Few problems…Battery, Alternator or Alarm?

[Stevo]

Ok – sorry for the long post but there’s been a few things happening with the car recently and I don’t know if they’re related so I’ll mention them all.

 

Sometime in November the missus left the lights on overnight and the battery went flat – I charged the battery up, re-fitted it and the supra started no problem.

 

Firstly

However, from that point onwards the alarm system (Clifford Concept 650) has been acting strange – basically going off randomly without anything seemingly triggering it. I noticed that the usual LED on the dash that indicates the system is armed, no longer comes on as well. I have been locking it with the key when parking up, then when I come to get back in using the key fob to ‘arm’ then ‘disarm’ the system so that the doors open.

 

Secondly

Over the last few months of driving it, the car has occasionally just died whilst in motion – cutting out at slow speeds. This has happened maybe 3-4 times now.

 

Thirdly

Went out to the car this morning and pressed the key fob to arm the alarm (as in first point above). This worked fine but then when I pressed it again to disarm and unlock the doors nothing happened. Tried my spare key fob and that didn’t work either.

So…unlocked the doors manually with the key, got in and tried the ignition but got nothing – zilch! Nothing even clicked or turned over.

 

I’m not particularly technical or mechanically minded but I’m thinking of the battery or alternator perhaps?

 

If the alternator was gammy, does this mean its’ not regulating the battery correctly, which in turn could lead to loss of power occasionally (cutting out) and a low charge on the battery could lead to the alarm system malfunctioning?

 

How do I determine whether the fault lies with the battery or the alternator?

 

Don’t know whether to take it to a garage or an alarm specialist….

 

Help please…!

[Stevo]

Oh - don't know if it'll have any affect on stuff, but forgot to mention its very cold here this morning with quite a bit of ice.

[merckx]

First of all I would check to see if the positive and negative terminals are tight on the battery.

 

To find out if the battery is holding a good charge you just need to try starting it, does the engine turn over quickly and start up like normal or is it very sluggish. A good test for this is on a cold winters morning.

 

Operating the electric window and windscreen wipers when the ignition is on but the engine isn't running is a good indication of battery condition too but the one above is best.

 

I think you would only have problems with the alarm if the battery was in a really drained state as they only take a relatively small current to operate.

 

But all your problems might stem from that time in November when the battery was completely drained.

 

I recall Matt Harwood saying that some alarms are less stable than others when when you deprive them of power.

[Stevo]

Have checked the terminals and they are good and tight.

 

When trying to start it this morning the engine didn't turn over at all (was fine yesterday though). No visible indications of power - i.e. no dash lights coming on, no wipers or windows operating etc.

 

So battery would appear to be not holding a charge. I've got a 40 mile round trip to work each day so it does get a bit of run on a daily basis.

 

Thanks for the info about the alarm - will check with Matt whether this might be the case with my particular model.