In a couple of days is there anyone out there willing to help me troubleshoot some weird wiring on my cruise control, led tail lights, compartment lights, etc.?

At this moment I have disconnected my continuous duty solenoid from batteries to replace. trying to determine what size original was. No numbers on it.

I would text issues & pics as pics via b'mobile are difficult.

1)Tail lights are led-They work but are affected by the cruise set up I think. Maybe need a resistor. ???
2) cruise control off/on is wired to the compartment light switch on the dash board which connects to a relay in a compartment which is connected to the left turn signal which is connected to the rear brake lights somehow. The original owner could not figure out where the brake switch was so found a different way to operate it.
2a)Connect the cruise control correctly
to the brake switch. Which means the left turn
signal, compartment lights who knows what else will
have to be wired correctly etc.
3)I would like to set up the compartment lights to operate only the compartment lights & maybe go to led?

I think if I connect cruise control correctly that I will eliminate some issues. Or will probably create some too.

Thanks, Tere

Original. Cruise is connected to brake, not turn signal. Original was a bulb with a filament. With no power to it, it was a dead short. Put power to it and resistance get very high. So the bulb was the ground, push the brake and you loose ground. With LED you don't get that high resistance to shut off the cruise.

Replace the LEDs and problem may go away.

correct-Correct set up.

Original owner wired in cruise control at some time. states he could not find the brake "switch" to connect the wire to so he finagled the setup that is in this coach.

I don't know if Marvin & Doris ever used it.

The previous owner Jerry said he was never able to get it to work.

It is working but you have to know what to do to make it work. Jerry had rv for several years & replaced the regular tail lights with the led's in the last couple of years.

In other words from 1988 to 2016 it had the standard lights with the cockamamy wiring set up the way original owner had set it up. I want to set it up correctly. Which means i have to undo what has been done then put back together again correctly. Plus make sure all the other stuff works after I start disconnecting.

If I can, I want to keep the rear tail lights led. How can I do that? $400+ of lights & much labor as there was painting, diamond plate, rivets etc.

The cruise on my vehicle IS connected to left turn signal. It is used as the brake is used in normal set up. To disengage cruise on regular set up you press the brake... On my set up you engage the left turn signal.

I'm hoping to correct this. That among other issues are what I need help with. Or maybe we are saying the same thing. It may be simple for you but I need the big red crayon explanation. That is why I need help, for you simple, for me not so much.

To make my cruise work:
1) turn on compartment lights (1 1056 bulb in each compartment)at dash(all comp. lights in storage compartments remain on while using cruise)
2) slide cruise toward steering column on left turn signal to turn on
Drive-at 65mph slide control on left turn signal post to "set", & wait for cruise to engage(about 8mp slower than you set it at)Now you are cruising at about 55-58mph

issue- You are now riding up on someone slower than you & you have a car coming up so you can't move into the left lane with cruise on

I would normally just press my brake to disengage cruise or hit coast. On my set up you engage the left turn signal & the cruise is disengaged & you slow down, the car on your left passes, you slide the control toward the steering column again to reengage cruise & go around slow driver.

& so on.

Jim,Tere sounds very dangerous I have no idea how to help you , but I do hope you can get the correct set-up back!!

Sent you P.M
Doorman.

Ah, the magic of electrons...

There are many people who do not understand them. Strangely, some of them still try to do electrical work. Some of the worst jobs I have encountered have been those where someone made changes to (fix) an electrical system without knowing why.

Because they didn't know what they were doing, there is often no logical way to "undo" their work. I once spent hours tracing 3 wires. All 3 started at the same connection, then ran very different routes to end up at the same connection at the other end! Any one wire would have connected the dots.... the others were spares? I assumed they must feed something else and looked to find it. Nope.

Bottom line: If you can, remove all non OEM wires. Reconnect as many OEM wires as possible. When in doubt, run a new wire and abandon the old.

I will try to make sense of brakes and cruise control.
(Hang on, here we go!)

As for brake lights, they are powered right from the main fuse panel. A power wire runs from the fuse panel to one lead of two on the brake light switch. The other lead is attached via long wires to the brake bulbs in the tail lights. When the brake pedal is pressed the switch turns on power to the brake bulbs.

If your lighting system has separate brake and turn bulbs (ie amber turn signals) this is the end of it.

If your system shares the bulb for both brake and turn, it gets more complicated. The tail light bulbs can be powered from the brake system (both together) or individually via the turn signal switch and flasher.

When not turning, the turn signal switch sends brake power through and out to both rear bulbs. When turning, the turn signal switch supplies power, via the flasher, only to the one side. If both brakes and turns are used at the same time, the turn signal switch isolates the turn side through the flasher and allows the other brake light to light.

