OK I have tried to find what I believe to be the source of a bad earth on my 308gt4 instruments without success. The symptom is as follows. With engine powered up oil pressure is only getting up to 5 bar. when I switch on the mian side lights engine pressure goes up to 6 bar. I also noticed that my engine temp guage stopped reaching close to 90 deg but the fans were kicking in. Again when I switch on the side lights the temp guage jumnps to the right closer to where it should be. I get a similar jump on the oil temp guage also. This has got to be a bad earth that is common across all of the guages. I have tried my best with the wiring diagram, anyone else had this experience or suggestions as to where the common earth is for the instrument binnacle guages on a series 2 308gt4 1979! Cheers Tom
Old cars, especially that era Ferraris, have electrical issues and you can bet you have more than one which makes staring at the wiring diagram a waste of time. I'd go with the B'mans replacement fusebox first. Even if you still have a glitch, that will eliminate most/all of the other problem areas (fuses) and you should be able to isolate any bad grounds easier. ken
Hi guys, Thanks for the recommendation, and while I think that my fuseblocks will cure 90% of the major ills with the 308 electrics, it's quite possible that this is a ground issue and my blocks won't help. If it were high resistance circuits in the fuseblocks, I would expect guage readings to drop when other circuits were activated. I could be wrong though....not exactly sure how the guages are wired. We'll know for sure when you install the new blocks, thanks for the order! I would forget trying to find the bad ground....just add another chassis ground someplace to be sure all those guages have a solid ground. Birdman
