my 2005 was exhibiting weird traits tailgate randomly opening sort of stuff and refusing to turn over, i checked the battery and it only showed 10v so dead cell thinks i and replaced it, still no crank though.

i pulled the relay and wired across it to turn the starter which works fine but i don't know what to do next,
any suggestions gratefully received.

The tailgate clicking is a sign off a bad batttery or bad battery connections. Check the battery terminals are clean and tight and check that the negative battery lead going to chassis is clean and tight and the same for the lead going between the engine and chassis.

Have you tried swapping out the Starter Relay with an identical one? Is the relay energizing?

The ground pin of the Starter Relay (pin 85) gets set to ground by the ECM if the ECM is happy that the transmission is in Park or if the Transfer case is in Neutral so you could check if that lead is going to ground.

Also check fuse 28 (15 A) in the PDC near to the Starter Relay.

A common problem is the actuator pin that connects the ignition switch to the starter key barrel has a habit of breaking.

You should feel spring resistance on the ignition key when you turn to Start...if not...this actuator pin has definitely broken.
You can check this actuator by removing the covers around the steering column...two female Torx screws and then remove the smaller Torx screw holding the ignition switch in place...this smaller Torx screw is normally a "security" screw that needs a male Torx with a hole down its center.
You will see now if the actuator is broken...there are lots of posts here on where to by a new one at a good price.

You can start the Jeep by having the key in the ignition to overcome the steering lock and to enable the SKIS security system if fitted: then turn the ignition switch with a small flat screwdriver.

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2002 Export CRD 2.5 Sport

Assuming a good battery but the starter doesn't do anything see:
1. bad ignition switch (not where key goes in) on left side of steering column - viewtopic.php?f=5&t=60575&hilit=ignition+switch&start=20
2. bad actuator pin on key side - viewtopic.php?f=5&t=61233&p=678574&hilit=+brother#p678574
3. shift lever interlock cable - try geodi's fix (sorry don't have link) - Pull the shield off the top of the gear shifter, there are 2 small cables in there; the passenger-side one is the sensor cable, it's not electrical, it's an aircraft wire; the sensor is actually located under the steering wheel. Unhooked, problem solved permanently. I thought of a quick way to test the actuator cable without pulling anything apart on the shifter console - With the engine off and in park, pull back slightly on the shifter to apply tension, and try cranking the engine. If it doesn't go... The cable is the culprit b/c the tolerance (and how much it moves normally) isn't much. The cable is pushed toward the front of the vehicle when the selector is in park, and just shifts backwards slightly when the selector is anywhere else. All you need to do is unclip the end of the cable, and push the end into the sheath until it stops (about 1/4") and tuck it away in there. This won't affect anything else in the operation of your CRD, the shift interlock (that foot-on-brake-to-shift) idiot switch will still be there and functioning... Unless that 2-wire connector happens to "fall out" like it did on mine. Strange how that happens sometimes.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Lots of good suggestions, But just be sure your replacement battery has min of 800 Cold Cranking Amps.

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05 Liberty CRD Sport with Leather 115k
GDE ECO, No EGR, no FCV, (system gone)
Oil Drain plug P/N 090-039
K&N Air Filter, 2nd gen Fuel filter head
NEW Rockers & lifters
Mobil 1 0w-40
Stant 13519 195 deg inline Thermostat.
0 281 002 845 MAP
Etecno GX3123 7v Glow Plugs
Advance Gold 800CCA Battery
Traded it for a Quality VW TDI

thanks for all the advice, it is the actuator pin, it has snapped.
I currently am starting it with a screwdriver until i can get the new bit and fit it.

the removal and refitting doesn't look as though it is as simple as i expected the iron "lockshield" all around the ignition made it seem as though i couldn't remove the barrel, i only took the switch out and left it hanging for now as i didn't have much time but i'm hoping i don't have to drill out the screw holding that big old metal plate in place.

at least i am mobile and don't have to get wet or snowed on keep going under the bonnet to the relay to start it.

Thanks again, i'll post my progress with the replacing.

Look up that Dorman actuator pin PM on the Dorman site as they have a nice install video.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs