911 sc alarm bypass
 

1981 911 sc alarm sets itself even though alarm key is in off position
checked resistance at lock- 5 ohms per spec.
removed alarm control box and jumped the two 61 terminals (blue, red blue wires)
still resets itself.
I have trolled the forums any other ideas ?

This is what I found in my archive regarding bypassing the alarm relay socket. I do not remember the origin of the picture. I guess it is somewhere here from the board.

http://forums.pelicanparts.com/uploa...1376856272.jpg

According to this diagram you also should connect the green (GN) and black/white (SW/WS) wires. Color coding seems to be in German.

I hope it helps.

Otto

Otto Thank you I'll give it a try

Alarm bypass.
 

Here's another one:

http://forums.pelicanparts.com/uploa...1376862754.jpg


Good luck,

Gerry

Exactly as in the circuit I supplied. Terminals 15/87a connect +12V to the DME relay, activating it. Without that, the car will not start/run.

Thanks for confirming, Gerry!

Otto

http://forums.pelicanparts.com/uploa...1376864903.jpg

30-red 61-blu/red 61-blu MK-brow/wht E/A-gray

Hn- red/wht K1-brown/red 31-brown t- brown/yel 15-black/red 87 a and K1 both appear to go to fuel pump relay

Still trying to find the correct jumps to disable/bypass the alarm system in 81 SC.

Tried jumping 61 to 61
tried jumpin 61 to 61 and k1 to 15

anyone have any ideas ?

The jumper where indeed correctly positioned for this type alarm relay. I think the cause of your problem is somewhere outside the alarm relay.

Check if DME (relay) gets its control voltage or perhaps something simple as a fyel pump relay.

Again, if you installed the correct jumpers, the car should run and the alarm circuit is bypassed.

What happens when you turn the ignition switch?

Otto

When jumped, the car starts and runs, after the alarm is turned off.

When the ignition is turned off, the alarm comes back on in a around 1 min.

So basically it works. It's just that the alarm key doesn't function correctly.

I went to your initial post and looked at the resistor values you measured. The value of 5 ohms seems a bit low to me. Measuring resistance between E/A and 31 at the connector, alarm unit removed/disconnected, should give avalue of 2k7 with the switch ON and 5k4 with the alarm switch OFF. These values may have a tolerance of 10%.

If they would have choosen for these low values as you suggest, a bad terminal contact could easily increase the resistance, misleading the alarm unit regarding the position of the switch.

If you really measure a resistance of just a few Ohm and the same in both switch positions, there could be a short in the wiring in the door/body feed through. If there is no change in resistance when switching the alarm relay, a wiring hort and/or a defective alarm switch could be the cause.

So, please check the resistance values as described and report these values. Then we go to the next step.

Otto