Engine Doesn't Turn Off When Ignition Switched Off. Any Ideas?

[cooper001 0]

Hi,

 

In the process of getting my 205 1.6 rally car back and legal. Have come across some interesting wiring issues so far and this is another, when i turn the ignition off with engine on it just keeps running. Can remove the key and everything. Have fitted a new ignition barrel as was advised it was normally something in the connections but this has made no difference.

 

Anybody had anything like this before? I just want to know the best place to look next really and am a bit stuck, my technical knowledge isn't the best but i can get something fixed if i know what i'm doing. So i may have missed something quite obvious i guess.

 

Thanks in advance.

[Anthony 1,003]

My guess would be that the wiring has been bodged somewhere and something is back-feeding the ignition circuit, thus powering it when the key is removed.

 

Clearly it could be anything on an extensively modified rally car, but two possibly candidates is the alternator exciter wire being ignition fed with no diode, and the fuel pump being both ignition and relay fed. Easy enough to unplug the exciter wire and see if the problem persists to rule that out as being the cause, otherwise it's time to dig out the multimeter and see which circuit(s) are live with the ignition on but engine off that shouldn't be (eg fuel pump)

[cooper001 0]

Ok thanks i will try and have a look at that stuff this weekend. God i hate electrics!!

[cooper001 0]

Hi, bringing this one backup as have finally had some time to get back to looking through this issue.

 

Have been through the wiring system and apart from whats listed its a standard wiring system, changes to the electrics are an extra loop on horn for co-drivers footrest, the battery is in the back with battery cutoff switch inside and fuel relay has been wired through to the console so we can turn on/off. Apparently that was a problem the previous owner had so some electrical issue there possibly. But this was all installed while the engine was turning on off on key without issue for more than a year while i owned it.

 

I'm thinking that changing relays might be an idea.

 

Any advice on which ones to go for or any other ideas?