My externally regulated alternator is acting like a one-wire, it doesn't turn on until about 2000rpm. Does anyone know if the #4 regulator terminal has to have 12 volts switched? I get about 1.5 volts at the #4 when I turn on the key. I know there is a resistor in the circuit but don't know if it drops the voltage that much or if it's just so the idiot light will work at low output. Thanks.
Is there someone with a volt meter and a non internal regulator who can disconnect the plug and test the voltage at #4 terminal with the ignition on? Please. Thanks, Al.
Hope this is ok to reply to this old post....with the eng. running you should see 13-14.4 volts at the pin 3 and maybe .2 -.4v below that at pin 4...the voltage from the regulator back to the gen bulb is matched with a similar voltage from the guages behind it...If the gauge fuse is blown, the reg. pin 4 voltage goes through the gen bulb and through the gauges to ground (glows)...if the voltage from the gauges is the same as the one from the regulator..(dark)... The voltage at pin4 at "key on" s/b 5-6v...maybe the wire is grounded or shorted or loose connection at a plug...this voltage excites the field through the regulator at "crank"...If it's to low, the alternator is slow to turn on... I just went through grief with a glowing gen light and good charge voltage at the battery... I had no idea a blown gauge fuse could be the cause...all by gauges were working as they were getting voltage backwards from the regulator pin4 wire...
Bear, Thanks for the reply. I get 14 volts after I rev. to 2000 rpm and then it works like normal. I think I'm not getting enough voltage at the # 4 terminal to turn on the regulator. With the engine not running and the key turned on I get only 1.5 volts at #4 I think it should be close to twelve but I'm not sure. When you say voltage at #4 s/b 5-6 volts is that running or engine stopped key on? Thanks again, Al. PS. I think it's always OK to reply to an old post
Al, That was 5-6 with key on and motor stopped...I have rally gauges and the battery fed for them is tied to the back side of the gen light ...That reading was with the reg. wire plugged in and tested behind the wire at pin 4 or you can test at the condensor plug on the side of the regulator if equiped...eng. run ,it came up to a few tenths less than battery voltage... All those with gauges need to check the gauge fuse if the gen light comes on befor eyou change anything...
