Viper 790XV and 791XV Harness

I am having a problem that recently started with my Viper 790XV. The remote is not always responding when I press the button. Sometimes to unlock it works and then sometime it does not. The lock always works. I tried reprograming the Unlock but no luck. However, if I reprogram the AUX to unlock, it works most of the time. I checked all antenna connections. Nothing new has been added. So I am assuming something is blown in the Alarm or Remote. I wanted to know if I can get the 791XV and will the harness be the same or do I need to rewire? Any help would be great. Thanks. Patel

Well if it were me...(I've had the same problem) I had the Clifford RS3, and upgraded to the Clifford RS3.5. I would just take out the WHOLE alarms. Make sure you prep the alarm brain good, and make sure you get good solder joints on all of your connections. Sometimes what happens if you use those t-taps or something..they may come loose after a period of time. That is the reason a lot of installers use solder and tape. Hope this helps...~The Rookie~

Rookie of the year that is...

Don't let the smoke out of your equiptment..it doesn't go back in.

I do have the wires soldered. Even though, the general signals going and coming from the remote should not be relying on any of the wires I have connected. If you just power up the alarm with the main power wires alone, the remote should work. Thanks. Patel

No, the harnesses are different between the 790xv (old-style large DEI brain and standard mini relay satellite for the remote start), and the new 791xv (smaller redesigned brain with compact relay module for the remote start). What you are experiencing was a common problem with the 790xv's original 478V remote (thick whitish-colored one). Seems the circuit construction was too flimsey and often resulted in poor contacts. Used to pop them open a do a little repair work, but now don't bother as the replacement 479-family of remotes don't seem to suffer the problem.

Here is my delima. Spend $100 on a new remote or $240 on ebay for the new alarm. I was looking at the wiring. From the documentation, it looks like the wires are the same. I would just need to use the new harness... Please advise as to what is better. Thanks. Patel

If you had the original alarm pro-installed, you can generally get the dealer to replace the 478 remote for free because of the known problem even though DEI's written policy doesn't cover remotes... Up to you want you want to do. The connections needed for the 790xv and 791xv are the same, it's just the harness connectors and pinouts are different between the old and new brains... If you are happy with the original install (neat, sound connections, and hidden), and everything works OK otherwise, why reinvent the wheel because the controller died? FYI - if you are paying more than $75 shipped for the new 479 remotes you're paying too much! Good luck!

You failed to mention what what type and year vehicle it's installed in. Although DEI modules have dual polarity doorlock outputs they are not true ground outs but rather transistorized negative triggers. You can't do multiplexed without relays. Can't do negative trigger in most Hondas's without relays either as they require a true ground signal. I seriously doubt that the problem is the transciever. Prepare your future. It wasn't the lack of stones that killed the stone age.

Good point Big Dog, but he indicated this became a recent problem, and was working OK before so I made the assumption the install was proper. However, those 478 remotes DO, and very frequently so, have the exact symptoms nishalp describes. They weren't redesigned into the 479s just because they were ugly! Good luck nishalp!