Donny are you sure you have the right sending unit? The small sending unit is for an idiot light. The large bell shaped unit is for an electric oil pressure gauge. The idiot light is hot all the time when the key is in the run position and the sending unit completes the ground. When the oil pressure builds up the sender breaks the ground and the light goes out. If your sure you have the right sender remove the wire from the sender and put the key in the run position. If the light is still on you have a short in the ground wire. If the light goes out you either have the wrong sender or a defective sender. Just because it's a new part doesn't mean it's a good one. Been there before. LOL Dan -----Original Message----- From: Don Owen [mailto:d4owe9@xxxxxxxxxxx] Sent: Monday, February 21, 2011 2:40 PM To: Mopar Discussion Group Subject: FW: Oil Pressure Light Mystery From: d4owe9@xxxxxxxxxxx To: 1962to1965mopars@xxxxxxxxxx Subject: Oil Pressure Light Mystery Date: Mon, 21 Feb 2011 14:16:06 -0500 OK Fellas: How about this one: For our just breaking-in 426 Street Wedge, we hooked up an oil pressure gauge along with the standard dash warning light. The gauge indicates good pressure, 40-50 PSI, and the motor hasn't seized (yet) so we're convinced we have adequate engine oilling. Meanwhile, the idiot light stays on all the time...does not diminish and go out as oil pressure increases. I think I have tried everything using a test light, changing sending units, isolating and/or re-doing the gauge wire, isolating the circuit board, trying different bulb/socket assemblies, removing our "T" fitting for the gauge and screwing the sender straight in to the block as original, and on and on. Too late if my oil pressure gauge is "lying". We're stumped...any suggestions??? Thanks, Donny, 64 Belvedere ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! 1962 to 1965 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html and http://www.1962to1965mopar.ornocar.com/general_disclaimer.html.