Hood Pin Alternatives

What other alternatives do you guys use for hoodpins? I know there are mercury switches, but i dont feel like adding $10 to an install just because there is no place to install a pin switch.

I have seen magnetic switches where you put one piece on the hood and the other respectively on the vehicle (you know what im trying to describe). These could work. I'm not sure if there are ones made specifically for automotie purposes, or if you can just get anyone and make it work.

I also was trying to think of a reliable way to have the hood close the circuit when it was shut since I have the option to use a NO or NC hoodpin.

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J Rilla

Owner/Installer

That would be a good idea, althou they would cost more than the mecury switch.  I have installed a cheap rocker switch under the dash, and informed the customer to flip it when work is to be done on the vehicle.  Most of the alarm/remote start shops dont install hood pins.  Being in N. Montana, when working on a vehicle, you always check to see if it has a remote start, chances are.... it does.  Good thing is that most of the newer cars that I have been installing on, have a hood pin wire in the drivers kick panel.  Wish they all had that.

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Hak

Siemens Autostart

If the vehicle in question has a OEM indicator lamp on the interior dash, as there is for a trunk open indicator. You could tap into that wiring harness to activate the alarm system.

If you are doing so, please ensure a 1-2 amp isolating diode is placed in series to prevent feed-back to the system.

The magnetic switch you are referring to is called a magnetic reed switch. You may purchase the very same item through Radio Shack, which they sell for home use.

They cost about $4.00 USD.

Another alternative to a pin, reed switch, is using the factory hood lamp, and a simply voltage sensing circuit to detect the voltage drop, which will then activate the alarm system.

Regards

EVIL Teken...

I can't think of one vehicle that I have done in the last ten years or so that i haven't put a hoodpin on, except maybe a vw van, because the motor is in the back. There is ALLWAYS a way to do a hoodpin. I'm sure if I didn't install one on a vehicle at work that i would prob not have a job anymore. I don't I know of anyone around here that would ever consider installing a r/s without one. Don't get me wrong, I'm not trying to sound all high and mighty, too each his own, but that's just the way it's done around here. I would feel pretty bad if someone got hurt because I was too lazy to run one more wire under the hood. Do you have any examples of vehicles that you are having trouble with?, i might be able to help you out.

Just my two pennies.

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I was wondering the same thing....especially about using the factory wire for the hoodpin (or for the light under the hood if one exists). So if you hook up to the wire under the dash, you have to use a diode? (Stripe facing towards the alarm, right? )

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CPGOOSE,

The diode needs to be forward biased. Meaning that the striped (cathode) side of the diode is facing toward the light bulb. But, you will varify that fact with your DMM as to which lead is more positive, than the other.

(The diode will be placed in series, on the positive side of the bulb lead, which ever orientation that may be.)

Regarding the use of the hood pin. There are a variety of hood pins that are designed to have a shorter travel and body style.

The following are just one brand that I know the model numbers for, but other well known brands carry them as well under their own unique identifiers.

CRIMESTOPPER SECURITY'S:

CS-111: Is a short travel metal door pin

CS-107: Is a chrome plated oval housing with a round metal ball bearing for use in heavy doors, but can be used for the same thing.

CS-119: Is the N.O magnetic reed switch, which is hermetically sealed and U.L. listed.

CS-131: Is a short travel adjustable plastic shaft pin switch that has a rubber boot covering. If you have ever seen a BMW, that is what the switch looks like.

If there is a vehicle that does not afford a install friendly placement for a hood pin, one of the above items will address those concerns.

In the worst case scenerio, a simple metal bracket should be fabricated, and affixed to the vehicles chassis, with a bolt, and not a sheet metal screw.

Regardless of the make or type of hood pin, a metal *star washer* should be placed during the installation, along with a simple dab of dielectric grease to inhibit moisture and corrosion of the mounting surface.

This simple $0.02 part is what makes the difference between a trouble free 3 year install, to a 10 year install.

Regards

EVIL Teken

Can someone explain how the mercury switches or the magnetic switches work?

Do the mercury switches just look for the mercury to move (like if the hood opened)? What would happen if you parked on a hill?

Do the magenetic switches need to have hood-to-car contact, like with the hoodpin switches?

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cpgoose wrote:

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Do the mercury switches just look for the mercury to move (like if the hood opened)?

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EVIL Teken: Yes, the better units such as the one offered by Ungo, are electronicly calibrated to compensate for incline, drift, and low level wind conditions that would rock the vehicle, but not set off the alarm.



[quote]What would happen if you parked on a hill?[/quote]

EVIL Teken: The better units compensate for the attack angle by electronic means, or a counter balance *balace* tube within the unit.



[quote]Do the magenetic switches need to have hood-to-car contact, like with the hoodpin switches?[/QUOTE]

EVIL Teken: The two terminals N-P must be within the limits of its magnetic field. Some have zero seperatio allowed, others allow almost 4 mm to be spaced, prior to breaking the contact, and sounding the alarm.


Regards

EVIL Teken . . .

Well, I guess we would all agree that snagging a wire under the dash would be the easiest way....but which do you think is better...the magenetic switch or the mercury switch?

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If a normal hood pin can't be used, i use a right angle hood pin mounting bracket made just for hoodpins.

derek, where do you get those brackets from. They seem simple enough to make yourself, but then there is an aesthetics issue. I saw them for $2 a piece, and thought I should be able to get a better deal for a bulk order.

I was about to order some mercury switches, but they are too expensive for the purpose they serve. I mean they dont save any time, so why spend $7 on something that doesnt make the job easier.

It seems to me that either a right angle bracket, or even a straight bracket would be all you would ever need.

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J Rilla

Owner/Installer

In my application I would lean toward using a magnetic reed switch, instead of a standard hood pin.

The reason is because there is no moving parts to break, corrode, and bind. It is not affected by shorting to ground due to moisture and water path ways. Heat is less of a factor when compared to a hood pin.

Once the magnetic reed switch has found a suitable location, and its placement is varified by activation, and clearence.

The service life of the magnetic reed switch exceeds 10 years. This assumes you purchase those units that are made from high quality iron ore's (sp).

Which are perminent magnetics, and not ones that are made, via magnectic induction, these sort of contacts are always used in low cost units found in the hobby stores and those retailers looking to supply all things for all people at a low cost.

Just my thoughts on that...

Regards

EVIL Teken...