1994 Class A chassis electrical issue

[Rhianntp]

Hi, I hope someone can help

We have a 94 Damon intruder 345b motor home on Chevy 454 chassis. While installing a backup camera I tied the negative wire from the camera to the neg wire of the 3rd brake light and ran the positive wire from camera tot he positive wire on the license plate light. The idea I thought was i could runt he camera whenever i have the lights on. Everything seemed to work and then when we left on a trip while backing up the camera suddenly shut off and I apparently lost the running lights and brake lights function. I guess it was a bad idea to connect the wires in that manner?

Did it blow a fuse? I can only seem to find two fuse blocks, both to the left of the pedals under the dash... what looks like a normal auto fuse block and a smaller one nearby. All of those fuses seem ok.



I have since disconnected the camera, but now the tail lights, running lights, and brake lights no longer work. The hazard flashers make them all flash. The turn signal lights work only when not pressing the brake pedal.



Anyone have any ideas? Thanks !

 

[izifaddag]

First things first.
Insert thru the plastic the sharp point of a multimeter probe. Make sure you have voltage to the light.
If there is no voltage then step backwards. It probably is a fuse however if it was me I would be wanting to look at a wiring diagram.
Also both on semi trucks and class A campers they love to hide fuse panels. Quite possibly you have a surprise fusebox somewhere.
Have you tried disconnecting the camera and seeing if the voltage pops up?
There are 2 reasons a voltage disappears. It is either not reaching the destination or it is being pulled down.
There is also substitution. Use a 12v source and connect with an alligator clip to the light. If everything springs to life then you have lost the source.

 

[bullfrog]

You said you had flashers until you pressed the brake petal. It may be that you simply had a dual element bulb (1157? brake/tail) burn or vibrate the element enough it fell on the other element inside the bulb. Remove all the dual element bulbs front and rear and see if the license plate light comes on as it should, then start replacing the dual element bulbs (I would just put new ones in). Wear a thick leather glove while replacing bulbs as the glass gets really brittle over time and will really cause a nasty cut if it breaks while removing it, don't ask me how I know.

 

[Rhianntp]

First things first.
Insert thru the plastic the sharp point of a multimeter probe. Make sure you have voltage to the light.
If there is no voltage then step backwards. It probably is a fuse however if it was me I would be wanting to look at a wiring diagram.
Also both on semi trucks and class A campers they love to hide fuse panels. Quite possibly you have a surprise fusebox somewhere.
Have you tried disconnecting the camera and seeing if the voltage pops up?
There are 2 reasons a voltage disappears. It is either not reaching the destination or it is being pulled down. 
There is also substitution. Use a 12v source and connect with an alligator clip to the light. If everything springs to life then you have lost the source.

Shouldn't the bulb and wire be working if they flash when the hazard switch is on?  Turn signal works as well, but stops working if I press the brake.

 

[Rhianntp]

You said you had flashers until you pressed the brake petal. It may be that you simply had a dual element bulb (1157? brake/tail) burn or vibrate the element enough it fell on the other element inside the bulb. Remove all the dual element bulbs front and rear and see if the license plate light comes on as it should, then start replacing the dual element bulbs (I would just put new ones in). Wear a thick leather glove while replacing bulbs as the glass gets really brittle over time and will really cause a nasty cut if it breaks while removing it, don't ask me how I know.

I looked at all those bulbs and they seem fine. Seems suspicious to me that this happened after going in reverse and braking a few times. Suddenly the camera I wired went dead and all these issues started. I disconnected the camera, but that didn't help.  Did the negative wire from the camera being hooked up to a different circuit than the positive wire cause this or doesn't that matter?

 

[gsfish]

I've had tail lights do crazy things before that turned out to be caused by a bad ground. Do you have a multimeter?

Guy

 

[Rhianntp]

I've had tail lights do crazy things before that turned out to be caused by a bad ground. Do you have a multimeter?

Guy

Yea I have a meter

 

[bullfrog]

The fact the hazards quit working when you press the brake petal indicates the hazards are grounding through the brake light instead of where they should. When you press the brake petal you are taking away the ground. Are your hazards a separate single element bulb ( usually yellow) or are they combined with the brake light at the rear?

 

[Rhianntp]

The fact the hazards quit working when you press the brake petal indicates the hazards are grounding through the brake light instead of where they should. When you press the brake petal you are taking away the ground. Are your hazards a separate single element bulb ( usually yellow) or are they combined with the brake light at the rear?

The hazards function as they should.. its the turn signals that stop working when the brake is pressed... and at the same time there are no brake lights or tail / running lights at any time.

