dei 520 battery backup

I re sized the pics and hope this works. Starting with pic 1 is the diode box from the 520t with modifications....followed by the PS1250 12v new battery which turned out to be 5ah...added heat shrink tubing over the female spade terminals for extra protection using the harness from the old backup battery end.. 3rd pic we have the cut-out I made under my back seat. The wiring was then extended along the side panel of my car in black looming..where it connects to the diode box in the kick panel. Of course the looming was later pushed down under the interior carpet to be hidden. I had an extra plug from another 520t that I placed at the kick panel so that I can easily disconnect this unit if I must. The wiring used was 14awg. Thanks for looking

Finished my install last week, the 520t doesn't seem to be doing it's job. I got it from amazon and I'm wondering if it has been sitting on the shelf for years. Can any one tell me where to find the manufacture date? I see on the package UPC it has: P/N 520T 7/03 Does that mean it was made in July 2003? What does your say there? Thanks!!

To the best of my knowledge that is the manufacturing date. I ad 3 separate 520s and they all had different numbers/dates. So these ones you buy off Ebay and Amazon have been overstock and sitting on the shelf for years. The only thing I could suggest is buying one brand new from DEI or local shop or doing what I did.  If you have any Q's let me know.

The DEI tech I talked to said there should be an "OK" sticker on it with a date code like 9J meaning january 09 etc, and that the 7/03 on the UPC was just the revision date of the package printing. I didn't have any sticker on my battery, maybe it's so old it's before they started doing the stickers.

Ended up getting a different larger battery, and using it with the 520T. Seemed to work properly. I was on a 2 hour trip, and the alarm went off while I was driving, I hit the disarm, and the siren stopped. I went to check it out later that evening and the alarm didn't seem to respond at all. I disconnected the backup battery, and cut the power to the 520T, and then reconnected/enabled power. This seem to reset somehow and the alarm seemed to respond normally. About 24 hours later the alarm (Viper 5901)was not responding again, completely dead, I tried cutting/enabling power to the unit a few times but it still doesn't seem to respond. Fuse is good. Going to leave it over night and see what happens tomorrow. Hopefully the 5901 brain isn't ruined. Any Ideas? I wish I would have just got the battery powered siren instead of the POS 520T. :(

When I had a 520t hooked up previously I had a similiar issue where I disconnected the power to try and set off the backup battery and it kinda froze the alarm brain. So I disconnected the power all together and it was fine...basicly reset the system.  But I am using the new battery from earlier in my posts and having no problems. The only thing I can think of is you may need to re assign your transmitter to that alarm brain. The fuse may be good but are you actually getting power? Possibly a loose connection between the power source and the alarm. Or you may have a ground wire that came loose or unattached to the chassis. If your alarm went off while driving there might have been a loose connection somewhere and the vibration of the vehicle may have caused it to reconnect and trigger.  I would leave the backup battery out of the equation at this moment and retrace your work, connections and make sure those are correct.  If you used butt connectors tug on the wires and make sure they are tightly crimped and making contact. Hopefully you didn't use t-taps.  Once last thing you can try is make sure the remote battery is fully charged. Maybe take it out and reset the transmitter... and it wouldn't hurt to make sure your antenna is connected and not loose or the cable got crimped or cut somehow.  The only thing I know about the 515r back up siren is they seem to have the same issues as the 520t/. Start with the basics and let me know what happens. Glad to help.

Haven't had a chance to run out and mess with this yet, but I'll answer some of your questions: Fuse good, (and power) I'll check for loose grounds. No butt connectors or t taps. Transmitter fully charged, tried the other one as well, even if the transmitter need to be relearned to the system, i think the alarm should still flash the led at least once when the ignition is turned on/of etc. I'll have to check to see if it is responsive to programming with the valet/led. Since the brain can recall all the settings even after complete power loss, I assume there must be a small backup battery in the unit somewhere? or a reset button like on most electronics, I'll have to try that as well. One weird thing, when I was checking the different voltage going in and out of the 520T, it seemed like it was passing voltage from the battery even though there was a 12v source coming in. And when I disconnected the incoming 12v source, it seemed that the battery was feeding back out 12v input wire with about 6v or so. I assume there is is supposed to be a diode in there to prevent any power from the battery feeding back into the vehicle. Maybe the module is faulty/fried. Are there any other backup battery solutions that people are using? maybe from a different brand of alarm that is more reliable and doesn't have the overcharging issues etc? Thanks again for all your help! I'll report back once I have time to look into this after work :)