Strange thing happening with headlights

[Joeycockerspani]

On my 2006 Forest River Charleston with a Freightliner chassis and 330 HP Cat engine, I recently had the inverter/charger replaced. The old one had gone on the fritz. As I was driving home I noticed something weird going on with the headlights. When I arrived I did some investigation.

As soon as you release the parking break the lights would come on, the blue high beam indicator on the dash would come on, and then the front headlights on either side would start turning on and off at random,out of sync with each other.

I spoke to Freightliner customer service and they said it was likely a headlight control module gone bad. That was easy enough. So I got the part number from them, ordered a replacement and installed it yesterday. All that did was is slightly change the nature of the problem. When the parking break is released, rather than the blue high beam indicator light coming on and staying on, now the indicator light methodically flashes on and off on the dash, and the headlights do a similar dance, but slightly different orchestration than before the module was replaced. Now the driver side headlights turn themselves on for 8.6 seconds then turn off for about 4 seconds. Then they do that again and again. The passenger side headlights turn themselves on and then off every 6.6 seconds. Each time the driver side lights are on when the passenger lights come on, there is short blink in headlight intensity.


If the parking break is on, the lights are off accordingly and nothing happens. But with the parking break off, if I turn on the lights with the switch, the same kind of light show starts up again. The light show is slightly different, but still a light show, if the parking break is off and the light switch is turned on.


None of this was happening before the inverter/charger was replaced. Nothing else about the inverter/charger seems to be irregular.


Does anyone have a clue as to what may being the cause of this really weird problem?

[Joeycockerspani]

rgatijnet1 wrote:
Look for the circuit breaker for your headlights. A lot of headlight systems have an automatic resetable circuit breaker so that you do not get stuck with lights out if a fuse blew. If they are blinking it probably indicates that there is a short somewhere in the circuit and the circuit breaker keeps popping off and on to protect the wiring and alerting you there is a short in the wiring.

Hmmm, that sounds reasonable. I'll call freightliner and ask them about a headlight circuit breaker. Thx

[dougrainer]

Go to either Headlamp and look at the wiring behind the frnt cap. FIND the heaviest White ground wire running to either head lamp. Run a 12 gauge WHITE wire from a good frame ground bolt and just splice this ground wire around that Headlamp ground. See if the problem goes away. If so, make this new ground wire and good splice. Doug

[wa8yxm]

time2roll wrote:
My first guess would be a bad ground. And since an inverter was recently installed I would check those ground connections first.

Second on that.. Bad ground... Modern headlight systems are a bit.. er... Different than what I would expect.. They do some strange things.

My "new" jeep even lets me know when BOB take up residence (Who's BOB.. Well since it's all caps clearly it is an acronym Burned Out Bulb)

I know a few BOBs.. one of 'em is even named Bob.. (but he does not hang out here so that's enough about him).

[time2roll]

My first guess would be a bad ground. And since an inverter was recently installed I would check those ground connections first.

[rgatijnet1]

Look for the circuit breaker for your headlights. A lot of headlight systems have an automatic resetable circuit breaker so that you do not get stuck with lights out if a fuse blew. If they are blinking it probably indicates that there is a short somewhere in the circuit and the circuit breaker keeps popping off and on to protect the wiring and alerting you there is a short in the wiring.