is it charging

[gbb]

Just getting my boat out for the first time. My depth finder gave me a low battery warning. It was set at 12.5 volts. I lowered to 12 and still got the alarm. When I got back in I checked and with my meter and the motor running I was getting 12.65 volts. Is this what I should have? I got an 86 90hp Johnson. I'm not sure if its charging right or my new depth finder isn't working correct.

 

[wilde1j]

Re: is it charging

~ 12.7 vdc is the static voltage a charged battery should read. If it's being charged with the engine running, the voltage should be more like 13.5 or more, depending on how many accessories are on. If you had no accessories (depth finder, etc.) running and the voltage was 12.65. it's not charging. Test the rectifier and stator.

 

[gbb]

Re: is it charging

This is the voltage I get with the engine running. I have done alot of cranking the engine and using the pt&t and the battery still keeps the same voltage while running. I would think if it is not charging at all the voltage would drop. How do I test the stator and rectifier?

 

[wilde1j]

Re: is it charging

An OEM shop manual would be a big help now. There should be a pair of yellows from the stator to the rectifier. At idle, you should get at least 18 to 20 VAC, note it's AC, coming to the rectifier. No voltage or a lot less and the rectifier isn't producing AC and/or the wiring has a problem. There are also resistance checks to make and diode checks for the rectifier using the ohms range on your VOM. I don't have the shop manual for your motor so I'm a little light on the specifics for your motor. These are expensive parts, so make sure before you just go out and buy parts.

 

[gbb]

Re: is it charging

I tested and found my rectifier is bad. It is the 35 amp water cooled one. I have a 6 amp air cool from a 1984 90 hp johnson. Can I use this, will it work?

 

[wilde1j]

Re: is it charging

Did you check the stator also? It could be bad as well.

From CDI Electronics:

Check the stator and timer base resistance and DVA output as given below for BOTH banks:
WIRE READ TO RESISTANCE DVA (Connected) DVA (Disconnected)
Brown Brown/Yellow 450-550 150 V + 150 V + (*)
White Purple 35-55 0.6 V + {1988 & newer 100 V + (a)} 0.6 V + (#)
White Blue 35-55 0.6 V + {1988 & newer 100 V + (a)} 0.6 V + (#)
White Green 35-55 0.6 V + {1988 & newer 100 V + (a)} 0.6 V + (#)
White Pink 35-55 0.6 V + {1988 & newer 100 V + (a)} 0.6 V + (#)
(*) This reading can be used to determine if a stator or pack has a problem. For instance, if you have no spark on any cylinder and the
stator?s DVA reading is out of spec ? disconnect the stator wires and recheck the DVA output. If the reading is still out of spec ? the stator
is bad. If the reading is now within spec ? the pack is bad.
(#) This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you have no spark on one
cylinder and the timer base?s DVA reading for that cylinder is low ? disconnect the timer base wires and recheck the DVA output. If the
reading stays low ? the timer base is bad. If the reading is now within spec ? the pack is bad.
(a) Check stator DVA first. Then if timer base DVA is 0.6 - 1.5 V, the pack is faulty. If below 0.6 V or 1.5 - 99 V, the timer base is faulty.

DVA adapter:
http://www.mytoolsforyou.com/automotive-tools/ESI-640.html

 

[gbb]

Re: is it charging

Got 22volts ac from it, my brother is helping me with it, I will give him this info and let him test it. I have an 84 90 hp parts motor so I have another stator if its the same. I was upset when I saw that the rectifiers were different. Do you think the 6 amp would work on my engine? The 35 amp runs $250 on I boats, but you have to pay to play. I bought the 84 90hp for $300,it was a good running engine so I was hoping most parts were interchangeable.

 

[wilde1j]

Re: is it charging

Probably OK (stator) then. Don't think you can use the 6A rectifier.