I have a 1992 5.7L Mercruiser. Volt meter typically registers about 14V when running. Last time out meter was at 14V when idleing but went to 16.5V (red zone) when I increased the RPMs past about 2000. I understand that the most likely cause of a high voltage reading is a bad voltage regulator. Before I spend the money to replace it does anyone have advice on testing it or possible other causes?
I have another issue with my temperature gauge. I don't think its related but I guess it could be an electical issue. End of last season the temp ran at about 160 up to about 3000 RPM but when I accelerated past 3000 it rapidlly ran up to 200+ degrees. Temp would drop back to 160 or so when I slowed back to 2500RPMs. I have a new out drive as of last year (hit something recently ) so I'm pretty sure its not the impeller. over the winter I took off the t-stat housing and found a hole between two of the large chambers. A Merc mechanic said that was not normal so I replaced the housing and all hoses (inlcuding new t-stat). Now my temp gauge runs up to to about 150 at idle (its a 140 T-stat) but will then runs very erratic at high RPMs. It will sometimes run up to 200 and back down to 140 in a matter of 2 or 3 seconds. I have checked the risers at full thottle and they are only slightly warm to touch so I do not think the engine is overheating. I suspect its either a bad temp sender in the t-stat housing (i used my old one in the new housing), my temp gauge is bad or I have some other electical problem that is causing the volt meter and temp gauge issue. The temp issue has existed since last year but the high voltage reading just started this week (which is why I suspect they are unrealted).
Any advice from anyone will be appreciated.
I have another issue with my temperature gauge. I don't think its related but I guess it could be an electical issue. End of last season the temp ran at about 160 up to about 3000 RPM but when I accelerated past 3000 it rapidlly ran up to 200+ degrees. Temp would drop back to 160 or so when I slowed back to 2500RPMs. I have a new out drive as of last year (hit something recently ) so I'm pretty sure its not the impeller. over the winter I took off the t-stat housing and found a hole between two of the large chambers. A Merc mechanic said that was not normal so I replaced the housing and all hoses (inlcuding new t-stat). Now my temp gauge runs up to to about 150 at idle (its a 140 T-stat) but will then runs very erratic at high RPMs. It will sometimes run up to 200 and back down to 140 in a matter of 2 or 3 seconds. I have checked the risers at full thottle and they are only slightly warm to touch so I do not think the engine is overheating. I suspect its either a bad temp sender in the t-stat housing (i used my old one in the new housing), my temp gauge is bad or I have some other electical problem that is causing the volt meter and temp gauge issue. The temp issue has existed since last year but the high voltage reading just started this week (which is why I suspect they are unrealted).
Any advice from anyone will be appreciated.
