8 replies to this topic

[kayteedee]

Hi

When I turn my key to start the car it simply cuts out and loses all power. You can't turn the lights on or anything. It did this a while ago in August and managed to fix the issue by disconnecting the battery for 20 minutes then resyncing the immobiliser etc. It hadn't done it again since then so I hadn't thought about it. More recently it seems to be everytime I start the car, I thought it was a worn earth from the battery so I've replaced that but it hasn't fixed the problem. Does anyone have any suggestions?

[Johnmar]

Hi

When I turn my key to start the car it simply cuts out and loses all power. You can't turn the lights on or anything. It did this a while ago in August and managed to fix the issue by disconnecting the battery for 20 minutes then resyncing the immobiliser etc. It hadn't done it again since then so I hadn't thought about it. More recently it seems to be everytime I start the car, I thought it was a worn earth from the battery so I've replaced that but it hasn't fixed the problem. Does anyone have any suggestions?

 

Did you check the grounding connections (boot (battery), startmotor/engine etc)?

I would work my way back from the boot:

1) What do you measure acros the battery terminals (should be > 12V)

2) what do you measure at the solenoid near the startmotor and its ground (should be >12v when not cranking)

3) what do you measure from the thick brown wire on you fusebox against a good ground (should be > 12v)

4)  (optional) what do you measure at your interior light against a good ground if you open the door or switch on that light.

This will tell you where you have to find things. If 1 through 3 are all >12v, than your power sources are ok (as: there is enough comming towards the fuse box)

if 4 is ok, then that terminal form you fusebox is also OK.
 

Edited by Johnmar, 22 November 2020 - 01:02 PM.

[MacGyver]

Check the positive lead from battery to front of car going under the floor.
Seems you might have a short, mine had this a few years ago where a clip chewed into the cables isolation and made a short with the subframe.

[Quinlan minor]

The symptoms are the same as those of a bad battery connection/earth. Remove and clean the battery terminals and connections with a wire brush, the battery earth to body, too. Make sure the battery is fully charged.

 

If the above does not work, check the connections on the solenoid are clean and secure, too.

Grease all connections after you have put them back on.

 

How old is the battery?

It may be failing under load.

[88JRA]

Hi

When I turn my key to start the car it simply cuts out and loses all power. You can't turn the lights on or anything. It did this a while ago in August and managed to fix the issue by disconnecting the battery for 20 minutes then resyncing the immobiliser etc. It hadn't done it again since then so I hadn't thought about it. More recently it seems to be everytime I start the car, I thought it was a worn earth from the battery so I've replaced that but it hasn't fixed the problem. Does anyone have any suggestions?

[88JRA]

Did you get to the bottom of this? I’m having the same issue and struggling to resolve

[Tornado99]

What about a failing/faulty inertial emergency shut off switch? Do these shut off more than the fuel pump on the injected cars?

[bluedragon]

No, they just cut the fuel off and the car's engine dies. All the rest of the electrical items remain powered if the switch is triggered (as many MPi owners know after hitting a large bump at speed.)

 

 

 

Dave

Edited by bluedragon, 10 April 2021 - 07:06 AM.

[andyapanel]

I would investigate the immobiliser if you are convinced your battery is good. Are your symptoms what you would expect the immobiliser to do if someone tried to steal it?

The fact you regained control after switching off battery power might suggest this.

Can you disconnect the immobiliser and see if that helps? I don't have an MPi, so it may be a daft suggestion.

If not, you need to look at the wiring diagram and go through it bit by bit. 

 

Good luck