viper 7900

i am going to install a viper 7900 on a 98 bmw 328i um does anyone knows how to lower the volts on the remote starter to like 11.5??

Why do you need to drop the voltage?

viper sets there remote starter to 14 volts but my car does not have 14 volts that the alt push out...so when i start the car and when the lights come on it dies so someone said you have to drop the volts down to like 11.5 so when the lights come on the car will stay on

Place the key in the ignition.  Do not turn it on, just put it in the ignition and try to remote start it.  What does it do now?

still the same a place wants 100 to hook up a computer to the viper to lower the volts to 11.5

Try a tach input or manualy alter the programming yourself, I can't see the starter working at that voltage. don't forget to wire the purple acc as ignition 2. I've done loads of E36/E46 and NEVER had a problem. For tach, E46, if ODB ll socket is next to floor lamp, there should be a thin black wire coming out from one of the ends. That's tach, if not go to behind inst. panel also on E36 and use black tach feed from there.  Also take your main power from the battery or the spur up front and use the factory grounds either side of inst panel.

i installed the viper today but did not work i only installed the main wires but i left out the alerm and the door locks. i installed the two red wires and another red wire and two black wires but the remote is not turning on, do i have to programe the remotoe to work with the remote starter? i called tech but they can help me cuz they say someone has to hook up a computer to the viper plus the viper did not come with papers

Find a good shop locally and get them to install it. I do about 3 BMW's a month, there are type specific instructions as to either E36 or E46 and you haven't told us which. You will also need a 556U or equivalent by-pass with a valet key. The locks and window close are the easiest parts of this job. I did an E46 last week, alarm R/S and tracking in 3 hours! On that model virtually everything is around driver's floor area.

i have the bypass and the key but what do you mean e36 or e46???

That settles it if you don't know the difference you're obviously out of your depth. I'm afraid to say any more, just go to a good shop and get it installed professionally.