My Arrow's instrument panel light don't work

[maduro]

My instrument panel illumination lights never worked since I bought my arrow a year ago. I am now trying to sort it out. I've replaced all the old incandescent bulbs with red LED bulbs to no avail. None of the light bulb illuminate when I turn it on. I am now thinking the wiring is messed up. Where do I even begin to troubleshoot this issue if I can/able? Thanx.

This thread seams to touch on the subject but it's old. Wondering if there is a more updated solution.

Panel lights problem

Interesting (and annoying) electrical problem. Only appears to affect the panel lights (those little GE53 bulbs). Very few of the instruments in the cherokee are self-lit. Most have the GE53 bulb at the corner of the instrument, and the plastic panel overlay has a reflective surface on the back...

www.pilotsofamerica.com

 

[pburger]

What year Arrow? It's probably a fried transistor. The light dimming circuits varied over the years. Some had one transistor, and some had two. If there is a short in the light circuit it will fry a transistor. That's probably what happened. You need to first verify that there is no short to ground in the lights, and then once that has been checked (and corrected if necessary) you may need to replace a transistor.

 

[maduro]

Its a 73 Arrow ll. Where are the transistors? Thank you.

 

[3393RP]

Start here.

PA28-181 Panel light glitch

My 1980 PA28-181 has been having a slight glitch of the dash lights that are controlled by the vertical wheel rheostat on the right. Over the years it often would not come on immediately unless I recycled. Later, even after recycle, there would be a slight delay, and then suddenly come on...

www.pilotsofamerica.com

 

[Bell206]

I've replaced all the old incandescent bulbs with red LED bulbs to no avail.

FYI: You may want to take a few steps back. One, not all LEDs will work with conventional lighting systems. May want to have some one who understands the basics to perform some troubleshooting and start by putting all the correct bulbs back in before you potentially smoke your new bulbs. One very common fault with a conventional dimming instrument light system is a $2 transistor(s) fails or with older systems the rheostat fails. Plenty of free wire diagrams online to start your quest.

 

[chemgeek]

Eliminate the simple stuff first. Take a voltmeter and check for voltage at the light sockets relative to ground. If you are getting voltage at the light socket, then you have a loose, disconnected, or missing ground wire.

 

[Warrior 151]

Transistors, behind the switches, cheap to buy hard/ expensive to repair.

 

[kshaw]

Eliminate the simple stuff first. Take a voltmeter and check for voltage at the light sockets relative to ground. If you are getting voltage at the light socket, then you have a loose, disconnected, or missing ground wire.

Each of the bulbs have their own ground but there is a common power wire running from bulb socket to bulb socket. If all the lights are out, it is not a grounding issue. If you have multiple lights out but not all of them, follow the power down to where the first bulb is out and apply some ACF-50 to that connector and maybe use a wire brush. If all the lights are out, replace the transistors on the Piper dimmer or reset the breaker. If only one light is out, make sure that the socket is plugged into the panel and the bulb is good. If you still cannot get the dimmer to work, don't spend a bunch of money fixing it or the rheostats; instead, bypass the dimmer with a MaxDim dimmer (those are FAA approved) https://sarasotaavionics.com/avionics/maxdim-mini

 

[Dan Thomas]

Any circuit has voltage across it, amperage in it, and loads and sometimes controls that present resistance. The dimming circuit is engineered to provide dimming throughout the range of the dimmer, and that depends on the amperage of the circuit.

If you replace incandescent lamps with LEDs, you lower the amperage dramatically, and the dimmer now has little authority over those LEDs. They will remain bright until they abruptly extinguish as you turn the dimmer.

That's all separate from what the malfunction involves in the first place. It might be a bad transistor, might be a bad potentiometer (it controls the transistor) or there might be bad breaker in the supply circuit. One HAS to know how to use a multimeter to troubleshoot, or you just end up replacing stuff until the problem goes away. That gets expensive.

Better to do the troubleshooting with the old bulbs inplace, or confusion will reign.

 

[kshaw]

The Superbright LED bulbs work very well with the Piper dimmer. Hundreds of Piper pilots have made the transition. The only difference that I noticed after the conversion is that the Piper dimmer is not as linear with the LEDs as it is with the GE53s.