12 Volt Lights

[MadMax]

I have a 2008 Cougar 5er and have just discovered that the small light on the front (under the overhang) adjacent to the Docking Lights and Landing Gear switches is not working. The light on the roof of the front storage compartment is also not working. Both have serviceable bulbs and a voltage check of the sockets show 11.46 volts each (probably too low to activate the bulbs). The batteries (two 6V in series) show 12.96 volts total. I am currently plugged into 120 volts with my unit.
All other 12 volt bulbs in the trailer appear to be working (from the inverter I think).
Does anyone out there have any idea what might be wrong?

MadMax

[Ron]

The 11.6 volts will light the bulb and if you checked voltage in the socket, sounds like you have a grounding problem. Alot of times the outside lights with the rocker switch get corroded and over time they quite working.......

[MadMax]

Thanks Ron,
I'll check the ground again.
Madmax

[SteveC7010]

Originally Posted by Ron

The 11.6 volts will light the bulb and if you checked voltage in the socket, sounds like you have a grounding problem. Alot of times the outside lights with the rocker switch get corroded and over time they quite working.......

Agreed. The ground is your first suspect.

The switch and bulb socket are worth checking if ground seems OK.

FWIW, 11.6 vdc seems a tad low if the convertor is running. After you solve the problem with the lights, it's worth a look at the rest ov the system.

[ktmracer]

Originally Posted by MadMax

I have a 2008 Cougar 5er and have just discovered that the small light on the front (under the overhang) adjacent to the Docking Lights and Landing Gear switches is not working. The light on the roof of the front storage compartment is also not working. Both have serviceable bulbs and a voltage check of the sockets show 11.46 volts each (probably too low to activate the bulbs). The batteries (two 6V in series) show 12.96 volts total. I am currently plugged into 120 volts with my unit.
All other 12 volt bulbs in the trailer appear to be working (from the inverter I think).
Does anyone out there have any idea what might be wrong?

MadMax

I suspect you have a bad ground or power connection somewhere. 11.6V measured with a voltmeter which is very high impedance indicates even with very very low current draw your dropping 1V somewhere. With a bulb in the socket, if you could measure the voltage, It is probably in the 1V or lower range. If it was 11.6V with a good bulb, it would be plenty bright.

[MadMax]

Thank you all for your assistance. I believe the problem was a bad ground. Prior to my original post I had removed the negative lead from one of the batteries (in order to measure the battery voltage) and then after replacing the lead I did not check either of the two malfunctioning lights. Later when I did test the lights they came on bright and clear.
Thanks again.

MadMax