[eli346]

I have a 1999 Sts with all sorts of electrical problems going on that i think are related somehow but am not sure what to do or check. When the key is in the On position everything works perfect all gauges, the radio, everything. When I start the car is when the issues start. It starts fine and then the security light comes on and stays on once this happens the radio shuts off and cant be turned back on, the power windows and locks don't work, and the gas gauge drops to E. None of the information shows on the dash except for the average speed all the others are blank. Every once in a while the entire dash will just completely shut off and i have to pull over and turn the car off and back on.
So basically the security light comes on and all these things stop working at once when the car is running. When the car is off everything works perfectly fine. Is there any way all of these things are related?

 

[basscatt]

Re: 1999 Sts Radio, gauges and power windows all stop working, security light on?

I have a 1999 Sts with all sorts of electrical problems going on that i think are related somehow but am not sure what to do or check. When the key is in the On position everything works perfect all gauges, the radio, everything. When I start the car is when the issues start. It starts fine and then the security light comes on and stays on once this happens the radio shuts off and cant be turned back on, the power windows and locks don't work, and the gas gauge drops to E. None of the information shows on the dash except for the average speed all the others are blank. Every once in a while the entire dash will just completely shut off and i have to pull over and turn the car off and back on.
So basically the security light comes on and all these things stop working at once when the car is running. When the car is off everything works perfectly fine. Is there any way all of these things are related?

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start with checking for Diagnostic Trouble Codes -
if you don't know how - go here and read the ENTIRE post -

http://www.cadillacforums.com/forums/cadillac-deville-1985-2005-including-1985/138257-how-pull-codes-dtcs.html

if you have any codes - post them here -
ALONG WITH THEIR DEFINITIONS -

 

[Submariner409]

Re: 1999 Sts Radio, gauges and power windows all stop working, security light on?

............... and have you done anything to the original sound system ??? It is part of the car's content theft, TheftLock and serial data bus systems. Fool with it or do an improper "upgrade" or install and you begin a chain of electrical and electronic problems that never stop.

For starters, if the car "thinks" it is being stolen or tampered with, the fuel injectors shut down - among other things..........

 

[eli346]

Re: 1999 Sts Radio, gauges and power windows all stop working, security light on?

============================
start with checking for Diagnostic Trouble Codes -
if you don't know how - go here and read the ENTIRE post -

http://www.cadillacforums.com/forums/cadillac-deville-1985-2005-including-1985/138257-how-pull-codes-dtcs.html

if you have any codes - post them here -
ALONG WITH THEIR DEFINITIONS -

There were tons of codes as in probably 50 or more... I don't think they've ever really been cleared before and a lot of them were low voltage codes because the car's battery was recently dead. Could i clear all the codes and then the things that are actually wrong should come back?

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............... and have you done anything to the original sound system ??? It is part of the car's content theft, TheftLock and serial data bus systems. Fool with it or do an improper "upgrade" or install and you begin a chain of electrical and electronic problems that never stop.

For starters, if the car "thinks" it is being stolen or tampered with, the fuel injectors shut down - among other things..........

It has the fully stock Bose sound system in it but when it does work it sounds horrendous so i think the head unit is pretty much on it's last leg I'm not sure if that would set off the security or not.

 

[Submariner409]

Go ahead and "Clear all codes" and try to go for a drive. Many codes, if they go to History, will self-clear from the system after 30, 40, 50 or 100 successful start-drive cycles during which the fault did not reappear.

Codes have either a C or H - Current or History - after them, so you should be able to cull out the history ones.