Post valve job charging problems

[MNOBLE]

HI All, I just redid the top end of my 1990 merc 260. The engine ran like a top until i shut it down then tried to restart. batterys were dead. It appears that while working on the head on the port side I must have stepped on the main power lead comming out of the alternator and pulled ot out of its connector and therefore was running solely on battery power. Anyway, i fixed that and got a jump start. But no joy, the system is not charging any more. would running the alternator without a connection on the power lead cause the regulator to burn out. I will go do some voltage tests here shortly and post my findings. <br />Mike

 

[ottawamerc]

Re: Post valve job charging problems

how long were you running the engine for? It really should not have run down the battery that fast! Check for a possible loose connection at the battery or the enginge block/ starter. Try turning on any lights to see if they are bright.<br /><br />Ottawa

 

[MNOBLE]

Re: Post valve job charging problems

Well ottawa, to be totally honest, I pulled the boat to Coneaut lake friday evening which is about 1.5 hours from here it was dark when we arrived. ( we had a slip reserved for the weekend ) I elected to not launch in a strange lake in the dark so we spent the night in the boat at the launch ramp. The refridge and lights we were using in the boat all night were draining from 1 battery and it was pretty much drained by morning. I switched over to the second battery prior to launch and she started fine. IM not sure what the charge status of that second battery was when i put it into service.

 

[ottawamerc]

Re: Post valve job charging problems

You might want to check the neutral saftey switch on the control. I got caught with that once!<br /><br />Ottawa

 

[MNOBLE]

Re: Post valve job charging problems

Well, looks like i have 2.76 volts comming out of the alternator.

 

[MNOBLE]

Re: Post valve job charging problems

Should i see 13-14v on the output if there is a bad regulator?

 

[MNOBLE]

Re: Post valve job charging problems

With the engine off, both batteries fully charged 12.5v. I only see about 2V on the Large alternator wire B+. From what im reading here I believe i should see real close to battery voltage. Is this correct? Or is the battery isolator the cause for the drastic voltage drop? please help im lost here. <br />Thanks Mike

 

[ottawamerc]

Re: Post valve job charging problems

With the engine running you should see at least 14v. I beleive. What happens if you try either battery on the switch? you should have battery voltage at the alternator wire though.<br /><br />Ottawa

 

[MNOBLE]

Re: Post valve job charging problems

ok well, im really lost now. I just disconnected the lead from the alternator to the battery isolator and just connected the orange alternator wire. Started it up and checked the voltage from the alternator + to the alternator - and read between 1 and 2 volts. then checked it to the block same, then to battery - still the same. I then shut the engine down, pulled the orange wire measured it to battery - got nothing measured it to battery + and got 2V. all readings remain the same regardless of which battery is selected. Help. BTW, is it me or are these Seloc manuals useless, unless you nned to start a fire. <br />Mike

 

[MNOBLE]

Re: Post valve job charging problems

Looking on Boatfix.com it says if i check + battery to + alternator i should see only .2V I am showing battery voltage when i do that. Does that look like a shorted alternator?<br /><br />Mike

 

[Dunaruna]

Re: Post valve job charging problems

If you test anything '+' to '+' and get battery voltage you have a major short that could be anywhere inbetween the test leads.

 

[ottawamerc]

Re: Post valve job charging problems

Sounds like a blown fusible link. If you get 12v. across those terminals would indicate that the circuit is open. Check for fuses or possible fusible links.<br /><br />Good luck<br /><br />Ottawa

 

[rattana]

Re: Post valve job charging problems

It sounds like a blown fusible link to me too. You need to use a meter and follow the wiring to locate the open circuit.

 

[rbezdon]

Re: Post valve job charging problems

A common reason for this is that the alternator has to be removed to get the heads off and if the B+ wire was removed with out the ground leads of the batteries disconnected there is a chance the B+ got shorted slightly during the removal process damaging the fuse link. I have senn it happen when you forget to disconnect the battery leads before starting the rest of the top end repair job. (Granted my exoerience was in a car but the smae principle applies to the boat engine).