Question on factory alarm - ‘83 model year

[tirwin]

I currently have the air plenum pulled out in the frunk. Trying to track down an issue and wanted to go over all the wiring and grounds.

Here’s my question. What was different about a car that had factory alarm vs one that didn’t have the option?

I’m trying to figure out if my car originally had the factory alarm and it was later disconnected or if there were certain components that were always installed at the factory. I assume dealers could install the alarm option if a customer wanted to add it.

I see my car has an alarm module. Was that always installed or only installed if the car was ordered with it?

Thanks

[rokemester]

If you have a key mounted on the driver side door and a horn mounted under the front suspension pan you more than likely have a factory alarm. There are some good threads on the proper operation of the alarm. If you have a key switch but no key you need to remove the switch and find a good old fashioned locksmith to cut you a key. There’s also some guys on the net who can hook you up.

[tirwin]

There is a key and a horn. I believe that at some point the driver side door was replaced. If memory serves the alarm key in the door was not wired up. If that is true, that is a possible culprit for my problem. I guess I need to figure out if the wiring is there or if it was it left disconnected.

Thanks!

[86 911 Targa]

I have the factory manual if you need help.

Replacing the lock will require some minor body work,
and a new lock from our host.

Not difficult from the wiring standpoint.

My bet is that the wires were cut and taped up.

Are you trying to re-install the alarm?

Best,

Gerry

[tirwin]

Gerry,

No, not trying to replace the alarm.

Here's the history. About a year ago, I had this confounding problem where -- out of nowhere -- something was putting a ground on pin 85 of the FP relay, which kept the car from starting. I finally found the connecting wire that was the source of the problem. That temporarily solved the issue. But the problem was, I didn't know where that ground was coming from. I got busy with other stuff and never got back to it.

A few months ago, a new series of issues popped up out of the blue -- all seemingly at the same time. The sunroof, power mirror and fuel gauge all quit working at the same time (I think but not 100% sure).

Given the previous issue with the FP relay, I decided it was time to do some investigation and see if I had some bigger problem going on. Step one was to remove the fresh air blower stuff so I'd have easier access to the wiring behind the dash. That's when I discovered the alarm module. Never knew it was there!

To further add confusion to the mystery, the PO told me that at some point one of the doors had been replaced. I guess someone backed into the car in a parking lot. PO always thought it was the passenger door but it appears to be driver side. I redid the interior a few years back and it seemed to me the driver door was relatively new. It had what looks like an inventory bar code on it and it just seems newer. Don't think they were using bar codes back in '83. I can't swear 100% but I'm pretty sure I remember that there was no wiring going to the alarm key switch. I thought maybe since it was a replacement that they just used a door that was in stock. So my guess is the wiring to the door key switch is probably disconnected and laying loose somewhere in the door, dash or frunk.

Today I confirmed that the other end of the mystery ground wire is part of the wiring harness for the alarm module. Reading some posts here, I think I understand how to bypass the alarm module so that's my next step -- totally remove it from the system and remove a point of failure.

I'm going to go over the wiring and grounds to look for other lurking problems.

Then I'll move on to the fuel gauge, sunroof and mirror issue -- I don't see any obvious correlation between the 3 issues. Will dig into that mystery next...