Help! Headlight bulbs keep blowing and Central locking faulty

[John Tyler]

Hi everyone, any help please. Headlight blubs keep blowing. Every few weeks, thought maybe cheap lucas blubs so bought Ostram, they lasted two months. 

Also, central locking will not work most of them time. Same with both keyfobs, both with new batteries. I have to get back in the car, turn ignition back on, then off again by pushing the button, then get out, then it will work. Failing that, i use the key. 

The other week. Immobiliser fault popped up on the dash, and car wouldn't start. I had to walk away from car, wait 10 seconds and then try again. Then it worked.

Ghost in the machine? I'm thinking battery or alternator fault. What do i do please? Any help? Similar problems? Thanks in advance. 

[Tdci-Peter]

5 hours ago, John Tyler said:

I'm thinking battery or alternator fault. What do i do please?

battery is always a good starting point. Either get it tested, or get a cigar lighter mounting volt meter, to monitor the system voltage while running, and prior to starting.

These are very cheep, loads on eBay, but can be inaccurate or unreliable, so I would cross check it with a multimeter before relying on it for expensive decisions.

Expect 14.2 to 14.8 volts while driving with normal load (lights, wipers, fan etc). Heavy loads like de-misters might pull it down a bit. Expect 12.2 to 12.6 volts after standing for a while, before starting.

High voltages (over 14.8v) at odd times would suggest a bad battery, as would low standing voltages. Poor regulation and odd voltages while running would suggest alternator, though the Ford smart charge system can drop the charge voltage down a bit at times. But the voltages above are common to all lead based car batteries, so still apply.

Probably the next likely culprit is a dodgy connector or wire in a main loom somewhere. I hope not, as they can be hard to pin down.