I measured it as 17mm across the threads. Looking at www.speedycables.com I found an adaptor which was M18 (they dont do an M17) but it is too big.
The search continues
Useful list of manufacturer standards
http://www.thinkauto.com/earlywarning.htm
Thats a useful bit of info and coincidentally I am trying to find out what thread my V6 Duratec's water sender unit is.
I measured it as 17mm across the threads. Looking at www.speedycables.com I found an adaptor which was M18 (they dont do an M17) but it is too big.
The search continues
M17 exists but its not a standard size, so its unlikely to be that.
Its probably 3/8" NPT which has an OD of 0.675" which is 17.1mm
David
Thanks David, I will have another look.
Is there a table of the thread dimensions anywhere? I ordered a 1/8 npt / M18 adaptor but the npt part is far too small at 9mm dia - I was expecting
12mm 
Metrification in the 70's was supposed to simplify all this wasn't it?
NPT sizes are done on the bore sizes of the tube they are designed to be cut on IIRC, all very confusing as they bear no resemblence to the OD of the
thread.
Heres a little chart:
http://www.omega.com/techref/taper-thread.html
Multiply the inches decimals by 25.4 to get mm.
The thread could equally be NPTF which is the fine version of the thread. You also need to check the threads per inch.
Though I am pretty sure it was only NPT that has ever been used for senders.
David
[Edited on 14/1/06 by flak monkey]
I think my blacktop zetec was M18 if that helps....I doubt ford use *that* many different senders.
To get an adapter, I just ordered a blanking plate for the relevant size from Think and drilled and tapped it for the sender I wanted to fit.
[Edited on 14/1/06 by stevebubs]
quote:
Originally posted by stevebubs
I think my blacktop zetec was M18 if that helps....I doubt ford use *that* many different senders.
To get an adapter, I just ordered a blanking plate for the relevant size from Think and drilled and tapped it for the sender I wanted to fit.