You did not specify the type of cruise, so the following comments are general in nature:

Most cruise controls have similar wiring functions. Usually have a fused power wire, ground wire, speed sense wire, brake sense wire, and some additional wires for the on/off and set/accel control switches. With power wire and ground connected, the speed sense wire is connected to some speed signal source, ie ignition system, transmission sensor, or other.

The brake sense wire is connected to the brake light (load) side of the brake switch. This brake light wire is indirectly connected to ground via the wiring harness and through the bulb filaments to ground. With no brakes applied this wire is grounded at 0V. If the cruise does not see a 0V ground connection, it assumes the brake system/wiring is not working and the cruise will not engage.

Meanwhile, when the brakes are applied, power is sent through the switch and the lights turn on. The brake sense wire now sends 12V to the cruise control, signaling to release the cruise control.

Soooo, getting to your problem... finally.

First, based on your description I have no idea what the PO did to get it to work the way it does and it appears he had little idea what he was doing....

I would locate and disconnect all cruise control wires. Reconnect any OEM wire that looks like it was disconnected. Hopefully the original lights, etc go back to normal. If not, fix them first.

The power source for the cruise should be a fused circuit switched by the key switch. (not the light switch?) Often you can find a spare location in the fuse panel, just be sure it goes on and off with the the switch.

I am surprised the PO could not find the brake switch. If you follow the brake pedal way up towards the top, you will see it up near the top. There is a power wire (orange, I think) on one side, 12V all the time. The other side is the brake light wire. This is where the cruise control sense wire should be tied to. (not the left turn signal?)

As we have seen, the use of LED brake lights confuses the cruise control. Since the LED lights are diodes, not filaments, they do not allow the cruise control to sense ground through them. The cruise control assumes the brake lights are not there and will not engage.

The fix is to attach a dummy light or other resistor to the tail light wiring. The cruise finds ground through it and will then engage.

Once engaged, the speed is determined by the speed input sensor wire signal. Depending on the particular cruise control, this signal may come from the ignition system, the transmission, or magnetic sensors on the driveshaft. Because these signals vary a lot, most cruise controls have an adjustment to fine tune the final road speed. This is often called the "zoom" or "set" function.

Check your cruise control for this adjustment. Note the speed when engaged and while engaged, adjust the zoom to match the set speed. You should be able to get within 1-2 mph on level road.

Good luck with your project.

Have Barth, will travel

has comp lights on for cruise turn on??? Just want the brain to burn more of those electrons. Tere just need to extend her left arm father out the window for changing lane. Tere has other issue she is working on before she gets back to this problem. but it is interesting.

The only lites I have changed to LEDs are the headlights. I do very little nite driving and I also have have a philosophy "if it's not broke, don't fix it".

You guys are awesome!!! Gary, Steve & Craig!! You too Kevin. Thank you for all of this great information. After doing a little bit more investigation, I believe the original owner Bill Brown knew more about electricity than meets the eye. The system he installed is the ACME CC & I do have the manual w/wiring diagram. Some notes from orig.owner BB of what was done & why & some testing numbers. In the end I may be installing the bulb for the ground issue all of you have been discussing. TBD

I am currently doing some plumbing. Should be finished with it today. I'm waiting on my new cd solenoid to replace the old one that I've removed. I disconnected the batteries & shore power to do this & will be able to reconnect after I install the new solenoid. It should be here tomorrow.

Once I reconnect the wiring & get electricity back to the system I will be able to test more of the cc system.

You will be hearing from me soon. Thanks again for all of your input. I know we will resolve these issues one way or another. Stay tuned.

Tere

I had problems with LEDs in the brake lights as well. Go back to incandescent unless you want to do alot of rewiring to make the LEDs work right. The way the bulbs are shared (as described above) between the brake and turn signals is a bit screwy. I would get continuity to ground in one function on one of the wires and it would be hot during a different function (turn signal) just for example. LEDs will only work in one direction (from my understanding). I guess that's how they did it in the 80s...

UPDATE

I disconnected the cruise control, the left turn signal wire & the compartment light that was wired to a relay in one of the compartments. Original owner wired it this way for some reason. To use cruise control you had to turn on compartment light switch on on dash in order to engage the cruise control. Which meant if driving at night & want to use cruise the rv compartment lights would be on while driving.

Per SteveVW I connected another ground wire to the already grounded tail lights. Now all of my lights to work correctly. Go figure.

Will reconnect cruise later. Main thing was to get the lights work properly.

Tere

Ingenious. When night driving you set the cruise to take care of something elsewhere in the coach. He should have wired in the water pump to flush the toilet. Forefather of Elon's.