Oil pressure sender testing

[TimJM]

One of the jobs on my project list is to repair the oil pressure gauge that has stopped reading. I am confident that it is the something guage related rather than anything else more sinister as previous owner told me the gauge was working fine until it was removed to be repaired as the water temp had stopped working. Once repaired and refitted the water temp was working but now the oil pressure had stopped reading.

The engine is a 4.5 AJP, no oil warning light (so above 10psi at least), engine oil at correct level and engine sounded healthy.

My initial thoughts are either the sender has developed a fault, the gauge was broken by speedy cables when they repaired the water temp part or the oil feed pipe to the gauge has been damaged/kinked as part of the gauge removal/refit work.

What would be the best way to troubleshoot this as if it is a gauge issue I think speedy cables had a 4 week wait to repair them and I want to be on the road within a month?

Is it possible to attach a mechanical test gauge to the sender/engine to try and pinpoint the problem?

I have seen these on bay but am not sure if I would be able to use/fit it to the AJP:
http://www.ebay.co.uk/itm/SYKES-PICKAVANT-OIL-PRES...

[P S K]

The feed for the gauge is taken from just in front of the pressure switch in the V of the engine underneath the coil packs

There is no sender, just a direct feed to the back of the gauge.