Engine won't start (battery ok)

[si macc]

Hi,

I'm having some issues starting our camper (1.6 td jx). Previously I had an issue with charging our leisure battery (main was working fine with no issue starting engine) and I found the issue was down to the split charge relay for the leisure battery so replaced just before we left (with a hef557 30a relay from halfords). We arrived at our destination last night and stopped the engine but was then not able to start again. All the electrics were working (lights, indicators, etc) but the engine wasn't even turning over.

This morning I checked that voltage on the main battery (12.51v) and the leisure battery (11.6v, was previously 4.5v and have used a little) so the alternator is working ok. I could also hear and feel relay 18 clicking on the fuse board and there is a relay clicking by the engine bay (in the little black box at the rear right).

We've just tried swapping the battery over from a diesel that we know works but the same result.

I've checked all the fuses that I can see and all ok.

Any ideas what to check next? I've put back the original split relay and the only other thing I've done is moved the fuse board in and out a few times. I've checked and I can't see anything that has moved or come loose.

Thanks in advance!

Si

[marlinowner]

Most likely to be a bad connection at the starter motor. There will be a thick wire to the starter motor which should have 12v on it all the time, and a thinner wire with a spade connector onto the starter motor solenoid, that should have 12v on it when the ignition key is in starting position. The wire to the solenoid is the prime suspect.

[si macc]

Hi,

Thanks for the reply. Looks like the split relay was a red herring, the ignition cable had come off the starter motor completely. I can see two spade connectors on the motor but not sure which one to put it in? Found a picture of the starter motor from what looks like the t25 manual but it looks back to front from what we have and nervous about connecting it to wrong place.

Thanks,
Si

[marlinowner]

I can't be certain because I don't have a diesel, but usually if there are two spade connectors on the starter motor they are joined together - are they parallel about 1cm apart? If so you can connect to either.

[kevtherev]

This morning I checked that voltage on the main battery (12.51v) and the leisure battery (11.6v, was previously 4.5v and have used a little) so the alternator is working ok.

That's a dead leisure battery right there.
Any battery that is allowed to go that low will never recover.

Volts ------------ Charge
12.66 V ..... 100%
12.35 V ..... 75%
12.10 V ..... 50%
11.95 V ..... 25%
11.70 V ..... 0%