Central Locking Problem 190E

[sonic71]

Hi All,
I have recently purchased a K reg 190E with a TOAD alarm already fitted. Have had the car since last November and havent really had any problems (just minor things like rotor arm needed to be replaced). Yesterday when I tried to lock and set the alarm with the remote all that happened was the alarm beeped once and the doors didnt lock, the immobiliser was on only. Since then I have put the alarm into service mode and it wont go back to normal mode.
The main problem though is the central locking doesnt work with the key or the remote when the ignition is turned off, with the ignition turned on the and all the doors shut the remote causes the doors to lock, then they all unlock again. With the ignition on and the front passenger door open the remote locks all the doors and they stay locked, the same applies to the key - all the doors lock and stay locked with the ignition on and the front passenger door open. With all the doors locked and the ignition off the remote doesnt work at all and the key will only open the lock that its used on. I have two door switches on each door one for the interior light and I'm not sure what the other one is for - but its this switch that causes the events on the front passenger door. Its WEIRD.

Sonic

P.S. Sorry for the long post

 

[sonic71]

Something that I have noticed is that the central locking vacuum unit seems not operate with the ignition off also if the lights are left on the buzzer does not work either. Am I right in thinking that there is a connector on the ignition barrel that powers the central locking and the lights buzzer when the ignition is off?

Sonic

 

[Stevie A]

If the strange central locking behaviour started when the alarm / imobiliser went weird then there is your answer. I think the alarm system may be playing havoc with your locking.

 

[sonic71]

Have still been trying to trace the fault, I'm still not certain that the alarm is the problem. It seems that the permanent +12V thats required for the alarm is only on when the ignition is on. I have traced this 12V line to a big terminal block in the drivers footwell, is this supposed to be a permanent +12 on this terminal? The terminal has 2 ground connections, 2 Red connections and 1 yellow (its not in the Haynes manual)

Sonic

 

[Stevie A]

Don't know the answer to last question.. Check all fuses are in place correctly and not fried. If the problem started when your alarm system went weird then it must be the alarm system inhibiting the locking in someway maybe. Check Haynes circuit diagrams and see what's on the central locking circuit.

 

[sonic71]

I have fixed my central locking and alarm problems, although I;m not sure why its working now - hehe.
This is what fixed the fault:
1. What I think is the constant 12V rail was only 12V with the ignition turned on, so I traced the wires from the 12V on the terminal block and found that on one went up to the fuse box (no fuses blown).
2. Fuse 3 has never been fitted, so I fitted it just on the chance something might happen. Sure enough what I thought was constant 12V was now 12V all the time, Toad alarm refitted and everything worked OK - yipee.
3. Started car, fast idle now 1500RPM (weird), let car warm up and idle is 1200RPM (even weirder). Remove fuse 3 from fuse box.
4. Central locking and alarm still working with fuse 3 removed and idle speeds back to normal - yipee.

The only thing I can think that has happened is that the constant 12V comes through a relay which is sticking and applying another 12V has freed it up again. Any thoughts are greatly appreciated.

Sonic

 

[C220GJS]

Sonic; Glad you got your problem sorted out, as you say it may have been a sticking relay, can't see why it would come back on unless that was the case if you did nothing else. What colour was the wire from your alarm to the constant live? On mine ( Toad Pro CL) it's a red wire .
Geo.