I currently have the OEM hood switch wired into the same trigger on my after market alarm that the trunk switch is wired to. It seems to work ok for a week or so, but sooner or later the hood switch stops working completely and fails in the triggered position (that is, I get a trunk light on my dash until I disconnect the hood switch). I have replaced the hood switch with a new one and the same thing happened after a week or so. I'm thinking that something is frying the OEM hood switch.

I am thinking about isolating the hood switch from the rest of the electronics with a diode. I went to the local electronics store and they had many different diodes to choose from. Can anyone recommend a specific part number, or simply a spec for a diode that I should use for this application? Also, does my logic make sense, or am I overlooking something obvious?

Thanks for any help!

 

You're definitely overlooking something. The switches in those hoodpins are definitely for low current (<100mA, give or take), so if something is truly burning it out (which I have my doubts about), you're pulling a lot of current through that switch.

If you have a multimeter, place it inline with the hoodpin and see how much current is flowing throug hthe switch. Better yet, just hook the wire going to the hoodpin to the meter and the other sid eof the meter to ground (forget about the pin altogether)... is it still pulling a lot of current? Anything more than a couple of mA is too much.

Check this first and report back.

 

If you are getting a trunk light indicator with your hood open, then the switch is working fine. Basically whenever the trunk is open, it sees a negative, same thing with the hood switch. The negative triggers the dash light indicator. As for a diode, you can pretty much use any diode to isolate the two trigger points. remember, silver band side is positive flow.

 

He's saying that it works for a couple of weeks and then fails, not that the light turns on/off with opening/closing of the hood.

Also, not just any diode will do. There are different types of diodes... for example, using a zener here would be a bad idea. He needs a rectifier diode (although a switching diode would work in this case)... Radio Shack usually has a good supply of 1N4001 in stock for less than a buck. Stripe should go towards the most negative side of the circuit (i.e., towards ground).