Light bar singing and witing issue
#1
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Year: 1990
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Light bar singing and witing issue
Ok so I have my light bar mounted on the drip rails in a hooligan mount. When I drive it sings becaus of the cooling fins and the air flow. Has any one experienced this and how can I fix it ? Also where should I run the wires. Someone here I forgot the user name ran then through the weather strips on the door but mine has a different style strip
#3
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It's not the mount it's the fins on the bar are vibrating. I'm going to put a strip of silicone in the fins vertically to just isolate the vibes.
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It's probably the air between the fins that is resonating, like air in a whistle. You just need to break up the airflow so that it doesn't resonate. Can you post a pic?
Keep in mind that cooling fins are there to provide more surface area for heat to dissipate into the air. If you put anything on the fins directly, you reduce their effectiveness. I don't know how hot these get, but if those fins are necessary to keep the unit from overheating, putting silicone in or on the fins themselves may cause you worse trouble than singing.
Keep in mind that cooling fins are there to provide more surface area for heat to dissipate into the air. If you put anything on the fins directly, you reduce their effectiveness. I don't know how hot these get, but if those fins are necessary to keep the unit from overheating, putting silicone in or on the fins themselves may cause you worse trouble than singing.
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I also just ran mine behind the window trim, into the fender and then into the engine bay. Mine doesn't whistle at all, and I used the stock aluminum mounts just bolted through the roof
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is this the hooligan mount with the big air dam sitting right behind the light bar?
i mentioned my mounting as there's no reverse buffeting going on...cleaner aerodynamics
i mentioned my mounting as there's no reverse buffeting going on...cleaner aerodynamics
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It's probably the air between the fins that is resonating, like air in a whistle. You just need to break up the airflow so that it doesn't resonate. Can you post a pic? Keep in mind that cooling fins are there to provide more surface area for heat to dissipate into the air. If you put anything on the fins directly, you reduce their effectiveness. I don't know how hot these get, but if those fins are necessary to keep the unit from overheating, putting silicone in or on the fins themselves may cause you worse trouble than singing.
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#8
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Yes I'll get pics at lunch. It's the air entering the fins that's causing it. I took some silicone and just ran two beads vertically isolating all the fins on each side about 4-6" inboard from the edges. The strip is less than 6mm wide and isn't going all the way into the fins just enough I hope to stop the noise. And I'd like to run it behind the Windsheild trim but the harness coming from the light bar is pretty fat and I Dont Know how much room there is to stuff my harness wires into it.
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You've kind of created the perfect environment for noise. Given the fins, and where the light bar is mounted, which causes a high volume of high-velocity air to slide up the windshield right at the back of the light causing resonance.
I agree with others that you don't want to put a bunch of anything in the fins and reduce their effectiveness.
You might try this...
Find a piece of metal about as long as the light bar, and about 2-2.5 inches (based on photo) wide. It can be just about anything. Aluminum bar stock about 1/8" thick from Home Depot comes to mind, and it's cheap, and it won't rust. Drill about 4 holes in the bottom fins of the light bar and corresponding places on the bar stock and mount the bar stock to the light with a few screws. You're just trying to create an air damn to keep so much wind from flowing between the light and windshield. The windshield is curved, so I'd keep the bar stock at least 1/4 - 1/2 inch away from the glass at the nearest point to account for vibration, water drainage, and cleaning. Try that and see if your noise quiets down. If so, you can mount it more permanently with more screws or pop rivets and paint it satin/semi-gloss black to blend in with the light. A few holes in one of the cooling fins isn't going to make any structural difference, and if anything, you're adding additional heat-sinking.
I agree with others that you don't want to put a bunch of anything in the fins and reduce their effectiveness.
You might try this...
Find a piece of metal about as long as the light bar, and about 2-2.5 inches (based on photo) wide. It can be just about anything. Aluminum bar stock about 1/8" thick from Home Depot comes to mind, and it's cheap, and it won't rust. Drill about 4 holes in the bottom fins of the light bar and corresponding places on the bar stock and mount the bar stock to the light with a few screws. You're just trying to create an air damn to keep so much wind from flowing between the light and windshield. The windshield is curved, so I'd keep the bar stock at least 1/4 - 1/2 inch away from the glass at the nearest point to account for vibration, water drainage, and cleaning. Try that and see if your noise quiets down. If so, you can mount it more permanently with more screws or pop rivets and paint it satin/semi-gloss black to blend in with the light. A few holes in one of the cooling fins isn't going to make any structural difference, and if anything, you're adding additional heat-sinking.
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Well, if those fins get hot, that silicon is gonna cook. Did doing that actually solve the problem?
Seeing how it's mounted, I would suspect your sound is coming from the air rushing up your windshield under the bottom of the fixture. The position of the light bar has created an air dam there resulting in high pressure under the bar, which is then whistling around the trailing edge of the bottom cooling fins.
Can you move the light bar forward at all? Doing that would relieve some of the air pressure under the fixture and might disrupt that resonance. Even 1/2 an inch might be enough.
If not, I would actually modify macgyver35's suggestion. I would take a strip of metal and bend it right down the middle at maybe a 20° angle, then mount that along the trailing edge of the bottom cooling fin so that it wrapped up the back slightly as a spoiler. That would disrupt the airflow over those fins from the bottom.
Seeing how it's mounted, I would suspect your sound is coming from the air rushing up your windshield under the bottom of the fixture. The position of the light bar has created an air dam there resulting in high pressure under the bar, which is then whistling around the trailing edge of the bottom cooling fins.
Can you move the light bar forward at all? Doing that would relieve some of the air pressure under the fixture and might disrupt that resonance. Even 1/2 an inch might be enough.
If not, I would actually modify macgyver35's suggestion. I would take a strip of metal and bend it right down the middle at maybe a 20° angle, then mount that along the trailing edge of the bottom cooling fin so that it wrapped up the back slightly as a spoiler. That would disrupt the airflow over those fins from the bottom.
#12
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Yeah the two stops of silicone fixed it. And that silicone won't burn off that's what we use to seal heads and oil pans and all that at work. It can take the heat.