I cant believe I did this! Need Guru help

[Dirt Nap]

Well I am afraid have made a bad mistake. *!*!
My car is a 87 911 and I knew it had a Alpine alarm but did not realize it may have the factory alarm.
My 87 911 battery was dead so I went to start it with a portable jump start system 450 amp. The problem is that I put the terminals on backwards and I thought it was going to weld it self to the battery. I quickly disconnected it and then connected properly. But when I started the car I could hear a weak alarm horn up front honking while the car was running. It was not the horn on the stearing wheel. So in a panic I hit the alpine alarm button which did nothing and pulled the lights on which killed the motor I assume too much power draw on a dead battery I suppose.
Now the car will not start and it does not have spark. The stock fuses all look good but the alpine alarm 5amp fuse was blown as well as a after market 30amp fuse that I am not sure what it goes to but its wired directly to the battery.
Having done a little research here on Pelican. I unpluged the ECU and checked the voltage with the key on at pin 1,15,16,18,35 and only pin 1 has 12V reading.
With the ECO still unpluged I checked the voltage at the dme relay plug 86pin and get 9.6V.

Has the factory alarm crapped out? I have a key hole on my drivers door but I dont have a key that fits it to turn it on and off. I have had this car for 6 years and never touched the factory alarm.

Thanks in advance for helping out.

[scottb]

This thread might help.

http://forums.rennlist.com/rennforums/showthread.php?t=377178

[Dirt Nap]

Thanks Scott for the link there is some good info there. But the car that they worked on here is a 83 CIS model. He solves his problem by replacing the rev limiter next to the tach but I think my cars rev limiter is in the ECU.
Does anyone have experience with the 84-89 models that use the ECU/DME set up?
I read here that I should have power at the ECU connector with the key on at counting top row left to right pin 1,15,16,18,35 and only pin 1 has 12V reading.
With the ECO still unpluged I checked the voltage at the dme relay plug 86pin and get 9.6V. Does this tell you anything?

Thanks again

[ChrisBennet]

I was working on my '86 once (had the motor and battery out of the car and needed to put up the windows) and I hooked jumper cables up to a battery I had laying around - backwards. Fried the EPROM in the DME (the memory chip) and everything else was fine.
I was told that if I had the motor in it could have damaged the alternator.
-Chris

[Dirt Nap]

Originally Posted by ChrisBennet

I was working on my '86 once (had the motor and battery out of the car and needed to put up the windows) and I hooked jumper cables up to a battery I had laying around - backwards. Fried the EPROM in the DME (the memory chip) and everything else was fine.
I was told that if I had the motor in it could have damaged the alternator.
-Chris

Thanks Chris my car has a aftermarket chip as it has euro pistons and c2 cam...... So maybe I can swap the aftermarket chip for the stock one and see if it will start. If it does then I know thats the problem. But I am worried that it could be the alarm as I dont have power at the ECU except pin 1.

Does anyone know if I unpluged the ECU and checked the voltage with the key on at pin 1,15,16,18,35 and only pin 1 has 12V reading. What does that tell you?
With the ECO still unpluged I checked the voltage at the dme relay plug 86pin and get 9.6V. should this be 12v?

[rick-l]

Originally Posted by Dirt Nap

Does anyone know if I unpluged the ECU and checked the voltage with the key on at pin 1,15,16,18,35 and only pin 1 has 12V reading. What does that tell you?

The half of the DME relay that powers everything with the ignition switch on anded with alarm unit ok is not working. The coil gets power from fuse #8 terminal 15 of the ignition switch instead of the DME relay.

Originally Posted by Dirt Nap

With the ECO still unpluged I checked the voltage at the dme relay plug 86pin and get 9.6V. should this be 12v?

86 is where the relay (that isn't on above) gets 12 volts form the alarm unit so it doesn't sound right. I searched for the alarm 86 87 alarm bypass instructions but couldn't find them.

Perhaps a jumper from pin 1 to 4 on the alarm unit connector is in order, but let some experts weigh in before you do it.

[WPOZZZ]

Did the Alpine alarm have a starter kill?

[Dirt Nap]

Originally Posted by WPOZZZ

Did the Alpine alarm have a starter kill?

WPOZZZ I think it may it is the Alpine model 8040 alarm. The manual indicates on page 20 under additional protection.
Starter Disable
A starter cut relay is provided with the system for additional security. When the system is armed, it will prevent the engine from being started.

