PDA

View Full Version : Hood and trunk protection



ejschultz
06-08-2009, 07:10 PM
Okay, no one can seem to help me on my impala forum so I'll try here. I've got a 94 caprice and I want to know if it is possible to use the hood/trunk lights to set off the alarm. As far as the hood goes, I've tried negative and positive triggers using the proper wires and have had no luck. I've got a multiplexer on the alarm for use with hood/trunk pins, but I'd like to stay away from that route. Any suggestions will be greatly appreciated.

bubbagumper6
06-08-2009, 10:40 PM
You should be able to use the trunk light to set the alarm off. Your alarm should have aux inputs that trigger either when they see 12v or when they see ground. If it's 12v all you have to do is hook it directly to the trunk light wire. If it's ground, then you just need to use the trunk light wire to trigger a relay that connects the wire from the alarm to ground.

ejschultz
06-08-2009, 10:45 PM
That shouldn't be a problem. I know I've got a positive trigger on the alarm because my interior lights use it. I'd just have to tap the positive trunk wire into that too. As far as the hood goes, I have no clue how to get that light working. Neither wire shows 12 volts or any change in voltage when the hood light is on. Would this require a relay? I could probably set up a relay to act as a negative trigger if this is the case. Any thoughts on this?

bubbagumper6
06-08-2009, 10:48 PM
If you have a hood light, it has to have a positive and negative wire...check the wires again. Not sure why neither showed 12v.

Why don't you want to use pin switches?

ejschultz
06-08-2009, 10:54 PM
I don't think it looks too clean. Also, I don't really know where to put it on my car. I'd like to use the light if at all possible. Even though I didn't get a voltage reading, I tested every combination of positive and negative triggers with both wires coming off the light. None worked. I also tried the multiplexer wire because that's usually the one you use with pins. That didn't work either. I figure that no matter what, there has to be some current in the line when the light turns on. If i tap into the negative wire on the light and use a relay, there should be enough current going through the wire when the light turns on to activate the relay. Then I could just hook up the relay to ground and the negative trigger of the alarm. That way when the light lights up, the relay is activated and the negative trigger of the alarm can read the ground which should set off the alarm. I haven't thought of that until now. Do you think it would work?

bubbagumper6
06-08-2009, 10:59 PM
When your testing the wires, try putting the negative probe on the chassis of the car, (negative terminal of the battery would be ideal), and probe the others with the positive probe, because like you said, they're HAS to be current going through one of those wires.

If you still can't find it, give what you said a shot. Can't really hurt anything and it wouldn't be hard to hook up.

ejschultz
06-08-2009, 11:01 PM
I'll test it again tomorrow. If I can't find any voltage for whatever reason, I'll go and get another relay and try that. I'll let you know what happens with it.

Worlddre
06-09-2009, 10:10 PM
:fyi: not all things are positve trigger so the trunk light may be negative trigger as well.. If you the light is not showing a change that get a hood pin or ball bearing switch can call it a day.

ejschultz
06-09-2009, 11:16 PM
I know the trunk is a positive trigger because when I open the trunk and the light comes on I get 12 volts on my multimeter. When the lights are off, I get nothing. The hood is really throwing me for a loop. I was going to attempt to do it with a relay today, but I had other plans pretty much thrown at me. My grandfather finally gave up driving, which he badly needed to do, but now he's been bugging the crap out of me to take him everywhere. It's usually an all day ordeal, which happened to be the case today. Tomorrow it's supposed to rain, so that'll probably hinder me from doing it tomorrow as well.

Worlddre
06-10-2009, 07:51 PM
just use an actual hoodpin....the trunk is supposed to be wired to the multiplex input wire :fyi:

ejschultz
06-10-2009, 08:17 PM
I've got a mercury switch in the trunk for the trunk lighting. I'm pretty sure I can use a positive trigger for that. When I open the trunk voltage goes from 0 to 12 volts. That would be a positive triggered trunk light. Correct?

