If the ambient temperature is low, the 12 v. starter would be used to start the car. The fact that your IMA battery isn't working correctly might also result in the 12 v. starter being used.
It sounds like the starter motor solenoid might be repeatedly activating. But each time it does, the system voltage drops significantly as indicated by the dimming instrument panel lights. The low voltage might result in the starter solenoid returning to its normal position upon which it activates again, etc., etc. If the 12 v. battery is fully-charged and in good condition, the starter motor itself might be not working in some way causing a large electrical current draw and voltage drop. Or maybe the 12 v. battery is bad and just cannot provide the current required to start the car.
Because this car has been sitting for four years, the 12 v. battery would almost certainly have been bad when you bought the car unless it was replaced recently. But also, as indicated by the P1449 DTC, the IMA battery is also not working within spec. This is typical of an IMA battery that has been unused for such a long period. Its individual cells are almost certainly very unbalanced. You might be able to resurrect the IMA battery by using a custom IMA battery charger/balancer to rebalance the cells. But you might be better off in the long run to have your IMA battery rebuilt. Considering how little you paid for this car, even spending $1000-$1200 to have your IMA battery rebuilt would not make your total expenditure very great.
Other problems with hydraulic clutch and brake systems, the fuel system, etc., can result after long periods of storage, so you may have some other repairs ahead. But if the car is basically in good shape, spending some money to fix it up would still be worthwhile.
It sounds like the starter motor solenoid might be repeatedly activating. But each time it does, the system voltage drops significantly as indicated by the dimming instrument panel lights. The low voltage might result in the starter solenoid returning to its normal position upon which it activates again, etc., etc. If the 12 v. battery is fully-charged and in good condition, the starter motor itself might be not working in some way causing a large electrical current draw and voltage drop. Or maybe the 12 v. battery is bad and just cannot provide the current required to start the car.
Because this car has been sitting for four years, the 12 v. battery would almost certainly have been bad when you bought the car unless it was replaced recently. But also, as indicated by the P1449 DTC, the IMA battery is also not working within spec. This is typical of an IMA battery that has been unused for such a long period. Its individual cells are almost certainly very unbalanced. You might be able to resurrect the IMA battery by using a custom IMA battery charger/balancer to rebalance the cells. But you might be better off in the long run to have your IMA battery rebuilt. Considering how little you paid for this car, even spending $1000-$1200 to have your IMA battery rebuilt would not make your total expenditure very great.
Other problems with hydraulic clutch and brake systems, the fuel system, etc., can result after long periods of storage, so you may have some other repairs ahead. But if the car is basically in good shape, spending some money to fix it up would still be worthwhile.
