BAC Forum
General Boards => Technical Support => Topic started by: Michael Hannan on December 26, 2015, 11:48:09 PM
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Hello. I have lost power to the driver's 12v outlet & Bay lights. I searched the forums for the fuse panel location but failed to find a fuse panel (at least something I'd recognize to be one) in the driver's side electrical bay. I checked the 12v panel in the bedroom but none of the breakers/fuses have tripped and none appear to control my problem systems. I checked under the dash driver's side but don't see anything there. Can anyone help please?
Thanks
MJ
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Look for a GFI?
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GFI is for 110 ac no?
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After searching I found a schematic of the driver side electrical bay. It shows amperage values on the terminals. Is there a replaceable fuse under each terminal? Is it a standard auto type fuse or something I probably haven't seen before.
Thanks
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Michael,
Those are circuit breakers, not fuses. To reset them, power needs to be removed and reapplied. I think the circuit that is impacting you is on the Batt. side, not the ignition side since teh 12v power outlet and bay lights normally work even when the ignition is off. I think that opening the chassis battery disconnect switch for a few seconds should reset the breaker, if that is what the problem is.
Steve
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Thanks Steve. I'll check it out tomorrow in the light of day.
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Michael and Steve,
I believe those breakers are thermal type which means they open with current flow that is too high based on the rating. Little silver rectangles under the copper busses on one end, with nutted terminals and the load connected by wire to the other lug. When you find the right breaker, there is no reset per say, if it is open it should reset itself unless it has fused open or just fell apart inside. Steve's method of resetting would work in that if the current load was too high, killing all the power allows it to cool, but cooling takes some time and it is not an electronic instant reset. If functional it would also reset itself as it cooled.
You can use an automotive resetable breaker with a button on it and a couple of wires to temporarily diagnose this or a fuse holder and some fuses. If there is no open or short in the circuit then a new breaker will fix this, if there is an open or short you can use the temporary breaker or fuse while diagnosing the problem. Hope this helps.
Later Ed
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Ed are the fuses underneath regular automotive style fuses?
Thanks
MJ
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Michael,
If you are asking about a temporary fuse to diagnose or by pass a bad thermal breaker, I was referring to a standard 12V plastic top color coded (for amps) fuse with two prongs. They are used in any modern car, come in several physical sizes, either would work along with an inline wire harness socket that you can get at any automotive store. It is a rubber socket, sometimes with a weather seal cap that can go down over the fuse and typically two red wires that come out of the rubber socket base. A 15 to 20 amp fuse would most likely work for a bypass to a faulty breaker as a temporary measure or for diagnostic use. The physically smaller size fuses may not go as high as 20 amps, not exactly sure where the cut off is.
I have a 2002 Marquis and I am assuming that your front panel below the drivers seat is similar to mine but I am not sure of that. If you want to post a fairly close up picture of a section of your copper busses and wiring I could tell if you have thermal breakers.
Later Ed
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I had trouble resizing the photo small enough to post.
MJ
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Mike,
What they are sharing with you is the circuit breakers are mounted horizontal behind the copper strips. Example is the strip on the left of your photo has 8 circuit breakers. The 12volt power source goes to the common copper strip. The load side (output) goes to each respective wire or circuit. A simple test light can check operation by attaching the test light to the ground bar and touching each output wire. Note, the circuit you are looking for is NOT on the ignition circuit which is only powered when the key is on. Hope this helps, Fred
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Thanks Fred. By common ground bar do you mean the two ground terminals to the right of the windshield washer reservoir?
MJ
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Mike,
Just below the 8 circuit breakers on the left of your photo is the ground bar strips. Didn't see the washer reservoir in your photo. Fred
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Mike,
What they are sharing with you is the circuit breakers are mounted horizontal behind the copper strips. Example is the strip on the left of your photo has 8 circuit breakers. The 12volt power source goes to the common copper strip. The load side (output) goes to each respective wire or circuit. A simple test light can check operation by attaching the test light to the ground bar and touching each output wire. Note, the circuit you are looking for is NOT on the ignition circuit which is only powered when the key is on. Hope this helps, Fred
Fred, just wanted to say thanks, that was the best description I've seen on the CBs. I have heard of them since I bought the coach. I thought that maybe I had fuses somewhere because I didn't recognize, until now, what they were. Again, thanks.
Jerry
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Hello. It has been awhile since I first started this thread. A lot has happened that caused me to put this off until today. So this what has happened.
I removed the porch lightbulb to see if it was good. It appeared as though the filament was still intact and a did a continuity test from wire to contact and it Ohm'ed out showing a connection.
Today I used the meter to check for voltage at the terminals on TB1 that are connected to the porch light. Bothe showed a very small reading while the light switch was both off & on. However, when I went back into the coach, the step light that had also not been working was now working. So I shut the switch off and replaced the porch lightbulb. Now neither the porch light nor the step light are working. So I'm stumped.
Any ideas?
MJ
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MJ,
A number of things could be going on.
If you haven't already, replace the porch light bulb with a new one. The filament could show continuity but still have a path to bulb ground.
See if you have 12V on TB 1, 11 or 12 with the bulb removed. If not, the 12v source (to either TB 1, 11 or 12) is missing. One wire on TB1-11 goes to R14, pin 30. One wire on TB1-12 goes to R14 pin 87. Remove those 2 wires from the TB and see if you have 12v on either TB1-11 or 12. If you do, I suspect R14 is faulty. If not the source is bad and you'll have to trace the wire remaining on the TB.
Also, check that you have 12v at both terminals on CB12. It supplies 12v to the R14 coil.
Steve
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Thanks Steve. I'll pick up a new light bulb while on on the main island tomorrow. I already have a new relay if that's the problem.
MJ
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Well I did all that you suggested Steve and then some. I do have a porch light again but it's a workaround & not a fix. There isn't any power at TB1 11 or 12. I checked R14 anyway and it showed some heat discoloration on one of the terminals so I replaced the relay. Still nothing. I moved the TB1 11 & 12 wires to other terminals that had power. Still nothing. I checked the voltage coming into R14 and 3 showed 14+ volts and one showed 2.3. I checked the voltage at the switch for the light and it was good. There's a switch on the light itself that looked like it had seen better days. I cut it off and joined the wires and the light works. The light on the step still isn't but I suspect it needs a new bulb. So, I still don't know why there isn't power at TB 1 11&12 but for now I have light.
Thanks for your help Steve.
MJ
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MJ,
If you checked R14 prior to moving the wires on TB1 and found 12V on 3 of the 4 connections, something is mis-wired as you should have also found 12 V on one of the TB1 terminals, probably TB1-12. Attached is the wiring for R14. BTW, how many wires are on R14?
Steve
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I checked the voltage of the wires before attaching them to R14 but after moving TB1 11 &12. There are 4 connection to R14.I'll have to snip the wire ties and follow the wires from R14 to their source and compare to your schematic. So are both TB1 11 & 12 supposed to have voltage? I'm thinking yes but the switch between the two in the schematic has me confused. Not a difficult thing to do. LOL
MJ
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MJ,
One should have 12v all the time, TB1-12 I think. The other should get power when the light switch is on which triggers the relay's contacts (switch) to close and thus supplies voltage to the light.
Steve