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Author Topic: Overcharging with new alternator  (Read 4970 times)


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Overcharging with new alternator
« on: June 30, 2013, 05:10:47 PM »
I have a marine diesel engine. It's a perkins 4.236 if it matters. I'm replacing an old Delco Remy Alternator 1105423 63A 4G20 12V Neg is printed on the case. According to the delco remy site this should be replaced with model 93097.

On the back of my old alternator are four wires. The pos to battery, the ignition wire on the 1 terminal, the tach on the R terminal and the sensor wire to the +battery on the 2 terminal.

I recieved a WPS alternator from my parts guy.  A sticker on the case shows it is model 7127-3N  12 Volts with serial BT12G4. I have installed this alternator and it bolts on fine, but the batteries are overcharging at 15-16 volts. The wiring on the back of the alternator is a bit different than the old alternator it is replacing.  It has the main pos lug, but It has only two spade terminals at 3 o clock labeled 1R and 2F and a gray wire coming out of the case with a R label. I've tried various wiring configurations with no output except (unregulated overcharging) with the sensor wire on the 1R terminal, the ignition on the 2F terminal, and the tack on the R wire.

I have a few questions.

Is the WPS Alternator truly compatible with my original installation or will I do better with a 93097 model Delco Remy?

Was my original alternator internally regulated?

Is my new WPS alternator internally regulated?

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Overcharging with new alternator
« on: June 30, 2013, 05:10:47 PM »


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Re: Overcharging with new alternator
« Reply #1 on: July 03, 2013, 03:25:15 PM »
Your old unit was a 10Si/Type 116 alternator, which are really common with agricultural and industrial applications. The replacement alternator is the standard 10Si series alternator. Both are internally regulated, and should be 100% compatible with each other. Though it looks like the 1105423 comes standard with a self-exciting (one-wire) regulator.

The main problem I see with your hookup is you have the sense wire on the 1-terminal and ignition on the 2-terminal. This is backwards, ignition should be on 1 and sense should be on 2. Also, the sense wire isn't technically needed unless there is a huge distance between the alternator and the battery. If this hookup doesn't work, then it's very likely your voltage regulator is damaged. We have a replacement 12V, standard hookup regulator, part # D101HD.