Recently replaced glow plugs and glow plug module, all was well for about a week.

Today would not start as usual, after trying about 10 times, with smoke coming out of exhaust on each try, it finally started and ran very rough until it warmed up a little, either it was flooded when it started or the glow plugs are not working, I then drove the car, after the first stop it restarted but the alarm kicked in with horn blowing and lights flashing, found the alarm module on the passenger side lower firewall and unplugged lower plug on alarm module, it then restarted fine several times during the day, without the alarm kicking in, after sitting for 6 hours it was very hard to get it restarted again, unplugged the harness plug going to the glow plugs on the glow plug module and with the key on I measure 12VDC going to each glow plug at the module.

I am original owner of the car so I know it's history.

Any ideas would be greatly appreciated.

Thank you.