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| Subject - automotive toggle switch application | |
| v8ramair |
Forgive me for posting a newb question, but I wanted to customize some switches in my car. I purchased a few toggle switches, but I don't know if they would work. Their ratings are 3A @ 125VAC/ 1A @ 250VAC. I need this, of course, for a 12VDC application. One is to turn on daytime running lights (uses 18 gauge wire from a 12V power source), the other is to turn on the cooling fans (connects directly into the PCM computer, not the fans), and the last is to control a motor for the butterfly on an electric exhaust cut-out. Can I use these switches for these applications? Thanks in advance for any advice 
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| JimmyDee | To answer your question, I will have to know the amperage of each of the devices you are planning on controlling. Keep in mind the highest amperage rating of your switches is 3 amps. Not really a heavy duty switch but I not sure what your needs are. Jim |
| v8ramair | Thanks for the reply. I'm not sure of the exact specs of the amps on each application though. All I know is that it's recommended to use a 30 amp fuse for the daytime running lights. I don't think I have to worry about the fan switch because I believe it just sends a small signal to the computer telling it to kick on the fans. Rather, it's not powering anything major. And I have no clue on the amps of the electric motor. It's about 1.5" in diameter, and just strong enough to move a butterfly in order to open/close the exhaust. I'm still a new guy when it comes to calculating the specs, but since the switch is good for 3A at 125V...375 watts, and I'm using it at 12V, should it be good for 375W/12V = ~30 amps? Lastly, I just heard this from someone over in an automotive forum: "No you should not use A AC switch on DC the air gap is not that wide it will work but will not last very long. Go to a parts store an a DC switch." Is this true? Thanks a bunch again. |
| JimmyDee | quote: Not so. 3 amps at 12 volts will = 36 watts. You can not freely interchange the wattage of the switch. If it is rated at 125 volts that has nothing to do with the amperage. The amperage rating of the switch does not change when lowering the voltage. I'm thinking that if a 30 amp fuse is required for the lights, a 30 amp switch is required for them also. Don't be fooled by the fans being controlled by a the PMC, there can be some large controling electronics invloved. For the cost difference of the switches, I would use 30 amp ones and call it good. quote: Yes this is correct. Radio Shack will have them also. Jim |
| v8ramair | OK, thanks for all your help. I just found out each light is worth roughly 2.2 amps, so I guess there's 4.4 total. I can pick up a few 6 amp switch at Radio Shack that will be small enough to hide in the ashtray area. |
| JimmyDee | Probably but I'm sure you can purchase a heavier duty one that is the same size and it will probably last a lot longer. I would install at least 15 or 20 amp one if you can find the physical size you want. Jim |