Oil pressure sender wire question

[sammyg2]

My SC has always had good oil pressure, just under 1 bar at idle when hot, pretty close to one bar per 1000 rpm.
Last week it stopped regigstering completely. After the panic settled down I found the problem, the sender wire was damaged about 6" from the sender in a couple places. I'm officially blaming it on the PO, don't ask
Anywho, I spliced in a new section of wire about 4" long using automotive electrical cripling thingies (technical term) and sealed them with electrical tape.
Everything is now fine except at idle when warm the gauge shows less that 1/2 bar. It looks like the gauge is reading about 1/2 bar lower throughout the rpm range than it did before. The oil pressure light does not come on at all when the engine is running but does work when the engine is shut off and the ignition is on.

Could the lower readings be caused by increased resistance from the crimping connections or additional 4" of wire length? does the gauge read lower with increased resistance?
BTW I'm pretty good with mechanical stuff but electrically challenged. TIA.

[Jim Smolka]

If it is like the Carreras, then the gage reads max when the wire is off or the pressure transmitter is failed opened (EE term). Grounding the wire causes the reading to be zero. Since the reading is now 1/2 of what it was, it could be that the new wire has a good connection. Also, make sure that the wire is not shorting out to the car.

[304065]

Extra 4" of wire: not unless you used wire the size of sewing thread.

Crimp-on connectors: Yes. Cut it out and solder a piece of the correct color back in, insulate with heat-shrink. Remember, if you vary the resistance value you vary the needle position. I don't know how you could have continuity and not have a low-resistance connection, but my EE buddies tell me that 99% of the time a circuit fails, it fails at a connection, not in the middle of a wire.

Good luck!