Changing pattern in Whelen UHFPOS flasher

[nluszcz]

Ok, I'm stumped. After a 6hr session trying to get a headlight flasher installed in my Silverado, I finally got most of it done. Still a pesky issue I haven't had a chance to figure out (trying to mesh a headlight flasher relay and a low-beam override relay together is a b$%@*; so far, I have three relays and a diode involved). But the easiest part I just can't figure out from the directions, is how to change the pattern! The directions say to apply 12v to the white/purple scan lock wire just like any other Whelen. But..... the only white/purple wire is an unbroken loop coming from and going back into the epoxied unit. How do I apply 12v to it?? My options are:

1. Like the oooold (wish I hadn't sold it ) 2150A, you cut the various loops to get the appropriate pattern, so I could cut the wire and see what happens.
2. I could cut the wire and apply 12v to either end of it (which end?? they're identical)
3. I could cut away some insulation or use a needle cable to apply 12v THROUGH the loop without cutting (I tried this and it sparked, without changing pattern)
4. ???

Of course, I got to this stage at 4:50 on Friday, so I can't contact the amazing awesome super duper helpful tech support staff (seriously, I looooove these guys at Whelen!!) until Monday. Anyone know the answer before then?

 

[shues]

The loop of wire you describe should be one of two. These are not scan-lock wires. Here are a couple of installation manuals that explain Whelen's older four-pattern flashers and how to cut or not cut the two loops of wire to select the pattern of your choosing:

• https://www.whelen.com/install/136/13614.pdf
• https://www.whelen.com/install/136/13633.pdf

 

[nluszcz]

Hmm, I wonder why mine was mislabeled as a POS with no suffix letters. Yes this one has the two loops, white/red and white/purple. My old flasher I loved had the loops, but the manual that came with this one swears there is a scan lock cable. Now, how do I figure out which one it is lol. Thanks a bunch!!

 

[shues]

If I recall correctly, I once had a handful of NOS Whelen UHFPOS, with no suffix, with the looped wires for pattern selection.

Is there a second looped wire in white/red on yours?

 

[nluszcz]

Yes. I'm sure you nailed it, I'm just confused as to why I have it lol and why it doesn't match the instructions. Thanks a bunch!

 

[shues]

Did yours come in a cardboard box or in a plastic bag? There was a brief period of time, after Whelen quit using cardboard boxes for small items, and before they began printing the instructions on the bag itself, where items came in relatively plain plastic bags with printed paper instructions inside.

 

[nluszcz]

Bag with printed instructions on the bag (no paper)

 

[shues]

I found the original version of the instruction for the UHFPOS (with no suffix), Form 13635, which shows the two wire loops, and is dated September 17, 2001, here:

https://web.archive.org/web/20060311180445/http://www.whelen.com/install/136/13635.pdf​

I found an updated version of the instructions for the UHFPOS (with no suffix), Form 13635A, which also shows the two wire loops, and is dated April 12, 2006, here:

https://web.archive.org/web/20070324155854/http://www.whelen.com/install/136/13635.pdf​

I found the most current instructions for the UHFPOS (with no suffix), Form 13625B, which shows the scan-lock wire, and is dated July 1, 2010, here:

https://web.archive.org/web/20150701092801/http://whelen.com/install/136/13635.pdf​

I would imagine that your must be printed with Form 13635B, and must be dated July 1, 2010.

Does your flasher have a manufacturing date listed on its label?