strobe system puzzler

I have the Whelen HDACF strobe system in my -7 that has worked flawlessly for over 300 hours since 2008 until this month where one day none of the strobes worked. I checked the switch and the fuse and that I had 12V at the power connector to the power supply and all were fine. Supposedly the power supply makes a noise when powered up and mine was silent. A friendly RV'er sent me an old ebay unit and it did not work either or make a sound.
I bit the bullet and ordered a new power supply which I receeived and decided that I would first plug the power supply into the harness before mounting it to check that it worked, powered it up and had three working strobe lights and everything looked good.
I then disconnected the power supply and mounted it (Vans mount behind the baggage compartment) then reconnected the cables and turned the system on and nothing, no power supply noise, no strobe lights, nada.
Removed the unit, rechecked 12V power available, checked ground continuity, and tried the strobes one at a time with no effect. I then connected the unit directly to the battery to make sure power and ground were good, still no sound from power supply.
Does anyone have any idea what could be the problem, the whelen tech said that an output short would cause the power supply to shut down but when I first tried the unit all the strobes appeared to be working.
I can sent the unit back under warranty but would like to make sure I have checked anything that might solve the problem rather than have another round of the power supply not working or only working for a few minutes, if there is an output short does it blow a fuse inside the power supply or is it a soft fuse that resets?
Appreciate any suggestions.

uk_figs said:

I then connected the unit directly to the battery to make sure power and ground were good, still no sound from power supply.

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Did you connect directly to the battery via the existing 12v wire, or with a different wire directly to the battery? I ask because I had what sounds like a similar issue, 12v measured at the power supply wire, but no strobes. Tracked the problem to a barely hanging on butt splice in the 12v wire, too much resistance with load. New wire fixed it right up.

-jon

Some power supplies won't fire with slightly low battery voltage. Try it again with a charger hooked to the battery.

Let me know

I have an extra Nova unit that was in my plane for 1100 hours. Just switch over to the Whelen LED system so its your if you want it. I'll bring it to Petit Jean if your going this year.

Gary

Will be at petit jean

Gary
Will see you there, bring pictures of the highlander

Respnse to comments

In response to the comments:
1. Connected direct to the battery with new connector
2. Will try with battery hooked to charger, but not sure that would explain the initial working then quitting after install

Voltage and current

I would suggest you check for 12v at the strobe power terminals with a load connected.
Volt meters draw almost zero current and can take you down the wrong path. Try connecting a head light or other simple suitable load across the voltmeter leads. Only with a load can you know that the system can supply the power (power = volts*current) needed to run the strobe.

If you have less than 12v with this test, you know you have a high impedance somewhere in the chain (switch, fuse, terminal, splice, frayed wire, etc)

Whelen strobes

I kinda agree with the Whelen Rep..... I don't how many times I've found intermittent shorts in one of the strobe output harnesses, or one of the strobe bulbs..Worth checking. Try disconnecting one strobe at a time (at the power supply) and then see if the other two work, if not reconnect and try another.... There is no fuse, that I know of, in the pwr supply, it's just built to shut off if it senses a short on the outputs. Good Luck

Status Update

After trying multiple troubleshooting steps I could not get the strobes to work, the only step I did not do was to hook the power supply directly to a battery with a load/strobe attached.
Sent the new power supply back to Whelen who just reported no fault found and the supply has worked flawlessly for the last couple of hours. So now I figure I probably have a good old power supply, a good power supply from my buddy Gary, and a good new power supply I also got frustrated enough to say scr*w this and ordered the LED replacement system from Kahuna based on what I saw at the Pine Bluff clinic and read here.

I am now determined to find out what the problem is and the next step is to take one of the strobes off and connect it directly to the power supply and connect the power supply directly to the battery. This should X out the switch, ground, wing wiring etc and get back to basics. Once I know the strobe, PS etc is good I can feed in the switch/fuse and the ground and then strobe by strobe.

End result though is that I will probably have a Whelen power supply and strobes for sale at a good price as I think I will install the LED system. anyway.

If this ends up like my Jeep Wrangler rear window wiper problem after spending a $1000 it will be a $15 bloody switch that is the problem

Still it keeps the mind active which at my age is a useful exercise

Problem area found

JD hit the nail on the head, I connected a 12V power supply directly to the strobe power supply and everything worked, power from the strobe switch still showed 12V with a voltmeter but the strobes did not work. Connected the power supply to the wire from the switch output side to the strobe power pack and everything worked so the problem seems to be with the switch

Not sure how to test the switch as in my tests it seemed to work a couple of times which led me down the wrong path.

I now have a new whelen HDACF power supply for sale @ $400 shipping included in the US.

power from the strobe switch still showed 12V with a voltmeter but the strobes did not work.

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The best way to troubleshoot an electrical circuit is while it is under load. Without a load, a digital voltmeter can indicate normal voltage even though there is high resistance in the circuit, i.e. due to a bad switch or connection. If it is not desirable to turn on the normal load, an automotive lamp can be temporarily substituted for the load.

Problem solved

After some more head scratching (it was NOT the switch) we finally found the problem:

After tracing the problem back to the fuse panel (use the B&C blade fuse block) we found that putting 12v to the wire directly to the strobes would not fire up the strobes even though 12v was showing and under load the voltage dropped to 3v. After some head scratching I pulled the wire off the fuse block and noticed that the spade connector plastic which is normally blue looked black :


I replaced the connector and everything started working fine, however I would like the electrical experts to tell me what might have caused this, as it looks like the connector has been getting hot and burnt or overheated the plastic cover. The crimp looks fine and the wire is fully inside the connector and the wire is the correct gauge for the current draw.
The system has been operating for a little over 300 hours.

The damage was caused by a bad connection, either between the male and female terminals, or between the wire and the female terminal (poor crimp). Bad connections mean high resistance. When electrical current flows through resistance, heat is generated. The heat causes more corrosion and more resistance which causes even more heat and etc. PVC insulation will smoke when very hot. Tefzel insulation can withstand much higher temperatures.

Same thing I had

uk_figs said:

After some more head scratching (it was NOT the switch) we finally found the problem:

After tracing the problem back to the fuse panel (use the B&C blade fuse block) we found that putting 12v to the wire directly to the strobes would not fire up the strobes even though 12v was showing and under load the voltage dropped to 3v. After some head scratching I pulled the wire off the fuse block and noticed that the spade connector plastic which is normally blue looked black :

I replaced the connector and everything started working fine, however I would like the electrical experts to tell me what might have caused this, as it looks like the connector has been getting hot and burnt or overheated the plastic cover. The crimp looks fine and the wire is fully inside the connector and the wire is the correct gauge for the current draw.
The system has been operating for a little over 300 hours.

Click to expand...

Hi Figs,

This is the exact failure mode I experienced with my Whelen strobes that I was trying to explain to you at Pettit Jean. I had the the same thing happen only it was a spade connector at the switch. It is my understanding, (definitely no electrical expert) that there can be quite a bit of resistance built up here which causes a hot spot. Some have told me that a poor crimp on the connector was the problem. I test pulled my connections but I chalked it up to one I must have somehow missed. We are not the only ones who have experienced this.

BTW, your Hatz project has competition.

Joe