trying to fix problem

[MacPepper]

we have just installed a new alternator, and have two wires that are now homeless; they were attached to the old alternator, but we arent quite sure what to do with them now. They touch each other, then attach to the alternator. When they are detached, we have no dashboard lighting and no engine alarm. Are these actually running off the alternator? or just earthing to the alternator? or something totally different?! We are having to do this job ourselves due to finances, and neither of us are sparkys :-)

all help greatly appreciated

[DeepFrz]

A little more detail might help. What terminal were they attached to on the old alternator? What kind of alternator did you remove and what kind did you put in? What type and model is your engine?

[MacPepper]

yeah, sorry about that, not much detail and all........kinda of a result of the fact that we are pretty unsure what we are doing! Hubbie said he'd see if he can find the drawing he made when he disconnected the old alternator (it was a 50amp), and now we have joined on a 12v, 120amp bosch. He's most likely lost his drawing though!

[MacPepper]

and engine is 110hp turbo diesel volvo penta, thx

[scallywag]

MacPepper, No dashlights until the extra wire is attached! What is other wire is attached to the dashlights? Does that whire run to the positive ore negative side of the battery. Usually a set of lights has a fuse. Where is it? What side of the circuit is the fuse on for the cabin lights. My engine alarm went off every time I tried turning on the engine. I found that I miswired the alarm. I hope that helps a little. DeepFrz is correct in asking for more information.
John

[GordMay]

Bosch 120A Alternator:
Diode Trio “D+” terminal on alternator goes to the dash light.
AC Stator “W” terminal on alternator is the tach lead.

[MacPepper]

Ok, bear with me here on the dodgy details, but we have NO clue what we are doing!

On the old alternator, there were two wires joined together and they were attached to the capacitor connection.

On the new alternator, if we attach these two wires to the equivalent connection, sparks fly!

We have tried the wires in several other places, and with many differing results, all really just affecting our general 'dashboard' i.e. we have 1 alarm, 1 volt guage, 1 oil pressure gauge, 1 temp guage, 1 lights for dash, and then all those warning alarm picture/lights that come on. With all the different options for placing these two joined together wires, we can't get the dash to work correctly. It either buggers up one guage and the others seem normal, or buggers them all up, or no alarm.....etc.etc

Your help is soooo appreciated!!!!

[DeepFrz]

MacPepper, I think it's time you bit the bullet and called in a local pro. Probably someone who knows Volvo engine panels. It's pretty difficult to try to help someone who has no idea and can't explain the situation properly. Watch the guy who helps you and get a good marine electrical book to read and you will learn so that you may be able to handle the next problem that comes along. Good luck.

[MacPepper]

oh no, please don't give up on us yet! we can't afford a sparky just at the mo.......in a few weeks we can, but we wanted to be boating before then

[Nauticatarcher]

Is alternator externally or internally regulated, can you post picture of back of alternator

[scallywag]

MacPepper,

Do you have a schematic of the electrical wiring on your boat? If so, try to match the old schematic to the wires from the old alternator. If you do not have a schematic then you should make one for your boat. An electrician would spent hours tracking down where a wire went to find out the wires purpose. If you have a library in your town, find a book on alternators. The pictures helped me find the type of alternator I had and where the wires were to go. I know you have a computer so you could search the makers web site for information on the type of alternator is used on the engine. Some makers supply different alternators and wiring harnesses for the same engine. DeepFrz is not giving up on you, you just need to do a little research on what you have. You need to know specifics about make, model, and year to solve the problem. I spent weeks trying to find out what wire was to go where on a battery selector switch. I even have an electrical schematic for my s/v. I could only see one end and all the ends looked the same. Where they went and what the wires were for helped solve the problem. Capacitors make and break a circuit. When the capacitor discharges current is sent along the wire. My guess is a wire from the tachometer was attached to the capacitor. Since you had two wires attached to the same it muddles my guess on the purpose of the capacitor. A 12 volt system is a collection of circuits that do different things. Your challenge or problem is to determine what circuit those wire belong. If you were out to sea you would be in the same situation trying to determine where those wires were attached. With the constant motion of a boat wires do come unattached and no electricians are around except for you. Do not let the sailing season dictate a shoddy repair job. It costs more to become stuck out at sea because something was not done correctly. A tow back to port is more costly than an electrician if you do not make the right electrical connections. I hope this does not sound like a lecture. I have been given many possible solutions to problems from members on this board. I think DeepFrz is just trying to guide you.
John

[courageous cat]

hello if you had sparks allready it may have blown a fuse . the two wires are hot or grounds so if you put them on a stud that was hot (check with test light or voltage meter) put them two wires to ground . and see if things work.

[MacPepper]

we have lift off!!! It seems to be all working, so thanks to everyone for your help/ideas/inspiration. We have ended up attaching the two wires to the alternator, in what seems to be an 'earthing' connection.......which upon hindsight, does seem to be where they were attached on the old alternator.

We have now got another question though; should an oil pressure engine gauge read anything when the engine is not turned on? i.e. does an engine hold some amount of pressure at all times? Ours reads 60psi when the engine isnt started but the ignition key is turned on, then when it runs, it increases.....up to 80psi. (between 60 - 80 is what the previous owner told us she should read), but we just werent sure if having a 60 reading at standstill seemed right?

thanks again

[courageous cat]

hi, no the guages should read 0 psi when engine is off. What you could try is taking wire off oil presure sender ( don't let it rest on engine )and see if guage return to zero . If not possible bad gauge or wire. IF it dose go to zero then check oil presure sendind unit. ohm meter , one end to the stud or spade where wire came off the other to engine so you get reading through oil presure sender.(meter should be zero )
if there is any reading replace sender.Maybe Gord well chime in here he always tells it better.
PS all checks done with engine turned off.
pat

[DeepFrz]

Check this thread.

http://www.cruisersforum.com/forums/...sting-645.html