echoffmann 2 #1 Posted April 21, 2014 I have a 1990 520H and when I got it none of the indicator lights or healights worked. I just got all those gremlins figured out and now I have a blinking light NEXT to the oil pressure light. I suspected the pressure sending unit and tiggercl has gotten me the updated number for one but then I noticed there are almost 2 lights for the oil pressure? The one to the right of the words "oil pressure" blinks pre start and while running, the one behind the words only shows up when I press "test" Can anyone confirm the blinking right to the light or how to check the oil sender unit to see if its bad? Since it wasn't working when I bought it I don't know if it's always been on or not. I'm afraid to run it until I know there is good pressure. I changed oil and had to add some after a few minute start up so it must have something to run it through the filter. Photo attached of lights, I cought the blinking on while it was flashing on so you can see the two I'm talking about. Share this post Link to post Share on other sites
Martin 2,130 #2 Posted April 21, 2014 (edited) i don't have a 520, but the 416 i would think uses the same principle for the oil pressure light. it will blink when no oil pressure is present. if you indeed have oil pressure and it still blinks the sender is probably at fault or at least a bad connection between the light and sender. only way to know for sure if you have oil pressure (and decent oil pressure at that) is to temporarily hook up a mechanical pressure gauge to the port the oil sender is at now. your test light switch is telling you the lights and/or panel is working properly. I'm not sure why there is two lights on the oil, the 416 only has one(and no air filter or eng temp). maybe do some searching in the manuals section for 520 related electrical, the demystification manual is an excellent source of info. Edited April 21, 2014 by Martin Share this post Link to post Share on other sites
cleat 4,936 #3 Posted April 21, 2014 Looks like you have a panel for a standard shift and the actual light module for the hydro. Check that all wires are connected properly including the main plug into the light module, the 9 pin going to the motor, and the wire going to the oil pressure switch just over top of the oil filter. Cleat Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,483 #4 Posted April 21, 2014 Here is the detailed wiring diagram for the 1990 520-H The oil pressure switch has 2 functions. With no oil pressure the oil light should come on. When there is oil pressure the oil switch provides a ground for the hourmeter so the clock runs. This was done to prevent the clock from running if the ignition switch happened to be left on with the engine not running. Don't know why you have 2 bulbs there. The oil light flashes on all models when activated. Have never seen a steady on oil light. Garry Share this post Link to post Share on other sites
echoffmann 2 #5 Posted April 21, 2014 Looks like you have a panel for a standard shift and the actual light module for the hydro. Check that all wires are connected properly including the main plug into the light module, the 9 pin going to the motor, and the wire going to the oil pressure switch just over top of the oil filter. Cleat Nice find Cleat, never even noticed that! I've looked at the PDF owners manual but it isn't a detailed drawing to show each dash label. Until you showed me the other panel, I never noticed mine doesn't have a Hydro Temp light (standard like you said). Guessing there might be a wiring difference in the panels and my oil light sender might be fine? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,483 #6 Posted April 21, 2014 Looks like you have a panel for a standard shift and the actual light module for the hydro. Check that all wires are connected properly including the main plug into the light module, the 9 pin going to the motor, and the wire going to the oil pressure switch just over top of the oil filter. Cleat You may have nailed it. These light modules were only used in 1990. 114625 is an 8-light module for the 520-H 116975 is just listed as a 7-light module and probably for the 8-speed. Garry Share this post Link to post Share on other sites
echoffmann 2 #7 Posted April 21, 2014 You may have nailed it. These light modules were only used in 1990. 114625 is an 8-light module for the 520-H 116975 is just listed as a 7-light module and probably for the 8-speed. Garry Looks like the light module behind the dash may be correct and "looks" original. The steering wheel was out of alignment and the roll pin half press in SO...maybe the just the dash shroud was replaced for some reason and isn't correct. Either way, the blinking light on mine, is in the correct spot for the oil pressure on Cleats image. If I'm going to have to take off the flywheel to get at/test the pressure with a gauge, maybe just install a gauge and know what the pressure is instead of a light? Not too concerned about the hours since they may be skewed already if this sender is bad and not activating the ground for the hour meter. So many "ifs"... Share this post Link to post Share on other sites
