Under Dash Wiring diagram/schematic

[meanchicken]

Anyone have a good under dash wiring diagram/scehmatic for a 1987 GN?

I need to remove an old and non-functioning alarm system and clean up the wire nest that is currently under my dash, but I don't even want to attempt it without a goo factory wiring diagram/schematic.

Thanks!
Tim

 

[garyk1970]

hey Tim,its not really that hard to remove.....(im understanding this is an aftermarket alarm?).take it one step/wire at a time.

1) disconnect the ground on the battery.
2)find the "brian" unit.
3)unplug all plugs...go ahead.....see pain less..
4)now just trace/follow each lead and disconnect from car....tape/insulate anywhere the wires where tapped into.
5)usually the only wire cut is the starter kill....when you find the connections,cut out alarm wires and reconnect the oem wire back together...


post up any problems or questions.......

 

[turbofrank]

I did as above took about 10 hours and a shopping bag full of wires

 

[azbob]

I also followed the trace and remove plan and it took the better part of a day. Solved several problems I was chasing.

 

[garyk1970]

I did as above took about 10 hours and a shopping bag full of wires

by that being said...the alarm was installed well.......with the average lame install here in Ga, i can find and remove an alarm completely in less than 10 minutes....


my alarm in my car was soldered and taped into the harness after i first removed the dash and harness.....i will never take mine out...

 

[meanchicken]

Did yours look like this?

 

[garyk1970]

looks like an average nut job when you're ready,i can pm my cell ,and walk you through it....i know it looks intimidating,but its not...

 

[meanchicken]

I think it's just the appearance that spooks me.

The starter wire has already been jumped back around the alarm by the previous owner. The alarm kept malfunctioning on him and leaving him stranded, so he hunted out the starter wires and fixed it.

 

[charlief1]

Send me an email Tim. I'll send them to you. All of the under dash diagrams are on my puter but don't want to put them on because of copy right.

 

[garyk1970]

if starter wire is done,all that is left is;
1)siren or horn
2)parking light flash
3)possibly dome light surveillance
4)keyless entry (should only be two wires)
5)shock sensor
6)door switches
7)trunk and hood switches
8)valet switch thats shown in pic...

most wires are not used because alarms are universally designed for all the different automotive harnesses configurations..

 

[meanchicken]

Send me an email Tim. I'll send them to you. All of the under dash diagrams are on my puter but don't want to put them on because of copy right.

Thanks, Charlie.
Just sent you an e-mail.

if starter wire is done,all that is left is;
1)siren or horn
2)parking light flash
3)possibly dome light surveillance
4)keyless entry (should only be two wires)
5)shock sensor
6)door switches
7)trunk and hood switches
8)valet switch thats shown in pic...

most wires are not used because alarms are universally designed for all the different automotive harnesses configurations..

Thanks!
I'll start hacking away next weekend.

 

[charlief1]

Email returned Tim. Hope it helps you.

 

[meanchicken]

OK..got all motivated....pulled the alarm box out....started looking at wires....and went numb.

Whoever did this decided to make it twice as fun and used odd colored wires to jump between the alarm box and the car wiring. I dunno what's what.

I did find a factory connector under the dash that must have been for the factory theft deterrent system. It was not connected to anything.

In one of the pix below, I'm holding the connector that was plugged into the alarm box and you can see an identical connector (the factory one) in the back ground.

For fun, I turned the ignition on to see if the car still starts and runs with the alarm box out...it does.
Other stuff like the siren, shock sensor and the hood switch were already disconnected long ago.

If I understood you right the alarm wiring (other than the starter wires) should only be tapped into the car wiring, and not jumped/interrupted into the wiring ....explains why everything works with the box removed.

Here's some pix.

 

[meanchicken]

I'm making progress.
I'm down to two wires. A yellow one that taps into one of the main power wires under the dash up near the steering column. It's in a tricky spot and will be difficult to wrap once I remove the yellow wire, but I'll get it if I cuss a little.

The other one is this blue wire that taps into a ground wire over near the door jam.

My question is....do these two loose ends of black wire in the pic, need to be connected to each other?

They definitely belong to the car and not to the alarm. The blue alarm wire is soldered to one of them and the other one was already hanging loose with the red terminal attached to it....but they look like the same wire....just severed as part of the alarm install.

 

[garyk1970]

it looks like the lock wire for drivers switch(black)(unlock is lt blue)...looks like it was cut when they tried to tap into it..connect it back together and your drivers lock switch will magically start to work again.

the yellow wire is ign source wire....follow up as far as you can go and tape off. you're doin great....post up a pic of the pile of "crap"...when your done.

 

[charlief1]

Did those diagrams I sent you help at all Tim?

 

[meanchicken]

Did those diagrams I sent you help at all Tim?

Thanks, Charlie.
Yes, absolutley.
They'll come in handy in the future too.

 

[meanchicken]

It's not a tumor!

Nasty ol' alarm system is out finally.

Auto door locks work much better also

The only bummer is that the under dash cover still sags after all those years with that pile of wire and alarm box resting on it.....but it's not as bad as it was.

Here's a pic of the pile of junk I removed. Feels like abut 10 lbs of dead weight.

 

[turbolou]

Reply

Good job Chicken, I have wiring diagrams if needed also. Now you know why I had a heart seizure when I lowered that panel & seen that rats nest.

 

[meanchicken]

Good job Chicken, I have wiring diagrams if needed also. Now you know why I had a heart seizure when I lowered that panel & seen that rats nest.

Thanks Lou.
I was dreading the day when you'd look under the dash on my GN.

I'd had that panel down when I installed the Alky control kit a couple years back and about freaked out when that pile of wire tumbled out.

It's much better now.:biggrin: