Since I have been working on the Black Pearl. I have had to remove the ground strap. Every time I reconnect the thing. Something that wasn't working now works, but not the way it should. the biggest problem. an after market Excalibur alarm system was installed by PO. When I go over bumps the siren was gong off and lights blink. Does this a couple of cycles then goes off until i hit anther bump. keep in mind I drove the car 3,900 miles across country and the alarm never went off once. I cut the horn, but you can hear the relays from the lights blinking when I hit a bump. Where should I start to remove the 3rd party and R/R the factory systems.

 

Charles,
Sounds like you've already started in the right place - by cutting the horn.
Trace that wire back, cut and pull. Cut and pull any related "foreign looking" wire.
Altogether, given your newer tenure with the Black Pearl, it may be a perfect time to pull the CE panel for R&R.
Great to hear you got you TB tension warning sorted out.

 

Thanks Jim, I'll look for those wires. I plan on pulling the panel for a winter project. Wanted to drive it as much as I can before the weather turns.

 

If youkree going to sniff around behind the CE panel it would be helpful to have a good one side by side. If you can find someone with unrelated winter downtime you might be able to borrow theirs.

 

Before you do anything, pull the ground strap from its grounding point and clean the contact patch on the strap and the car. Then, start the investigation on things that work and don't work.

 

As noted above start looking for the foreign looking stuff. There will probably be a daunting looking amount of wiring associated with the aftermarket alarm but don't be put off a lot of it will be only between components of the alarm itself.

As far as connections into the 928s wiring harneses expect to find

+12V always hot
+12V with ignition on
Earth (maybe 2 separate places)
Connections to central lock controller (if the alarm had keyless entry)
Turn signals or parking lights/side marker lights (left and right and possibly power from the indicator or parking light power)
connection to interior light switched earth (Br/Wh) door switches, + hatch switch + bonnet switch.

All the above should be a case of removing and making good the wires.

If the alarm had an immobiliser as well you would expect to find;
1/
Starter - either the ouptut from the starter relay (fat yellow wire) or the trigger voltage to the starter relay (thin yellow wire)

2/
Other immobiser circuit (if there are two) will be to interrupt either EZK, LH or Fuel pump power - again will probably be either output from or trigger voltage to the relay

In 1 and 2 above expect to find the original wiring has been cut and is now connected through the immobiliser part of the alarm. The wiring will probably be black and there may well be two separate wires terminated together for each part of the immobiliser connections.

Chances are these connections will be made at the CE panel plugs so it could be obvious which wires have been cut. I'ld reconnect them using crimp and solder insulated spade connectors, and you may wish to make a note of which ones were cut so you can re-use those cut connections in the future should you install a new immobiliser system.