Search Light Shuts Off

[jimshoen]

The search light on the top of the bus shuts off after about 40 seconds of operation.
Even though the light turns off the motor for rotation and tilt still operate. I have tracked the circuit and found the following item (see photo). It is about the size of a dime and yellow. When the system is off and cool the yellow item ohms out at 0.
When the power is turned on to the light the yellow item heats up and when it reaches 1.0 ohm the light shuts down.
The light on top of the bus is the second brand new one. The original that came on the bus had this same issue. Problem was squaked to (can't say) and they installed the first new one. The first new one had this same problem again.
The manufacturer of the light (Jabsco) sent me a new one this week because they said they were having problems with the unit. I put the second one on and guess what, no workie.
So I do not think the problem is in the light. Possibly I have too much resistance in the circuit, I do not know. I tested the power switch and it appears to be good.
There is a 10 Amp fuse on the hot line into the power switch and it is not blowing either.
Was' up?

[Petervs]

Jim,
It is a little hard to tell how that yellow thing is wired into the system from the pics.

But you can assume that when you turn on the light, power flows from the switch to the light on the roof through a main wire. If that wire is thin, there is a relay somewhere that sends the power to the lamp, if that wire is thick enough to handle the power fro the lamp it will be thicker than the wires used to control the up down right left motion.

Anyway, find the wire that feeds the lamp, then troubleshoot that wire. I am guessing the relay is faulty if there is one.

On my coach the same light has a failed right left drive gear. Would you like to sell your old one?

Peter

[jimshoen]

Peter,
When I get this figured out I will send you info on the one left over.

[jimshoen]

It is a PCP.....auto resetting current limiter. It will heat up if the circuit is pulling too much current and then shut off.

'The rest of the story...'
The wiring of the searchlight was wrong from the convertor 11 years ago. Three owners later and a bunch of head scratching and it is good to go.

Here is what happened.

The Jabsco Searchlight was modified by convertor to include a indicator light on the dash so that whenever the power is on to the unit the indicator light is lit.

Convertor mistakenly put the PCP in line on the hot (positive) lead to the light bulb. Then through the indicator light and on to the light on roof. The purpose of the PCP was to protect the indicator light not the Search Light bulb. The search light already has a 10 Amp in line fuse for protection.
The seachlight draws 50 watts and the PCP is good for a whole lot less than that. Maybe 5 watts. So as soon as the searchlight was turned on the PCP immediately began to overheat and would shut down in about 40 seconds.

The fix. Ran hot lead directly from switch to searchlight and tapped the PCP (dash indicator light) off the hot lead. Bingo everything works as designed. Just a minor screw up by the assembly crew 11 years ago.

Too bad it took me about 12 hours to research, investigate, and repair.
Good news was the actual repair took about 15 minutes.

[JIM CHALOUPKA]

Jim, the best news is that you figured it all out, and repaired it yourself!!

Kudos to you and thanks for the tale.

[jimshoen]

Peter here is the unit.

[jimshoen]

Jim thanks. As Jon has said, it is better just learn how to maintain these busses ourselves. I enjoy working on it, and get to buy more tools. Yes!

[Petervs]

Hi Jim

That left over unit is exactly like mine which is broken. Why not sell me that one?

Drop me an email at pvans@pacifier.com and we can work out the details. Thanks!