96 GTS not starting -- any ideas?

[regularsavings]

I wasn't able to drive my GTS for about a week due to rain. When I went to start it up, it almost started, but not quite. After a few attempts it got worse and eventually just started clicking. Definitely seemed like a battery issue. I plugged in the battery tender for 48 hrs and came back and it was fully charged, and all the electronics seemed fine. But when I try to start it, I get nothing -- not even the clicking. I tried to jump it, and that also had no result.

Any ideas what might be wrong, or how I can further diagnose?
Thank you

 

[DrTaco]

battery. Replace and enjoy

 

[Jack B]

Before you pull the battery, test the battery with a load type tester. I would also disconect the battery and apply the charger lead directly to the battery. This will guarantee you do not have a wiring issue. A high resistance connection could have the same symptoms as a bad battery.

 

[regularsavings]

Thanks for the replies. At this point I really don't think it is the battery --

The battery in there now is less than 5 months old and is a Diehard Platinum. When I turn the car on the dash gauge reads 12V; also the battery maintainer says fully charged (12V). Everything like headlights and alarm and dash lights work fine, which is not my prior experience with having a dead battery in this car. It's always made at least some attempt to start when above 6 volts.

I swapped starter relay with a fan relay in case that was burnt, but that didn't do anything.

 

[speedracervr4]

What's the Volts read when cranking?

 

[Fatboy 18]

Have you actually disconnected the battery?

Because the battery was weak when you originally tried to start the car it may have caused a problem with the PCM / immobilised alarm system?

If you disconnect the battery, and earth out the battery connector it should reset. Can you lock and unlock the car with the key fobs?

 

[past ohio]

Check that cables are good and no corrosion ....load test the battery

 

[regularsavings]

Have you actually disconnected the battery?

Because the battery was weak when you originally tried to start the car it may have caused a problem with the PCM / immobilised alarm system?

If you disconnect the battery, and earth out the battery connector it should reset. Can you lock and unlock the car with the key fobs?

Thanks, I have not tried disconnecting it, but I will. I forgot to mention it has an AEM standalone unit and not a stock PCM. I can unlock and lock with the key fob.

 

[DrumrBoy]

Check that cables are good and no corrosion ....load test the battery

THIS. If the late summer humidity or rain has caused that yellow powdery schmutz to infest your terminals, you may have exactly this set of symptoms. Its an easy check and an easy fix if that's what it is.

 

[Fatboy 18]

I don't know anything about AEM units but I'm sure others will chip in

 

[VIPER BAZ UK]

Even with an AEM you still have the OE PCM for the alarm,Imob, windows ect ect..

 

[DrumrBoy]

I run AEMs on both cars and am not familiar with anything that doesn't respond like the factory OEM (system-wise). The only thing I notice that's different is that the AEM often requires a restart when warm to enable the right idle program. Other than that it seems to behave like the OEM PCM.