Battery/Electrical Problem

[PaulTVR]

Hi All

I have an electrical problem that I would like some help with.


After a year off the road for major restoration, I finally got my Chimaera back on the road recently. I have done over 500 miles trouble free in a couple of weeks, but after not using the car for three days, it would not start and appeared to have a flat battery. I put the battery on charge but the charger indicated it was OK. I checked it with a multi-meter which showed 13.5 volts and connected it to a winch, which I have used to move the car when I was repairing it, and it was able to pull the car with no problem.


I reconnected the battery in the car but again the dash lights come on ( perhaps a bit dim), the pump primes (just!) but it will not turn the engine over. I have checked the obvious connections to the starter motor solenoid and various earth connections.


Then I tried turning on the headlights with the ignition off. The lights come on, though they seem dim, and after a few seconds there was clicking from one of the relays and the dashboard lights dim with each click. I tried removing each relay from the passenger footwell fuse box to find which it was. Having found the one that was clicking (top left as you look into the footwell) I swapped it with another one but it still clicked. This suggests it is not the relay but now I am a little stumped.


I have an alarm/immobiliser and had wondered initially if this was causing a drain on the battery. However, as the battery appears to be fully charged I don't know why it will not turn the engine over now when everything appeared to be fine when I locked the car in the garage three days ago.


All suggestions gratefully received.

Paul

[bobfather]

I'd be looking at the ground (earth) points first. A loose nut is all it takes to make a good battery appear flat. There are several but I'd suggest looking at the first ground where the battery -ve bolts to the chassis

[Penelope Stopit]

As above, use your multimeter to check the chassis and engine earth and if you don't find a fault move on to the positives
By any chance are the battery terminals oxidised where they make contact with the battery lugs?

[Steve_D]

Did you take the body off?
If so, did you leave the earth terminals on the bolt that secures the body to the chassis? If you removed the bolt completely you may not have refitted all of the terminals...one may be touching the bolt but not having sufficient contact to carry a heavy current.

Steve

[PaulTVR]

Thank you all for your help. It turns out that the battery was no good after all. I checked all the earthing points as suggested to no avail so I thought I would just try my daily drive (Mondeo) battery. Immediately dashboard lights lit up more brightly and engine turned over, though not strongly enough to start. So a quick trip to Halfords where the old battery was tested and declared dead, new battery bought and installed and car started instantly.
I guess as the old battery had sat around for a year while I did the restoration, with me occasionally charging it up, it had taken a toll on it and wasn't going to last long.

Many thanks again for your suggestions.

[Steve_D]

Do check that you are now charging at at a decent rate.

Steve