 Ambassador. They are pretty similar. But I can't upload here because the Scepter file is 7MB and the maximum upload size is 3MB. If you can send me your email address in a private message, I will email both wiring diagrams to you. The Ambassador file is 16.6MB.