Generator advice - Now alternator

brianj · Post by **brianj** » Mon Sep 17, 2007 8:21 am

Hi, a plea for help before it goes to the auto electrician. . . My pulley side generator bearing started going no friday. . . I wasnt able to get home before the light came on. . I have replaced the bearings, but the red light wont go off. . I did test the gen and it does turn when current is applied, and i swopped the regulator, so it cant be that. . Any othe ideas what the problem could be before i ship it to the experts. . ?

Chris · Post by **Chris** » Mon Sep 17, 2007 8:30 am

Did you check the voltage coming from the gennie?even though you replaced the reg. it might still not be generating the right voltage.

brianj · Post by **brianj** » Mon Sep 17, 2007 10:23 am

I tested with a circuit tester light no light. . But now i have a multimeter, so will report back on the voltages

Post by **calooker** » Mon Sep 17, 2007 2:03 pm

There are 2 brushes that are accessible from the openings on the genny, if they are too worn down then you need to replace them, they should be about 18 to 22mm long, if they look OK then press them in with your thumb in case they have lost contact, there is one at the top and one at the bottom. The bottom one is a bastard to change with the genny in place as the flat screw retaining the copper cable is at a crap angle. The way to replace that one is to loosen the strap, remove the 4 bolts on the shroud and turn the genny over by hand until you can get to the brush, remove the belt it will make it easier. With the genny disconnected from the regulator it should be putting out about 30V and a max of about 35V at higher rpm, to test do the following connect a wire from DF terminal to the genny body start the motor and take a voltage reading from D+ to the genny body, if that looks ok, then the culprit might be the regulator.
Connect everything up and take a reading at the battery while motor is running it should read about 13 to 14V.

brianj · Post by **brianj** » Mon Sep 17, 2007 2:35 pm

Thanks, good trick to know...

vader · Post by **vader** » Mon Sep 17, 2007 9:18 pm

Yip thanks..

brianj · Post by **brianj** » Tue Sep 18, 2007 7:01 am

looks like its coming out.. I could only get minimal voltage when testing this morning...
this is confusing, because it does turn when voltage is applied across the terminals....
will see what the autolec says.....

brianj · Post by **brianj** » Fri Oct 05, 2007 11:12 am

I have picked up an alternator for R400, with stand, and fan attached...
Hopefully this will solve my problems...

Post by **fig** » Fri Oct 05, 2007 11:43 am

brianj wrote:I have picked up an alternator for R400, with stand, and fan attached...
Hopefully this will solve my problems...

When converting from gen to alt make sure you have the appropriate wiring diagrams handy, as they do not necessarily connect to the regulator in the same way. Also determine whether your alternator has an internal or external regulator.

brianj · Post by **brianj** » Fri Oct 05, 2007 1:26 pm

thanks, it is internally regulated... looks pretty simple

brianj · Post by **brianj** » Sun Oct 07, 2007 12:30 pm

... but doesnt work.... getting really good at this now.. got it out in 10 minutes.. sending it off tomorrow morning..

Dawie · Post by **Dawie** » Mon Oct 08, 2007 1:07 am

Remember an alternator is not self-exciting,it needs a small current from the battery through the warning light in the dashboard.If the warning light is fused or not connected,alt wont charge.

vader · Post by **vader** » Mon Oct 08, 2007 3:17 am

Didn't know that...

brianj · Post by **brianj** » Mon Oct 08, 2007 6:38 am

thanks, light was coming on, so its off to the auto elec today...

brianj · Post by **brianj** » Thu Oct 11, 2007 9:18 pm

so got it back this afternoon... whipped it in in 20 minutes and.. voila! working. put a new belt on for good measure, and it seems to be running smooth.
So will be making a run to work tomorrow for my driving pleasure...
Thanks for all the help and advice...btw I also now have 2 fully operational voltage regulators for sale, as well as a dodgy generator with fan and stand....
Any takers?