Anyone know factory security system well?

[TDS-94SSEi]

Hey All,

So, I've had some electrical issues with the Bonneville, and one of the latest things I've noticed, is that the "securtiy" light doesn't seem to work anymore. Last I saw it, was while driving, about a block from home, it lit up on the dash, but car continued on as if nothing was amiss. But now at start-up, it no longer lights, and I'm wondering if there is something wrong with the security/alarm, that maybe in impacting other electrical things?

We have had some instances of the alarm going off, an dthe horn going crazy, after unlockikng the door via key fob, and starting the car. And times where the key fob seems to do nothing, then next time it worrks just fine.

Lately, the car has started just shutting off, the last two times upon application of teh brakes, not sure if that was just coincidence, but at a stop light, and stopping in bumper-to-bumper freeway traffic, the brake pedal interrupts the electrical enough that the dash gauges do a sweep, the radio sometimes will even turn off, sometime losing the clock setting, not always.

Needless to say, I have something I need to troubleshoot, and would love to hear any ideas the rest of the forum might be able to share.

I have pulled out interior enough to get to both ground busses, and the looked just fine. Have had battery cable issues in the past, but they still appear to be good, clean and tight.

Womdering if the securtiy system is just another in the list of things to fix, or if it might be part of the problem somehow.

[motopsyco]

sounds like its probably a short or something in your harness.

[myfirstbonnie]

Did you peel back the insulation on the battery cables. They tend to corrode up under there. Also check the ground cables under the ICM and make sure they are clean and tight.

[TDS-94SSEi]

Did you peel back the insulation on the battery cables. They tend to corrode up under there. Also check the ground cables under the ICM and make sure they are clean and tight.

I didn't peel it back very far, but will explore that option next chance I get.
What is the "ICM" you refer to?

[myfirstbonnie]

Ignition control module. look under your coils and you will see a couple grounds held on by a nut or bolt to the block.

[TDS-94SSEi]

Ah, that is what I was guessing, but thought I'd check to be sure. Was not aware of grounding connection there. Thanks!

[imidazol97]

What's the condition of the battery itself? Are the posts solid?

You have a dash voltmeter--does it show low voltage for the alternator/battery system when you have this problem that seems tied to the brake application?

[TDS-94SSEi]

newer battery and cable bolts actually. And I routinely clean the contact points between cables and battery.

No indication on the dash, as the gauges will do their 'sweep' that they do at initial power-up, when whatever the cause is, interrupts the power. Sometimes while driving the gauges will do that even though the engine stays running. And I've had 2 different clusters in the car, behave the same way. But as I sit here, I don't think I have a volts gauge in my cluster, either. Pretty sure it would just be an indicator light.

[TDS-94SSEi]

Update:

So I did look at the cable ends but did not see anything that looked out of the ordinary.

But I finally broke down and went to talk to a shop that specializes in automotive electrical repair. After a nice discussion, I felt that the guy knew what he was talking about, so I took the car to them for troubleshooting.

Their diagnosis was to clean/soak the cable set in some solution to remove corrosion. So I guess I had some but was not able to identify it myself. My battery was borderline, and being several year old, they suggested a new Interstate battery for the car as well.

So A new battery, cables removed and fully cleaned of corrosion (the work order summary stated 'heavy corrosion', so I guess I didn't know what I was looking for), along with a new neg. side cable bolt, and a spacer beetween the positive cables, and absolutely NO issues (electrical related) since. Security system seems to operate as before so far. I have even noticed that the ECC display has not flashed since this work was done. I had a feeling that a lot of my problems were voltage related, but I had expected to need entirely new cables, had no idea that they could be cleaned the way this shop did them. So far, it's like driving a completely different car. What a nice feeling to have faith that the car will stay running. I had 2 instances of it going completely dead while driving it just before I took it to the shop.

Now, about that pesky oil leak. . . .

[TDS-94SSEi]

More update:

While at first everything seemed to be working great, I have noticed that lately the chime when the key is inserted, and the 'security' ligtht in the dash, have been sporadic at best. Cannot really re-create any specific scenarios when I can get either to work with regularity.

But, the car still runs strong, and displays no indication of other lingering electrical issues, most definitely hasn't been going dead on the road, so I'm probably going to live with it as-is unless something gets worse.