wiring on 843 1983

[kent Ind]

I can't get oil pressure-temp. and hydrostatic lights to come on when turning on ignition. Have checked wiring diagram and everything seems to check out. If I turn the key on and take wire from neg. on battery and touch the wire that comes from the light at instrument panel to the post on temp. switch the light will go on. Seems as there is a negative problem somewhere. Temp.and oil are on same light. I have a + wire from voltmeter to temp. oil light to trans. warning light to fuel gauge to hour meter. Then there is a wire from oil and temp. light to both oil and temp. switches. All grounds are ok. I can touch test light from positive post and get it to light by touching the other side to engine or body. They should light when turning key on and go off when engine starts. My question seems to be where does the neg. come from to make them go on when turning the key on? Thanks in advance if anyone who can help. Kent

 

[goodtech]

I cannot remember off the top of my head if those lights should turn on. I believe that do not because those switches are normally open, so unless your engine is overheating, your hydro pressure is too high, and your oil pressure is too low it will not allow the power to run through them to turn the lights on. If you can give me your serial # I can take a look in a manual and let you know for sure. There are so many serial numbers out there and each serail # break is usually a different harness and they are all wired different. Sorry I can't give you a solid answer yet till I can look in a book.

 

[kent Ind]

I cannot remember off the top of my head if those lights should turn on. I believe that do not because those switches are normally open, so unless your engine is overheating, your hydro pressure is too high, and your oil pressure is too low it will not allow the power to run through them to turn the lights on. If you can give me your serial # I can take a look in a manual and let you know for sure. There are so many serial numbers out there and each serail # break is usually a different harness and they are all wired different. Sorry I can't give you a solid answer yet till I can look in a book.

Thanks for the reply. I have a operator's manual and it says they are to turn on when turning the key and then go off after it's running. They did work for a long time and then I noticed they weren't working and decided to check into it. Ser# 5020Mlll86.. I have a copy of the wiring diagram and everything seems to check out at this point. Probably something simple. I ordered the service manual for $60.00 and supposed to get it Tues.. Dont' think it will help with this problem as that's the manual I got the diagram from. It should help on a lot of other things. Thanks again

 

[kent Ind]

Thanks for the reply. I have a operator's manual and it says they are to turn on when turning the key and then go off after it's running. They did work for a long time and then I noticed they weren't working and decided to check into it. Ser# 5020Mlll86.. I have a copy of the wiring diagram and everything seems to check out at this point. Probably something simple. I ordered the service manual for $60.00 and supposed to get it Tues.. Dont' think it will help with this problem as that's the manual I got the diagram from. It should help on a lot of other things. Thanks again

found the trouble. Had to replace the oil sending unit. It acts as the negative switch when the engine starts and has pressure. Hope this helps someone in the future.

 

[ajwgator]

found the trouble. Had to replace the oil sending unit. It acts as the negative switch when the engine starts and has pressure. Hope this helps someone in the future.

Hey kent Ind, & fellow 843 owner. Thanks for the info you sent to my post about my 843. The oil sending unit providing the ground for the gauges is good info too. That seems to be the norm for Perkins engines. My two Massey tractors are that way too. Does your 843 have good connectors down to the left of your seat? The ones that you disconnect when you raise the cab up. Mine have been smashed in the past and I need to find some way of repairing them without have to buy the entire harness. Just wondering.