I installed a new 7 pin trailer connector on the coach. Every thing checked fine all lights worked worked great on the toad. My issue is now when driving the coach and using the turn signals, the coach engine looses power and starts missing, turning the turn signal off and the engine returned to normal. Is there and connection with trailer wiring to engine power? Have I wired something wrong? Help .
Terry
Thee should not be a connection to the engine with the trailer wires. This is one of those mystery problems that rear their ugly head and drive you crazy. I am going to take a wild guess that something is shorting voltage enough to cause the problem but how it makes just a miss without frying something is beyond me. Hope someone has had a similar problem.
Does the same problem happen without the toad connected?
You obviously have a short that "sucks" down the voltage to the point that the engine electronics don't have enough juice to function properly.
It may be you accidentally pulled a wire or tied into the always hot wire coming into the 7 pin connection.
Try verifying that you have the "hot" connection NOT connected in the male connector.
I think I may have this answer...
King throttle control is wired to rear brake light bulbs. King will limit throttle when it does not see a ground 'potential' on the brake light wire.
When the brake light switch is off, no voltage is on this wire. But the wire is still connected to the bulb, and this wire will be 'grounded' through the bulb filament.
Putting 12 volts on this wire tells King the brake pedal is pressed and what was previously a grounded wire is now a positive wire.
So I think King Control will go into limp mode if brake bulbs are missing or burned out and if the brake lights are on.
One gets around this with diodes and proper wiring.
Wow, Barry what made you think of that. I was starting to think it was the blinker fluid was low.
Phred,
Do you use synthetic blinker fluid
or the older kind????
Carter-
Wow holy smoke, does the king throttle go into limp mode, if a single brake light bulb fails? Maybe I missed something? I suck somewhat when it comes to DC & AC electrical Gremlins. I understand series safety circuits, parallel circuits, paths of least resistance, diodes and resistance, amps and voltage drops. First check on a DC dyestme
Phred,
Not if a single brake light filament fails (opens), but if the KING Controls throttle control board circuit path to ground through all brake light filaments open (doesn't matter how or where), then limp mode is imposed. BTDT. At least that is the way a '98 U270 works. Just means that one needs to keep the connection clean and preserved with CorrosionX and put in a new load of lamps when any single filament burns out.
HTH,
Neal
Neal, what about switching bulbs to LEDs? No burned out bulb problems. Would it work?
Our '89 coach obviously doesn't have the King problem.
Niitehawk,
I never tried it but I would anticipate that LED's, being diodes, would create a problem if the center and both side brake lights were changed to LED's. Easy enough to overcome though -- just put in a fixed resistor path to ground to simulate the three original filaments. Discussed with Rance once and he agreed.
Neal
Neal mentioned a potential LED problem. We are all LED on the rear lights, but a while ago I added a regular brake light bulb that is mounted on the front of the bed, so I can be aware while driving that brake lights are on. I did it to be aware of a 'sticking' brake light switch causing reduced throttle control. So I don't know if all LED brake lights will be a problem for King, as we still have a single incandescent bulb in the brake light circuit.
Barry,
What happens if you take out that extra bulb for a system test drive?
I do like the idea of a brake light that you can see!
I am not sure about what happens with inside bulb removed, but will try some day, but it will not be for a while.
But I do know our RPM will be limited if the brake wire is disconnected and the inside bulb is removed.
We put an emergency bypass switch on the brake light wire to temporarily disconnect King from the brake light circuit. One of the other reasons for the inside brake bulb was to present a ground to King throttle control when the emergency switch is activated, so we can still drive normally with a failed-closed brake light switch.
And when I removed the bulb with the emergency switch active, King did not see the ground, and a full throttle seemed to be limited to about 1,500-1,700 RPM.
BUT we are aware it is very important to not use Cruise Control if driving in this emergency bypass mode, as brake pedal will not turn off cruise control.
Safety is the ONLY reason King throttle / cruise control cares about brake light circuit. When cruise is engaged, King must release throttle when brakes are applied. So if it cannot 'see' brake bulbs, King assumes it will not see the brake being applied and keeps throttle from fully functioning.
Sounds like the original post combined turn and brake circuits, and when turn is active, the brake circuit is also on, telling King the brake pedal is being applied while throttle is being pressed.
I found the problem. I had connected the brake light to the turn signal. I removed it and connected it to the tail light. The engine does not miss anymore when I use the turn signal. Dumb mistake on my part. Easy fix when you know how to do it.
Cheers,
Terry