Did you fully charge the battery first??? If not then do this first, unless the battery is now so dead it will not hold a full charge. As mentioned even small variances in voltage create issue, Cannot stress enough about the battery condition on these cars!!!
Start here first don't dive in until you know you have a good battery!!! Remember you need and AGM type battery with the correct amper/hour rating!
Always said I would go back to a 6 series
Last edited by 645/333; 12-30-2019 at 07:22 AM.