DEI Viper PC 500 HF
by: Andrew Krause

After years of installing alarms, I have come to praise highly DEI's products. Now, with respect to the fact that I am a disgusting little schill when it comes to Directed Electronics, and could quite possibly be the biggest corporate kiss ass (the only barrier to which is that I am not an employee of DEI), I have worked with a wide variety of alarms. While I will admit that there are others with more features, lower costs, or similar technologies, they all suck nonetheless.

Pluses and Minuses

The first most obvious minus is that most vendors are required to install DEI's product. If you are a DIY'er, and simply insist on installing it yourself, you usually can, but they vendor does not have to (and probably won't) return your install fee. OTOH, if you have the means, and you are a good installer, go for it. The install is typically only about $80.

On the plus side, and there are so many, this little Viper has a lot of bite. For starters the actual alarms package size is only 1"x3"x4". This small size makes it an easy squeeze into many small spots in your dash, or even your floor board or kick panel. I have even managed to locate one inside the kick panel frame member.

This alarm is part of the PC series. On the side of the brain, there is a small 3 pin port, which can be plugged into your installers personal computer, or the Bitwriter handheld programming computer. With easy menu driven setup, you can almost completely customize the operation of the alarm.

Like other Viper alarms, you can still program the unit using the valet switch. The valet switch itself is now more versatile than before. For starters, you can no longer disable the alarm with one press of a button. It'll now take up to five, and you can program the number of button presses that it takes to shut the alarm up. Also there is the use of a ghost valet switch. Instead of using a pushbutton, you can simply connect the valet switch input to a positive trigger on a vehicle (the brake pedal, for instance), and use that trigger to put the alarm in valet. No buttons, no clues.

Also, the transmitter/receiver pair is HF, and Code Hopping. HF, or High Frequency, means that your receiver communicates at a higher frequency than mere mortal transmitters, so that it is less vulnerable to interference from other radio transmitters. HF also gives greater range. Code Hopping, on the other hand, uses a special code transmitting scheme. Instead of using the same code to arm and disarm, it uses a different code each time....up to 18 quintillion codes, all used in no particular order. This makes it difficult for a would be thief to catch your code, and use it against you.

The 500 also comes with the Super Bright LED, and it is bright. Now a little trick with DEI's LED's, is that you can actually remove the LED element from it's housing. Simply use a pair of pliers to squeeze the housing, and the plug will pop out of the bottom. You can then use a 7/32" drill bit to create a hole snug enough for the LED to mount into. The actual LED is a clear epoxy casing, so it blends well with any dash, and it is small enough to be unnoticeable, until it blinks. Did I mention it is Super Bright?

Another feature is the Stinger Double Guard Shock Sensor. This unique sensor is based on impact not subtonics, so it' knows a little better the difference between a hammer and a bass hit. Properly set, this sensor provides great first stage protection, and second stage alerts. Light impacts set off a series of 8 rapid beeps, while "heavier" ones set the alarm right off.

The harness on DEI's alarms have been redesigned. They can now handle much more current then before, and have a locking mechanism that guards against the harness merely pulling (not that that was ever a problem). They follow the same pignut as the old harnesses, and the same color codes.

Features abound on this unit, and one special feature makes them all worthwhile: Owner Recognition knows which remote is who's, and adjusts the features accordingly. So, if your significant other (presumably of the opposite sex) prefers for the alarm to not automatically lock the doors, you can program it not to with their remote. When she disarms the car, Owner Recognition recognizes them, and changes it's whole setup.

Other features include a channel 2 and 3 output and a dome light supervision output suitable for driving relay. Channel 2 activates after a few seconds, which is great for trunk release (so you don't pop prematurely). Channel 3 outputs instantly, but more interesting is that you can set channel 3 to latch. This works great for me, since I use channel 3 to activate my headlights. Previously, I used a pulse timer relay to turn the headlights on for 30 seconds. However, sometimes 30 seconds was not long enough, and other times it was too long. With the latching output, I turn it on and off with the press of a button.

Getting back to the transmitters, you can reprogram the transmitters in a number of ways. By default, I is Arm/Disarm, or Panic if you hold it down. II is silent arm if used in conjunction with I, or channel 2 output if held down for a few seconds. I and II at the same time is Channel 3 output, and III and IV are..well...useless. However, you can reprogram these buttons, and the receiver actually recognizes 7 channels. With some creative reprogramming, you can reprogram the III and IV buttons to work any other HF alarm, so if you have a second vehicle, you can actually control it from the same transmitter as your car. However, this is only true if the transmitter has a green light. Older HF transmitters have red lights, which denotes a different code hopping scheme. On the other hand, you can reprogram your own remote to have separate buttons for arm and disarm, a dedicated button for channel 3, or just relocate buttons to do different stuff.

The Install

Although I frown on it for most vehicles, I installed my alarm in the actual dash of my 96 Nissan Pickup. The alarm tucked nicely up below the speedometer, which ensured impossible access without removing the steering column shroud and dash. Wires were run together and taped/loomed to hide them. All connections were soldered and taped with 3m Super 33. Any heavy gauge connections are reinforced with wire ties to keep the stress off the actual solder joint. The connections for starter kill, ignition, head lights, and parking lights were made in the steering column.  Many Bosch relay sockets can be linked together, so I added the two for headlight activation to the starter kill relay, and mounted them beneath the dash by screwing them to a metal plat that also housed the diagnostic connector. The other two relays (one for dome light supervision, and one for the dual sirens) were mounted in hidden spots.

The addition of a second siren under the dash should make trying to find and disable the alarm a painful experience. The crime stopper siren is a shrill 126 dB, and it is truly painful in your face. The output of most alarms is fine for a single siren, but you must add a relay to power a second siren. It's also important to mount the siren out of the way.

I actually had a number of LED's laying around from previous installs I had done. I elected to mount an LED, in it's casing, in each of the front corner lamps. This way I can check the status of my alarm visually by merely looking out my window. The output of the alarm is not enough to drive both LED's as brightly as the one, but they are still visible.

The channel 3 output drives a set of relays for the headlights, and as I already mentioned, I set the output to latched. I had trouble getting the ghost valet feature to work, so I mounted the switch. You can't disarm the alarm without putting in the correct number of inputs, so I could mount the switch in the middle of the dash for all it's worth.

I programmed channel 3 output to the III button on my four button transmitter. I also programmed the unit for silent arming, automatic arming, and automatic locks. When you get it and start the car, it'll lock the doors on you. When you turn the ignition off, it unlocks them. Dome light also activates with arm/disarm.

Overall, the PC 500 HF is a great little unit. It's list of features is double that of any other alarm at it's price point, and the unmatched quality of DEI is something I can testify to.