td5 starter motor am I on the right track?

'm having difficulty when my td5 is stinking hot (used for towing or off the motorway) that I can't start it. It sounds like it has a flat battery turns over slow and doesn't fire.
If I wait let it cool slightly or even open the bonnet for a few mins it spins up like normal and fires up no problem. The earths have been cleaned but it's made no difference. The battery turns the motor over for a while and the car splutters as if it's trying to start. Once it has spluttered once it usually starts if I knock it off activate alarm and immobiliser (might not be related) then deactivated it. It's will spin a few times and then fire

I've read on other posts about the starter motor causing spikes and I'm wondering if this is the case with mine. Any suggestions?

how many miles has it done as some high mileage cars get difficult to start when hot due to low compression, once cooled slightly they fire up fast

69000 miles on a 03

Not too high mileage then. On mine there's a low current wire from the ignition switch that joins the starter via a spade connector. That was getting loose and I wondered why I seemed to have an intermittent starter fault, or maybe an immobiliser fault. Once I'd identified the problem and got the thing cleaned up and crimped a little tighter it was much more reliable.

If the engine turns over slowly when hot and freely when cold, it might be worth giving it a feel with a spanner on the crank pulley bolt, just to see if it turns equally easily hot or cold. Maybe something could be binding when it gets hot and expands. Another possibility is if the alternator is not charging well. The battery warning light comes off a different wire than the terminal that goes to the starter and the battery so all can look well on the dashboard but the battery might not be getting the full 14.5 volts. So the cooling down period isn't about cooling down, it's just giving the battery a little while to recover. This happened to me when my main alternator cable was loose.

Cheers. Will get the multi meter out and see what it's putting out when running

I didn't get chance to get the multi meter on it today. But I did have to tow a caravan again which is classic if I knock it off it won't start again.
Anyway took it to a big bridge and stopped it. Cue wouldn't start off the key, turned over but sounded as my wife put it different.
So bump started it dead easy on the hill, so guessing it's the starter.

Done a load more work on it today and found the positive battery terminal loose.
Anyway used a multi meter, 12.5 volts after leaving it all night with the alarm on.

14.3 volts running so I think that rules out the alternator and battery.

That sounds pretty healthy. So it's starting to look a lot more like a starter problem.

Well it gradually got hard and harder to start so I did the starter motor today
On removing the old one it stank of burnt electrics and was a right old mess. Fitted the recon one and the difference is night and day.
No more cranking for 10 secs and using the throttle. Now it spins loads faster and fires up instantly

Good, glad you got it sorted out. That's one little job done that should last you for a few years.