84 Factory Alarm Drawing Down Battery Overnight
08-15-2008, 02:56 PM
#1
Man of many SIGs
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84 Factory Alarm Drawing Down Battery Overnight
A friends 84s has developed a problem recentlt. It will drain the battery if it sits overnight. I am helping to diagnose the issues and so far this is what I have found.
I hooked up a multimeter (set to read amps) between the disconnected ground cable and the negative battery post. I had him read the amp meter while I pulled fuses. I got no change in the amps when I pulled each fuse ( except a small change when removing the fuse that controls the clock. As expected).
So then I began pulling relays. I pulled the first relay and the amp reading went from .172 down to .022 right away. The relay I pulled was for the factory alarm and it is in slot labeled IV on the 928specialists diagram. It is relay p/n 141.951.253.B While removing it, I had a little trouble getting it out and once it was halfway out it began clicking like crazy and became warm to the touch.
The strange thing to me is that the car will still start and run. Is this normal? I could swear that I have removed this same relay before and the car would not run. Am I right or wrong about this?
The diagram says that this relay or maybe this relay slot is used for the alarm in the 84 only. What is unique about the 84?
Any help or feedback will be greatly appreciated. Thanks in advance.
I hooked up a multimeter (set to read amps) between the disconnected ground cable and the negative battery post. I had him read the amp meter while I pulled fuses. I got no change in the amps when I pulled each fuse ( except a small change when removing the fuse that controls the clock. As expected).
So then I began pulling relays. I pulled the first relay and the amp reading went from .172 down to .022 right away. The relay I pulled was for the factory alarm and it is in slot labeled IV on the 928specialists diagram. It is relay p/n 141.951.253.B While removing it, I had a little trouble getting it out and once it was halfway out it began clicking like crazy and became warm to the touch.
The strange thing to me is that the car will still start and run. Is this normal? I could swear that I have removed this same relay before and the car would not run. Am I right or wrong about this?
The diagram says that this relay or maybe this relay slot is used for the alarm in the 84 only. What is unique about the 84?
Any help or feedback will be greatly appreciated. Thanks in advance.
08-15-2008, 03:54 PM
#2
Electron Wrangler
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The 83 & 84 alarms are a bit different to others before & after.
This relay doesn't do much - it controls the connection of the 61 circuit (the alternator exciter/regulator output circuit) to the alarm module.
In later models there is no relay here - just a direct (61) connection.
The relay is controled by the Z4 output of the Alarm - the fuel pump enable/disable - but it doesn't directly contribute to that circuit.
Once the car starts and the alternator is generating the alarm unit suspends any possibility of the fuel pump being disabling by an alarm event (to avoid the car ever shutting down while driving due to accidental arming of the alarm).
It seems on these models there is an extra (uneeded as far as I can see) level of this with this relay... Not having the relay seems to only affect this lockout mechanism... however if this relay is active when the ignition is off there is probably some other problem that you need to fix (in the alarm).
Alan
This relay doesn't do much - it controls the connection of the 61 circuit (the alternator exciter/regulator output circuit) to the alarm module.
In later models there is no relay here - just a direct (61) connection.
The relay is controled by the Z4 output of the Alarm - the fuel pump enable/disable - but it doesn't directly contribute to that circuit.
Once the car starts and the alternator is generating the alarm unit suspends any possibility of the fuel pump being disabling by an alarm event (to avoid the car ever shutting down while driving due to accidental arming of the alarm).
It seems on these models there is an extra (uneeded as far as I can see) level of this with this relay... Not having the relay seems to only affect this lockout mechanism... however if this relay is active when the ignition is off there is probably some other problem that you need to fix (in the alarm).
Alan