Converting Whelen 900s/Similar Scene lighting to LED?

[qcdstick]

Hmm, not sure what the one screw lens is. Looks like a strobe? Your turn signals look like 900 series. It usually says on a sticker on the back or stamped on the plastic. Old 97 series had 4 screw holes in the flange holding it on. Newer 900 series combined the flange attachment with the 4 screws holding the lens on. Simpler and cheaper. The newest LED 900 stuff is flush mount, with no giant hole needed in the ambo box.

The single screw holds the lens on, then there are 4 screws holding on the fixture that are revealed once the lens is off. Everything on the ambulance except for the turn signals is the single screw, there are some tabs at the top that you hook in and then it pivots down and locks with the single screw. The module is a 2003, if that helps? I'll pull a few and see if the hole patters match and what may be stamped on the fixture itself.

The clear ones on the back are both rear flood lights and reverse lights, but they have the "+" style pattern like the flashers above and on the sides. The scene lights on either side have different lenses without the "+" as discussed earlier in the thread which should be proper dispersal for scene lights. Like everyone else, I'd kind of like fresh clear lenses, these seem harder still to find!

That's odd. I post them to Instagram which links to Facebook. Both should be public and viewable.

I just went and opened it with a different browser, and can see the images no problem. Could be a firefox issue (strange, but possible i suppose), or maybe more likely my ad blocker is nuking those images for some reason. In either case, the issue appears to be on my end.

 

[2Fass240us]

Got another coat of FlexSeal on the roof and hit the lightbox side. It looks much more at home with everything the same color.

Next up: 1) Paint inside of recessed box black, 2) Mount the LED flood, and 3) Post light output comparison to the Whelens.

 

[2Fass240us]

Finally installed the rear light box. Before:

During:

After:

Upper middle is the new third brake light, lower middle the reverse light. None of it's wired up yet, but I plan to do so this week and take pictures of the light output over the weekend.

 

[2Fass240us]

LET THERE BE LIGHT!!!

Comparison to original scene light:

Both hooked up...might need to aim these down a little haha.

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[markc2004]

Anyone have success finding aluminum blanks to cover over the Whelen 900 red lenses?

 

[eporter]

Would that be so you could mount a light to a hole cut in the plate that replaces the lens? Not sure how much room there would be, but it could look more finished than no housing, and a flat plate with a light mounted.

If no light is wanted, most people either remove the whole light housing and then put a plate on, or just spray paint/wrap the red lens.

 

[4671 Hybrid]

Realizing that this is a few months old, I thought it might still be helpful to post up this light I found on Amazon.

www.amazon.com/gp/product/B093SRS8VV/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

After seeing a Whelen replacement bulb was runinng about $75 and a G4 bulb would fit but just didn't seem that bright, I instead splurged on a $7 flat LED that should fit the housing since it's only 1.3" deep.

Will report back this week on whether or not it fit behind the original lens and how much modding I had to do.

 

[rlrenz]

I've seen other people fight with Whelen conversions, and I'm betting you'll have to cut a square hole in the 900 reflector, and then epoxy the LED into place.

 

[eporter]

There may be heat issues without adequate venting for the LED light. You’ll likely need to make some holes in the existing reflector or just cut most of it away.

 

[rlrenz]

Since you're replacing a 50 watt halogen bulb that survived in the fixture without ventilation, I don't think you'll have a heat problem

 

[eporter]

Since you're replacing a 50 watt halogen bulb that survived in the fixture without ventilation, I don't think you'll have a heat problem

Those LEDs linked are 75watt. I’d be less concerned with the Whelen lens/housing, and more concerned about the actual LED light/circuit board. I’ve had some fry themselves due to insufficient venting. They’ve got aluminum fins on the back, so as long as those have airflow (big cutout in the housing and no insulation in the way) it should be ok.

 

[rlrenz]

Wow! I didn't realize they were 75 watts! Ambulances with halogen lights should have enough room behind the lights for fins, but you won't have much air flow. At the price you mentioned, they may well be more failure-prone than a heavy duty LED

 

[4671 Hybrid]

Great news, the lights fit in the pod without sticking out past the lens. Other than drilling a hole for the mounting screw, I didn't do anything else (actually drilled two because the first hole was a tad high). My housing already had a cracked hole (visible in the straight on and rear pics) so hopefully that extra hole(s) is enough ventilation. The old bulb must've touched the lens at some point because the lens had a burn hole in the inside plastic and is a bit yellowed.....and that's probably what caused it the bulb to break. I'd like to clean up the lens a bit and get it back clear again.

I had it on for 5 minutes and while it's plenty bright (100 ft away was easily visible), it didn't seem to generate much heat....I can't imagine using them more than an hour at a time so I guess we'll see. Since they have a one year warranty, some torture testing is on the menu to see how hot I can get them (I have a small EGT probe I can put in the housing) and I'll reply back with results.

 

[eporter]

Hey that looks like a good fit for the price. Simple! That LED unit has a bunch of cooling fins on the back, I’d give them some airflow to work with. Cutting a big rectangle out of the back of the housing would be best. Or swiss cheese the back with a big drill bit. Heat kills LEDs, especially cheap ones.

 

[Bikersmurf]

X2 on big vent hole. I’d cut a couple big ones in the reflector.

75 w of LED is crazy. The two 5w LEDs in mine are brighter than the pair of 35w halogens they replaced.