Charging problem

[Bilito]

Originally Posted by Dave78Chief

Was the 15-16VDC reading up at the alternator or at the battery itself? Read level at battery. Comparing voltage between alternator BAT terminal and across battery terminals to see if there is a bad connection in between.

The condition of the regulator gives you a indication of potential problems. While it is a pain to check connectors and such, it will be something you need to do. Ensure you check:

Terminals for regulator connector wires

Terminals at Alternator

Connections going back to Ignition switch. Hopefully the harness diagram on pdf page 320 will assist you in finding the connectors listed on pdf page 328. If I remember correctly you replaced the Ignition Switch.

Terminal ends at Starter relay, battery disconnect solinoid, and the battery terminals themselves.

Measure across Battery Disconnect Solinoid (yes, one lead meter lead on each large post). Should be less then 1 volt but new solinoid will be almost 0 volt.

As a stated, the corroded condition of the regulator is telling you there may be other problems hidding in the electric system. A Dremel tool, contact cleaner (radio shack), and electrical tape may become your friends.

A fusible link is nothing more than a short piece of wire that is a smaller gauge than the circuit wire. Idea is that if there is to much current draw it will open up. Because of the smaller gauge, they have a habit of degrading with time due to heat generated from the current. Represented as item 37 on pdf page 320. They typically have a flag (ie: 1/2" x 1") on them listing size.

Dave

The hi reading was at the voltmeter in the cab and also across the battery terminals. I started it tonight to show the wife it worked and I had the instrument lights on so I could see the gauge and when it started they got really bright, did not let it run too long, afraid I might burn something up.
What are the chances the new regulater is defective? I got it at advance auto parts, was thinking to return it and get one at NAPA.

[Dave78Chief]

As far as new regulator being bad I can only say anything is possible however, I would be suprised if they take an electrical item back once it's been used. Normally it's only for replacement. Were you able to check the condition of the wire terminals inside the regulator connector?

Dave

[Bilito]

Originally Posted by Dave78Chief

As far as new regulator being bad I can only say anything is possible however, I would be suprised if they take an electrical item back once it's been used. Normally it's only for replacement. Were you able to check the condition of the wire terminals inside the regulator connector?

Dave

Returned the regulator to advance auto parts and drove to NAPA auto parts
Got a NAPA regulator and a regulator repair harness to connect the regulator for 10 bucks less then Advance charged just for the regulator
Spliced the new harness into my wires connected it and started the motor
Max output now is 14.7 volts Is that acceptable?

When I reved up the motor a little the voltage actually dropped to around 14.5

[Dave78Chief]

That is a little high but could be due to your repeated motor starts (battery drawn down and needs charging back up). Just monitor it for now. You do not want it above 14.8VDC. Normal range is around 13.8 to 14.3. System loads (radios, lights, steps, etc.) affect the voltage. Additionally, some rigs are designed to charge the house battery bank will engine is running so you end up with one large combined chassis/coach battery bank. Others, like my old 78, have a manually operated switch to control connection (AUX Start Relay Control). Still othjers have BIRD devices to do the same thing. Then there are some that simply do not charge the coach battery. You have to figure that out for your application. Point is, you may be charging a larger battery bank then just the chassis battery. The only concern at this level will be risk of boiling the battery dry. Just monitor it.

Just a note: Regulator senses battery voltage, If, there is high resistance between battery and alternator BAT / regulator "A" terminal, then that voltage drop can fool the regulator into thinking the level is lower than it actually is.

Simple test (above 0.2VDC = high resistance) with engine running to check voltage loss due to high resistance.




If the regulator case is not properly grounded, then it can create the high voltage issue also. You can do that simple voltage drop test between the regulator case and "-" lead of the battery to. Same 0.2VDC rule applies there too.

Dave

[Bilito]

Originally Posted by Dave78Chief

That is a little high but could be due to your repeated motor starts (battery drawn down and needs charging back up). Just monitor it for now. You do not want it above 14.8VDC. Normal range is around 13.8 to 14.3. System loads (radios, lights, steps, etc.) affect the voltage. Additionally, some rigs are designed to charge the house battery bank will engine is running so you end up with one large combined chassis/coach battery bank. Others, like my old 78, have a manually operated switch to control connection (AUX Start Relay Control). Still othjers have BIRD devices to do the same thing. Then there are some that simply do not charge the coach battery. You have to figure that out for your application. Point is, you may be charging a larger battery bank then just the chassis battery. The only concern at this level will be risk of boiling the battery dry. Just monitor it.

Just a note: Regulator senses battery voltage, If, there is high resistance between battery and alternator BAT / regulator "A" terminal, then that voltage drop can fool the regulator into thinking the level is lower than it actually is.

Simple test (above 0.2VDC = high resistance) with engine running to check voltage loss due to high resistance.




If the regulator case is not properly grounded, then it can create the high voltage issue also. You can do that simple voltage drop test between the regulator case and "-" lead of the battery to. Same 0.2VDC rule applies there too.

Dave

just did the test between the VR case and the neg batt term, it was .3VDC

Did not do the one on the alt, just cut the crap outa my hand when a piece of wood I was cutting on the table saw flew backwards after the cut and hit my hand.

[Dave78Chief]

Ouch I have them little mishaps from time to time too

0.3 volts is an indication of bad connections. That can create your high voltgae readings. For that ground lead, make sure the NEG battery post cable is grounded to the frame (clean connection). No harm in adding ground straps at a few points between engine and frame.

Dave

[Bilito]

Originally Posted by Dave78Chief

Ouch I have them little mishaps from time to time too

0.3 volts is an indication of bad connections. That can create your high voltgae readings. For that ground lead, make sure the NEG battery post cable is grounded to the frame (clean connection). No harm in adding ground straps at a few points between engine and frame.

Dave

I am learing stuff from you every day and just when I thought I knew almost everything, I was cleaning all the batt connections as I went along, must have missed that one. the ground wire on the VR runs from a mounting bolt to a mounting bolt on the starter relay and then into a wire bundle

[Dave78Chief]

LOL - I know all this is a pain but in truth it is a common problem with RV's. You see the comment "clean the connections" over and over. You are just having the pleasure of not only seeing why they have to be clean (effects) but why they have to be checked periodically. Age and moisture work against us.

Dave