When running at night(97' Eliminator eagle 502 Procharged, dual batteries only running on one), when I turn on my accessories the guages radically read different. Should I assume that my fuel pressure is also dropping? Or is this just a phenomenon of a lower voltage? I could not run 2 batteries in the "both" position on the switch because second battery was dead. I tried swithching off everything but the running lights, still a big difference. Fuel pressure reading usually 39 lbs. down to 32! On my Ski Nautique I've never seen this. Thanks for any ideas! Has any one else had the same happen.............
Eric

KY, Sound like a bad connection somewhere. Since they are all reading bad , sounds like a bad ground . Had a similar problem with my Formula.
Turn the key on and the volt meters would read 10 volts. Start it and you would get about 11.5 volts.. Check volts at battery , was 13.7...back of ignition switch was 13.7. Turn lights on and oil and temp guages would change. Mine was a bad connection on the hot side , after the ignition switch.
Good luck , those kind of electrical problems can be a pain in the ass.

I agree w/ MOPOWER,,, I would start checking connections ( including grounds ) your loosing something somewhere,,,, not much help I know but somewhere to start. Check battery voltage then get you meter from the battery to the dash guages - and + to see which side your loss is on.

Yep what they said. Pay special attention to the grounds. I have been wrong but I would bet you have a ground problem.

KYElimEagle, I had the same problem on my 97Eagle. Mine was a loose screw holding the wires on the ignition switch. Most likely not the same problem, but you never know. You just have to start taking it apart and testing with a volt meter.
paradigm shift is probably right with grounding being the problem. They are a pain to find though. Good luck!

on my formula, if not mistaken, ground is purple. and there are short purple jumpers making a train from one guage to another, then to the fuse panel. if all guages are reading funny, then it is the main current carrying ground lead heading to the panel or battery. make a long jumper wire with allegator clips. Put it on the battery (-) then place the other end at various points back along the ground circuit, working backwards toward the guages. when you see the jump in the guages back to normal ( while running/idleing in driveway etc) you know that the bad connections ( ie high resistance) is somewhere between the last uneffected test point, and the one you just touched.

what is happening is there is a very high resistance ( just like a coil in a guage) that is "pulling" the voltage up at what is supposted to be the ground level on the guages. therefore the guages are not seeing the full 14V differential to create their signal they were calibrated for. they are seeing 8 or 10V or so and thus the low readings.

you can also do the same thing with a volt meter and check to verify "0" voltage from points on the ground circuit compared to the battery (-) until you see a positive voltage at a certain point. then you know that length of grund circuit has a large resistance in it and it should be between that point and the last "O" V reading you had. again while running with a full 14V and guages and instrument lights on. you need the current running through the wires to find the problem.

good luck.

you may. if the wiring is very complicated, and you just cant find the problem, end up making a new ground jumper from the last guage , or the fuse panel, back to the battery, but add an inline fuse right at the battery so in the event of a wire short, you don't toast something.