Worlddre
06-10-2009, 08:54 PM
yes

ejschultz
06-10-2009, 08:57 PM
Well, that'll get tapped into my positive trigger then with my dome lights and I'll more than likely end up using a pin for the hood.

ejschultz
06-22-2009, 07:31 PM
Okay, for those of you who gave me ideas, thanks. What I ended up doing was using 2 relays to simulate hood/trunk pins. It didn't work. Nothing ever does work. Anyways, I tried this:

http://i636.photobucket.com/albums/uu88/ejschultz/ALARMRELAY2.jpg

Supposedly it's worked for others with Caprices/Impalas. The blue wire 6 on H1 that is mentioned is the multiplexer wire which is normally used for hood/trunk pins. I hooked it up exactly as this shows and with the black wire connected instead of the orange wire. Nothing. There are two wires for the trunk and hood (obviously). One is orange (12 volt) and one is black (ground). The orange is constantly hot even when the hood or trunk is closed. The black has to have a small current with the light on. I figured this would send a very small current to the relay when the light kicks on, but I think the current is too small to trigger the relay. Is there an automotive relay that triggers at a very low current? I think it would work if I could get a more sensitive relay. I'm already using the DEI mini relays 8616.

nuugen
06-30-2009, 04:49 PM
Those lights probably have a roller-ball switch to trigger them when the hood/trunk is lifted..The orange is the constant feed and the black is the ground..When the hood/trunk are lifted beyond a certain angle the roller ball moves and closes the circuit, thereby illuminating the light..You won't really be able to tap into those...To make a clean install, I install my own mercury or roller-ball switch right next to the hood/trunk light, ground one wire and run the other wire to the hood/trunk input on the alarm...Loom the wire and tie it to the oem wire for a nice finished look..You can also look for a current sensor module(DEI makes one), but those are pretty prone to false alarms..
Regular hood pins ****, every car is different on mounting points and they rust/corrode after time and either stop working or give false alarms..

ejschultz
06-30-2009, 05:35 PM
Where do you find the roller ball switches? I know you can't get mercury switches anymore. I haven't really looked too hard for a roller ball switch.

ejschultz
06-30-2009, 05:55 PM
Nevermind, I found some. They are actually mercury switches. About 6 bucks each shipped. Not too bad. If only I would have known before putting all that time into it. I've got a guy right now on my Impala forum playing with it right now trying to figure out the lighting. I told him that he orange is constant 12 volts and the black is ground but he wants to check it all out for himself. I'm going to order those switches to finally get this 100% working.

bubbagumper6
06-30-2009, 06:14 PM
You can still get mercury switches...just because it's toxic doesn't mean they outlawed it :)

nuugen
06-30-2009, 06:19 PM
DEI 8610 is the mercury switch, 8623 is the roller switch, both are available on the bay...

ejschultz
06-30-2009, 06:42 PM
You can still get mercury switches...just because it's toxic doesn't mean they outlawed it :)

Automotive mercury switches got some pretty strict restrictions in 2005 or 2006.


DEI 8610 is the mercury switch, 8623 is the roller switch, both are available on the bay...

I found an 8611 mercury switch on eBay and some off brand at parts express I think. I can get 2 of the off brand ones for the price of one of the DEI switches. I think I'll probably go with DEI though.

ejschultz
08-25-2009, 09:22 PM
Well, 2 months later I finally got the DEI 8611 mercury switches and installed them. Everything works perfectly now. If I pop the trunk with the remote, the alarm does not sound, and if I use the button inside or the key, it does sound. I believe this is because the alarm is opening the trunk when I use the remote so it knows to ignore that trigger temporarily. They were fairly simple to install, especially because I already had all the wiring still ran from when I attempted to use the relays. Next time I'll know to just **** it up and buy the mercury switches to save myself time and a headache. Thanks for all your guys help.