96 Silverado No Unlock Viper 5608V + DEI 451M

I am scratching my head over this and could use some insight. I installed the Viper 5608V into a '96 Silverado 1500 using a 451M to send a positive current to the door locks. This model truck is prior to the introduction of Passlock and therefore installation was very straight forward. For some reason, I am not able to unlock the doors with the Viper. Lock does work; depressing unlock from the key fob I can hear a very faint relay click in the 451M but not the loud click of the unlock relay firing. Door switch works fine both locking and unlocking. I have tested with two different brand-new 451M's from two different retailers. In the Silverado there is a light blue and white wire for positive lock and unlock trigger. The wires were all tested and verified to send current from the car side when depressing the lock switch in the corresponding direction. I am pulling 12v for the 451M from the constant 12v orange wire in the door harness located within the kick panel along with the trigger wires. The 451M wiring is simple and only involves cutting the lock/unlock wires then splicing the 451M's relays with the coresponding car side/switch side wires. I have verified that the wiring is perfect according to the 451M's instruction manual. When you press the lock key on the fob, the doors lock and alarm arms just as it should. Pressing unlock disarms the alarm but fails to unlock the doors - the key fob generates an error tone and the parking lights flash 3 times. I am completely stopped dead in my tracks right now and do not have a clue why this install is failing to unlock the doors. I wouldn't be surprised if I am overlooking something obvious. This is only the second remote starter i've installed and my experience is lacking when it comes time to troubleshoot. All splices are soldered and well done, no chance of a bad connection anywhere. No nicks, pinches or other damage to the blue & green signal wires leading to the Viper. Anyone have any ideas?

vinrock wrote: For some reason, I am not able to unlock the doors with the Viper. Lock does work; depressing unlock from the key fob I can hear a very faint relay click in the 451M but not the loud click of the unlock relay firing.

Looks like you can't edit posts, I made a typo and it should read: "For some reason, I am not able to unlock the doors with the Viper. Lock does work; depressing unlock from the key fob I can hear a very faint relay click in the 451M but not the loud click of the lock relay firing."

2 door or 4 door? Factory keyless?

2 door crew cab. I have verified that it is positive signal so I guess this thing was equipped with keyless and my buddy just didn't get the fob from the seller. Lock works fine - only unlock fails to do it's thing. I am going to wire lock -> unlock when I get home and try an external relay to try and isolate the trouble but this is mind boggling.

What wires did you connect on the 451 and to what?

light blue and white (I am still at work right now and dont have the docs with me but am leaving for my buddies soon to work on this) The door lock wires were not in the harness described by the Triple S Customs PDF but they were in the general vicinity. I removed the door panel to verify the wires leading from the door lock switch. The light blue and white wires were then cut and I tested for signal when depressing the lock and lock buttons from the car side of the wires - each wire (car side) sent 12v when depressing the lock switch the corresponding direction. Pressing the lock button (closed padlock) on the Viper fob results in the alarm arming and the doors locking. Pressing the unlock button (open padlock) on the Viper fob results in the alarm disarming, the fob playing an error tone and the parking lights flashing 3 times - the door does not unlock.

Forgot to mention - the wiring was done in according to type C installation as shown in the 451M manual. I verified wiring about 100X to make sure I wasn't going crosseyed from too many beers.

If it has factory keyless, and is a 2 dr crew cab should be type A. meter the wires at the back of the door lock switch to make sure. Should be 3, not counting any illumination wires. 1 shows ground, 1 will show +12 at lock, and other +12 unlock.

Ok will do, i'll report back in a few hours.

Ok, i'm over here now and have done a bit of debugging. No dice. I switched the wires for lock/unlock - in this reversed configuration, the lock button on the fob successfully unlocks gthe vehicle. Pressing the unlock button does NOT lock the vehicle - essentially it just reversed the issue I was experiencing. So vehicle wiring can be 100% eliminated from the list of suspects. I did proceed to rewire everything according to type A in the manual as per your last reply. I expected this to pop the 15A fuse since I apear to have verified that type C is correct since door lock does function. As expected, the 15A fuse popped. Plugged in a fresh 15A fuse and tried the other button, same results - fuse pops. So as it stands I am pretty much still stuck in the same spot. At least we know for a fact that there is no issue with the vehicle wiring, the trouble has to be somewhere in the 451M or the Viper unit. It would be a doodiety coincidence if both 451M units I purchased were suffering from the same unlock issue. The next step is going to have to wait til the weekend as I will replace the 451M with a pair of 5-pin SPDT relays. This will only solve my problem if the unlock relays happened to be bunk in both 451M units I purchased. If that doesn't work i'm going to beat my head against a wall.