Thread: Disco Electrical Problem

Got a problem with my 95 Disco 3.9 V8.

Just finished fitting a new radiator and serpentine belt. Had engine running while getting air out of the cooling system and everything was fine although it just stopped once but restarted ok.
Left it for about 15 minutes and decided to take it for a short drive to get it up to operating temp and check for leaks. It started running rough and eventually stopped. Tried restarting and all I got was a click. Checked battery voltage and was down to 12.13v, should still be enough to start it.

Put the battery on charge overnight and checked it this morning and with charger connected was reading 14.6v. Disconnected charger with multimeter still connected and watched the voltage drop rather quickly down to 12.1v.

The battery is an Optima red top less than 12 months old but has not had much regular running. I don’t think I had started it for about 3-4 weeks prior. Alternator was charging fine last time I checked.

Got home from work tonight and checked battery. It is now 12.44v and turned on headlights and spotties and they are normal but still just get a click from the starter with no dimming of lights. The dash lights do though.

I initially just thought it was the battery had gone, but the voltage should be just enough to turn it over, especially since the lights are fine and I can understand it running rough if the efi isn’t getting enough volts, but surely the efi needs less than the headlights and spotties.

Has anyone got any ideas on something I am missing here. Is it possible that I have dislodged something in the radiator changeover process that has caused this ?

I need to get it sorted quickly as I have it booked in for a full rustproofing treatment on Monday and I can’t put that off as I’m heading to Moreton early October and you supposedly shouldn’t drive it on the beach for 3 weeks after the treatment.

The only connection to the starter terminal is the main cable from the battery, but there is a junction further up from this cable which supplies power to the main fuse box that supplies current to the engine management which is why I was wondering about that. Will take it for a drive tomorrow and see what happens.