Another great service/support experience with Griff this week that I just had to share. We are all guilty of *****ing about problems or poor service in our daily grinds, but we often don't take the time to recognize great experiences. So, on the brink of this summer's A/C season I just had to share. (As a discalimer, I am not on the payroll - just a satisfied customer who now stays cool in the summer).
The LED light on my Kuehl Variable Fan Speed Controller failed on Tuesday. Check this out:
Email to Griff 10:37AM Wednesday
Greetings Charlie,
Hope all is well with you. I have just picked up responsibility for SC in addition to GA at work and will be traveling there frequently. I am told by many that Columbia, SC is hotter and more humid than Atlanta, therefore, I am glad to be Griffiths A/C equipped!
Had an A/C incident yesterday that I want to run by you. While returning home from a Columbia yesterday there was a loud pop like a rock hitting the windscreen and something white flashed past me followed immediately with a burning wire smell. Did not know what happened initially but then I then noticed that the fan speed light was out and the white cover had blown off (must have been the white flash I saw). The A/C system and fan is working fine - just no indicator light.
Any idea what might cause this? I can tell you that I don't think the light has been working properly. Initially I got a very distinct green or orange-red color when the compressor was off/on. But for the past year, when the compressor cycles on the indicator light has flickered orange rather than staying solid color perhaps overstressing the light????
Can I replace the light without replacing the entire variable speed fan controller unit?
Thanks
-Mark
Email Reply from Griff at 12:14PM Wednesday
And, Greetings Mr. Thomas !
The LED light and the controller are independent of each other; the light simply picks up the power off the
circuit at the fan speed switch (when the switch is on power goes to green led) and the thermostat (when power flows
through the thermostat the red light comes on; making 'orange' hue). So the failure is not related to the controller board.
I looked over when we shipped you the controller, it was back in 2008.
Since then we came across an 'occasional' issue and it seemed to be only (almost only) 86+ year cars.
The issue appears to be voltage levels to the LED, too much and she pops!
I had a very frustrating time a year or so ago with another client, his car kept blowing out the LED, it got us to
step back and inspect what 'could' be the cause of the overvoltage.
The original LED's were designed for a 12v (nominal system). When we have them produced the factory tests them.
When we had this issue pop up we started testing every unit here before we shipped; plugging them all into a regulated
12v supply and burning them in perse over night up to 15v. We never had a failure however we were getting these occasional failures
in the field and what was frustrating was we could not pin down the exact car model years however they seemed to come
about with 86+ cars and randomly. We could dive into the factory circuit but there was not much help.
We sent failed units back to the manufacturer and all they could say was 'its fried, hard to tell, but can't see any issue with
the quality or assembly'.
Since we knew excessive voltage was the culprit we asked clients to review the battery voltages and came across a few that
had high voltage problems, however not all failures were with high voltage cars. And here again we are not talking about
a lot of failures, just enough to say 'hey, that's over the MTBF you would expect for this device'.
So here is the solution we came up with that has seemed to have resolved the occasional issue.
1) We upped the voltage rating from 12v nominal to 15v nominal in the design, we lost a little light output but not noticeable.
2) We are now including an ‘anti-spike diode’. Nippondenso use to have a block style diode installed on a Porsche 944's.
And other vehicle system designer's and some compressor companies do this. The purpose is to drain off the 'spike' which
is created when the clutch coil is de-energized; if a spike occurs it can run up the system and mess up with the vehicles electronics.
We will send you our latest LED model (higher 'v' capacity) and the diode with instructions today.
-Griff
Email 12:46PM Wednesday
Received shipping confirmation and tracking # from UPS.
How great is this?
Thanks Griff!