 

[bullfrog]

Did you pull out all the bulbs front and rear and check to see if there was power to the license plate blub? If there is install the bulb, it should light, if it doesn't check the ground, if it does start putting bulbs back in one at a time starting with the single element bulbs and each time seeing if they light as they should. If one is extremely dim It is probably a bad connection or most likely a ground. As I said before I would put in new bulbs especially the dual element ones as they fail and short out more often than you would think. Pressing the brake petal should only affect the tail lights if there is a bad ground (bad bulb socket could as well) or shorted bulb. The fact the lights light up at all indicates they are getting power and the fuses are good, that only leaves the above. The turn signal and brake light are the same element in a dual element bulb normally, the other element is the tail light.

 

[Rhianntp]

I will try all of that today.. thanks

 

[Rhianntp]

Did you pull out all the bulbs front and rear and check to see if there was power to the license plate blub? If there is install the bulb, it should light, if it doesn't check the ground, if it does start putting bulbs back in one at a time starting with the single element bulbs and each time seeing if they light as they should. If one is extremely dim It is probably a bad connection or most likely a ground. As I said before I would put in new bulbs especially the dual element ones as they fail and short out more often than you would think. Pressing the brake petal should only affect the tail lights if there is a bad ground (bad bulb socket could as well) or shorted bulb. The fact the lights light up at all indicates they are getting power and the fuses are good, that only leaves the above. The turn signal and brake light are the same element in a dual element bulb normally, the other element is the tail light.

All the bulbs back there and grounds seem ok....some details: With the parking/headlights only on the front running lights work... the rear and side markers do not....With a turn signal only on front and rear turn lights work....with the Hazards only on everything flashes as normal....Brake lights do not light up in any situation. Now, If I have the turn signal running and hit the brake.. they shut off... If i have the turn signal running and put the parking/headlights on the signal stops...

Everything worked fine until I hooked up that camera in the manner I described... then the first time I went in reverse with the lights/camera on and hit the brake a time or two then all of this began... to me a random bulb or bad ground would be pretty unlikely since it all worked before the above situation. This is why i think fuse somewhere or I damaged one of the switches that controls brake lights by wiring things how I did. I double checked every fuse I can find and re seated them ..all good..re seated all the bulbs.  So depressing not being able to know how to diagnose what switch or fuse might be bad.. I cant even find any fuses at all other than the normal auto block to the left of the steering column :huh:

 

[kklowell]

I went back and read your first post... it doesn't seem like you had the camera wired to turn on in reverse, but rather just when the lights were on, or did I miss something?

 

[Rhianntp]

I went back and read your first post... it doesn't seem like you had the camera wired to turn on in reverse, but rather just when the lights were on, or did I miss something?

That's right .. I connected the neg camera wire to the neg of the 3rd brake light.. and the pos of the camera to the license plate light... it worked... until the first time I hit the brakes a couple times

 

[bullfrog]

When you had all the light bulbs out front and back was the 12 volt power to the license plate bulb socket with the parking lights on?

 

[Rhianntp]

Here are the only other candidates for fuse blocks I can find anywhere else:

One is looking behind the cluster .. that black box with 3 screws on it against the firewall

The other is inside engine "hood" above the radiator area .. i think thats the computer though?

 

[Rhianntp]

When you had all the light bulbs out front and back was the 12 volt power to the license plate bulb socket with the parking lights on?

The license plate light never lights up now in any circumstance similar to the side markers and rear running lights, but at least those flash on hazard... perhaps the license plate light doesn't participate in hazard flashes?

 

[kklowell]

It seems to me, though I don't know and am not an automotive electrician, that the only thing all those lights have in common is a ground. They are not on the same circuit or they would all light up whenever you turned the lights on or pressed the brake pedal. Is that camper a fiberglass body? I also think there's another fuse box. They're common under the hood as well as inside the vehicle because there are so many circuits in modern vehicles.

 

[Rhianntp]

It's fiberglass body yes. There are lots of grounds attached tot he proper frame of the vehicle as well as the frameworks supporting the fiberglass. I really doubt a bad ground is magically going to appear coincidentally after I wire in a camera in a goofy manner. The other thing they have in common  are the switches that control them... like brake pedal switch controlling same bulb as turn signal switch, etc. Is it possible one of those switches was damage by my wiring job? Perhaps its a fuse that I can't find ?

 

[Rhianntp]

Thanks everyone for working with me on this problem I really would like to drive with brake lights. I can handle no running lights if I just never drive after dark. I suspect fixing one fixes the other in this instance though.