The Alpine alarm with the new fuse will lock and unlock the doors. I suppose I could arm it and trip it to see if it works. I guess it could be the Alpine alarm although I am worried about the factory alarm sounding during that initial start up. Any ideas?

[Dirt Nap]

Originally Posted by WPOZZZ

Did the Alpine alarm have a starter kill?

If I disconnected the wiring harness to the alpine alarm would that accomplish anything?

[Dirt Nap]

any electrical gurus out there that have experience helping dummies like me fix this problem?

[rick-l]

Jumper pins 1 to 4 on the factory alarm or apply 12 volts to terminal 86 (isolate the wire to the alarm first) on the DME relay?

[Dirt Nap]

Originally Posted by rick-l

Jumper pins 1 to 4 on the factory alarm or apply 12 volts to terminal 86 (isolate the wire to the alarm first) on the DME relay?

Thx Rick okay is the alarm mounted on the passenger side wall behind all the ac duct work....? This may be tough to get to maybe the wire to term 86 is easier.

apply 12v to Terminal 86 were the DME relay plugs in? So pull the relay and wire straight to it with 12v?
what do you mean isolate the wire to the alarm first.?

[rick-l]

Originally Posted by Dirt Nap

what do you mean isolate the wire to the alarm first.?

Put 12 volts into terminal 86 of the DME relay and not back in the wire that is attached to that terminal.

[Wayne 962]

You may be jumping the gun here, disconnect the battery from the car and charge it offline, and then reconnect it to the car. You want to make sure that the problems you're seeing are caused by the backwards cable issue, and not a dead battery.

-Wayne

[Dirt Nap]

Originally Posted by Wayne at Pelican Parts

You may be jumping the gun here, disconnect the battery from the car and charge it offline, and then reconnect it to the car. You want to make sure that the problems you're seeing are caused by the backwards cable issue, and not a dead battery.

-Wayne

Thanks Wayne but I have charged the battery allready and the starter is singing so I think we are okay with the battery..

[sand_man]

A good thread regarding the factory alarm system and how to disable:
84 carrera wont start
Apologies if you've already seen this one...

[HawgRyder]

I can't believe how many people hook up jumper cables and chargers backwards.
A little bit of prevention would stop this from happening.
Grab one of your significant other's fingernail colour bottles (red if possible) and dab a little on the positive terminal.
Make sure the jumper cables are colour coded.
Also check the output of the charger....I have found some that were wrong or just 2 black ends.
I know this is bolting the gate after the horse left, but it might help the next guy.
The number of unqualified drivers of tow vehicles out there is becoming a real problem and is not going to get any better.
In the old days, owners were more hands-on in many ways, but with the computerized cars of today, most owners just open the hood and stare blankly.
I have seen this on the side of the road almost every day.
Bob

[Dirt Nap]

Originally Posted by sand_man

A good thread regarding the factory alarm system and how to disable:
84 carrera wont start
Apologies if you've already seen this one...

Thanks Sandman I have seem this thread and it looks like promising possiblity to by pass the alarm. I am trying to confirm what Rick suggested. He thought that based on the readings I listed (the key on at counting top row left to right pin 1,15,16,18,35 and only pin 1 has 12V reading. With the ECO still unpluged I checked the voltage at the dme relay plug 86pin and get 9.6V) that it looked like the factory alarm assuming the dme relay was working.
My neighbor tested both the new and old dme relays and said they are both working.
I guess the alarm is on the passenger fender side of the firewall? Is it possible to test the factory alarm without pulling out all the ac ductwork blower stuff and doing the jumper?

[rick-l]

Here is another test you could do if you can't figure out how to isolate the DME relay terminal 86

1. remove DME relay
2. put 12 volts from the battery on terminal 86
3. put ground on terminal 85
4. It should go click
5. between terminals 30 and 87 there should be < .5 ohms with it energized

According to your description above this isn't happening. When this relay pulls in it is supposed to power all those other items.

On the other hand I bet it works just fine.

9.6 volts on terminal 86 should pull it in but????

[Dirt Nap]

Okay I just put a wire on term 86 of the DME relay and pluged it in to the socket. When I connect it to the battery 12v I hear a whirl sound up front either the blower or fuel pump I suppose. Then I turned the key on and she started up--Yaaaah!. But when I turned the key off the car kept running. I assume this has something to do with fact that is still had 12v on 86?
So can I assume at this point my problem is the alarm is not sending 12v to 86 on the relay?
Thx again for the help ev1