automate am7 in 2008 toyota corolla s

I have a 2008 Toyota Corolla S.  When purchased the Dealer installed an AutoMate AM7.  Up until about 3 months ago all was working great.  One morning I noticed that the remote wasn't remote starting, unarming/unlocking any doors.  I assumed it was a weak battery and attempted the second remote with the same outcome, nothing!  I then replaced the batteries in both remotes only to find out that wasn't the issue either.  I visited the dealership that installed, and they referred me to a local car audio/video shop that they have since given this business to! (Apparently too many unhappy customers!)  I was there less than 20 minutes and the technician told me I was good to go.  They indicated that there was a loose wire on the antenna mounted to the windshield.  This could have been caused by using my sun-shade.  Since that day I haven't used the sun-shade visor and guess what?!; it happened again.  I attempted to wiggle the wire going into the antenna, no luck.  I then pulled the antenna off the windshield, removed the wire and reinserted, no luck.  I then pryed the cover off the XR Plus antenna looked around a bit, put it back together and tried again, no luck.  I then resorted to the smacking of the XR Plus with a screwdriver, low and behold it seemed to have worked!  I then put the unit back on the windshield and tested, all was good and working.  Apon exiting the vehicle and arming I noticed that it took 2 or 3 times to get it to arm.  I attributed it to me not holding the button on the transmitter long enough.  20 Minutes later, remote start didn't want to work from approximately 100Ft, which has never been a problem before.  It finally worked when I was standing at the car.  Not exactly what I need but none-the-less, hopefully and idicator of what's going on here for someone!  I then went on a short errand only to find the remote not working at all when coming out to the car.  (Less than an hour later)  I tried all the steps from earlier without any luck.  I"m assuming at this point that it's a faulty XR Plus module or possibly the wire going from it to the "brain"?  I'm thinking about purchasing another XR Plus off eBay, will it work or does it require some sort of programming or pairing with my system?  Any help is greatly appreciated! I feel stupid locking and unlocking the doors the old fashioned way!

Thanks

It wont require any programming.  XR, XR+, HF  they'll all work on there.  The XR+ being the "better" of them.   The cable should'nt be the problem.  Unless it's all bundeled up under the dash.  DEI recommends streaching the cable out.  But I dont do it and I've never had a problem.  But I DID have some of those antennas go bad over the years.

Are there any DEI dealers around by you to get an antenna to try it?

There are a couple of DEI installers nearby.  I went yesterday and got a replacement antenna from them for $35.  It was the HF variety.  I plugged it in and left it dangling until I figure out it was the culprit and the issue is solved.  This way I could bring it back if it's not the problem.  Been working for two days now so I'm feeling pretty confident that was the issue and will most likely pull the plastic off the back and affix to windshield tomorrow.  Thanks for the reply!

One additional note... is there any warranty coverage that I might be able to get a refund from DEI or should I just accept the fact that it was a $35 fix?

If you sent it to DEI they would probably replace it for you, free of charge.  But they're not going to refund any of your money.

If it was installed by  an authorized dealer, you have DEI''s lifetime warranty, which should be take care of by that original installing/dealer.  NOT the "new" place that they've switched too.

Crape?  Costomer? Mony?

Are you serious?

DEI is a GREAT company.  Send it back and they'll replace it.  Or send it to me with a SASE (padded) and I'll replace it for you.   Or take a nice scenic drive to North East PA and meet me in person and I'll give you a DEI Snake Pit t-shirt too.

No crape!