Viper 791XV Range Issues

I have a Viper 791XV that I just installed into my 1971 Mustang. The alarm works fine, the problem is that the best range I can get is about a block away, and I have to been near the line of sight of the car. I have the antenna placed in the top middle of my windshield. I tried a fresh battery in the transmitter, but that did not help. I also checked to make sure I had a strong 12 volts at the alarm fuse, which I do. I purchased the alarm on Ebay and installed it myself, so warranty work is not an option (unless there's some way around that). So my main question is which part is most likely limiting my range-- the transmitter, antenna, or the alarm brain, and is there any way to test it without buying new parts? Any help is greatly welcomed.

The actual range of the DEI 2-ways is a lot less than the published 1/4 mile. What you are getting is fairly normal. Things that can decrease the range - a bad ground, and coiling up the excess antenna cable. The extra cable needs to be spread out.

I have checked my ground and spread out the antenna cable as much as possible, but neither made a difference. I read in a post on this forum that it's possible to hook the antenna leads up to either an amplified antenna or a CB booster amplifier. Will one of these methods work on the 791XV? (I understand that these methods will not boost the remote to alarm transmission range) If so, which wires will I use? The antenna has a red, black, green, and blue wire going to it.

i wouldnt do that with any of todays remotes.  unless it is a pager with a paging system designed for that purpose.  in a clear area i get the stated range with my clifford 3.5 (same thing), but i can be 20ft away trying to remote start it through one of the heavy fire doors at work and i get no signal.  i think the new LED remotes are supposed to be better on range, they use HF2+ or something new and the antenna looks like a sat. radio antenna (like the really small roadie 2 antenna).MECP certified installer

the new ones use the same antenna as the Valet 554R... one long block in the city is about average for these units....if you measure that distance you'll be surprised how far it really is.... at least our blocks long here are about 1000 ft, which is darned near what DEI claims it will do....Kevin Gerry

Certified Electronics Technician

MECP First Class Installer

Owner/Installer

Classic Car Audio

since 1979