Oil pressure lamp is on after i changed oil & filter (wix) in my aar cuda.

I started the car just before the change and all was fine..

No other work was done.

after the change the oil lamp was on for maby 5-10sec before i turned the car off.

I replaced the filter again with a new one and tried to start again.. with no difference..

Any suggestions ?

Always fill the oil filter up (add oil several times until it won't take anymore, be patient while doing that ) before using them
It takes time for the oil pump to fill the filter

I see it's a small block, is filter relocated or at angle? How much oil can you put in filter and install? I have mine relocated vertically so I can completely fill filter and install. Seems light may be on for 5-10 normally to gain pressure after change. No gauge? Any engine noise?

One of the best things I ever did on my 408 small block was relocate filter up front behind bumper attached to rad support with nice stainless lines. No dumping of oil on headers and I can use taller filter and fill filter completely before install, and oil changes so much easier!

I stopped using WIX filters long time ago. No longer highly rated and stopped be produced in USA and I had heard of some internal clogging. Amsoil, Royal Purple, and K&N get high ratings. Not saying you have a clogged filter necessarily just some added info.

Edit: I think I see the filter in it's stock location on 340 with 90 degree adapter. My screen kind of dark. I'd consider relocation! I know you may want stock appearance and I can understand but it's so much better.

Yes filter is in stock position. I filled it half way up when i installed it..

Any more and the oil will drip out because of the angle.

How long before building up the pressure?

Dont want to risk anything..

Before I relocated mine I would sometimes have lifter noise for about 10 seconds and then it would start quickly quieting. I wouldn't feel comfortable any longer than that. Cut that first filter open if you still have it. Take a saws all and cut it right in the middle just for heck of it and make sure you don't have bad batch of WIX. I would. No harm. I doubt it's that but simple enough to check.

At this point, you have to pull the distributor and drive, and prime the pump. Turn the ignition on and see if the light goes out.

Did it make any noise? Any doubts, take the sender out and plug a wet gauge in to see what's really going on. Don't start it until it's right.

Yes, I'm wondering about the noise too. Hasn't said but I feel certain there'd been lifter noise if oil wasn't getting pumped. Like you said, prime with a drill. I'd still cut the previous filter open and see what's inside and yes check the light's operability.

Agree! NEVER do any lube system repairs without putting a mechanical gauge on the system and measuring actual system pressure. Lights and electrical gauges are useless!

I would pull the plugs and crank it until the light goes out. Then put the plugs in and send it

Gus

If you do fill it up all the way it will only drip out a little bit when turned sideways to installed, maybe an ounce or two max
I've owned a bunch of early (pre-1972 ) A body small blocks with that oil filter adapter on them I started out half filling them and saw no oil loss at all when installing them, ended up filling them all the way up to the bottom of the steel adapter and lost a little bit of oil, that loss was worth having instant oil pressure after changing the oil and filters

Did you notice if the filter was pressurized after you shut the engine off? I had a filter clog? when testing the oil system on a 440 on a stand. Primed the pump, no oil flow, squeezed the oil filter and felt like something "popped," all good after that

Oil pressure should come up and light go out in a few seconds. 30 seconds? Not right. Wet gauge. Or stick a new switch in it. Spin the pump with a drill. Don't start or crank it until you find the issue. It's already been run enough, if it really doesn't have pressure.

I have had enough senders go bad to suspect a bad one in your situation.

Also check wiring to sensor, mine frayed and broke, easy check, it’s right by distributor on SB.

The oilfilter had oil in it when i changed it the first time so i think it might be the oil sending unit.

Agreed. You can tell by the load on the priming drive if you have oil pressure or not. You should also be able to see oil flowing around the distributor gear bushing.

Do not replace the sending unit and start the motor to see if the sending unit suddenly took a dump or you may risk engine damage>
It's more effort but the correct and only way to address the issue at this point is as everyone has suggested,
Pull the distributor and oil pump drive. Install a mechanical gauge and run the pump with a priming rod and drill motor. the correct direction is CW. (clockwise)

Yep, you will feel it "grab" and pull the drill down once it gets pressure.

I've had a couple of BB's lose their prime for no good reason. Pull the distributor, intermediate shaft and primed them with the drill. No further issues.

use a multimeter and check the sender as it is now.

He said he only ran it for 5 to 10 seconds. I don't think it had enough time to build up pressure.

Will do, thanks!