External Regulated Alternator to Internal Regulated Alternator? 67 Pontiac anyway to convert ext reg to int? She has been having trouble with them and thought if I could do away with the ext reg I would. Thanks
GM Internally regulated units are broken down into 2 models for our purposes, the 10SI and the 12SI. Both can be used interchangably in most cases, and both use identical hookups. The 10SI is the same physical size as your old alternator. It looks rather simular, except the back is more closed, and the two connectors are horizontal instead of vertical. This unit usually has a steel fan. They are rated from 42 amps to 63 amps as a stock unit. The rating is stamped on the case below the mounting ear. The 12SI is a higher output version found on many mid-80's cars. It is easily identifable by its slightly larger case, and a PLASTIC fan. This unit will usually bolt in wherever a 10SI will fit. This does not look as close to your old alternator, but it does put out 85 amps at full load and has a increased output at idle. Note that many of these units had METRIC mounting holes. Also note that the 12SI's from GM FWD cars look the same, but will not mount as well. Look under the hood of just about any 82-87 GM with a Olds 307 and you'll find one of these. If you want a real wiring diagram, look up one for like a 1976 Cutlass. Hookups Either alternator will bolt in place of your existing unit. You may need to "turn" the case to get the 2 wire connector to be accessable on your specific engine. Assuming you pull the alternator from a junk car, make sure to cut the two prong connector for the regulator from the harness. Otherwise, pick up a connector at the auto parts store. Sometimes you have to buy a harness extender to get it. Kits are available that contain an adapter harness for the alternator plug and the original regulator. I think J C Whitney sells these. Easy Way The battery cable goes to the BAT post on the new alternator. Terminal #1 goes to a switched 12-volt source. A cheap-n-dirty way to accompish this AND to retain operation of the charge light is to run a wire from the #1 terminal of the new alternator to the #4 position of the harness connector on the old external regulator. MAKE SURE TO DISCONNECT THE REGULATOR! Terminal #2 goes to the battery. Easiest hookup is to jump it directly to the BAT terminal of the alternator. This is the easy-but-ugly way to do the conversion. Another Easy Way I found the ultimate and easiest way you can convert your external regulated alternator to an internal model. YEAR ONE sells a plug in conversion kit (Part No. HU30 $13.50). It contains a plug in harness for the external regulator and a plug in adapter from external regulated alternator to an internal regulated alternator. NO WIRES TO CUT. No rocket science involved. Fancy Way OK, you said you wanted to retain the external regulator look. No problem! First, remove the old (or use a spare for practice) regulator from the car. Remove the cover plate. Here's your goal: Jumper terminal F and terminal 3 together. Jumper terminal 2 and terminal 4 toegther. TOP (DOWN) VIEW ---------------------------- | | | | | 10 ga. jumper | | ------------- | | | | | |_ F ___ 2 ___ 3 ___ 4 ____| Latch ----> * * * * |___________| 10 ga. jumper Make sure they do not ground anywhere, or are connected in any way. Make sure to cut the resistors off the back of the regulator! Check and double check that these are the only connections made! On The Alternator Step 1: Remove the wires from the plug connector on the 10/12SI unit. This can be done with a pin or small screwdriver to relase the tab that hold the connectors in the plastic shell. If you want to cheat, just cut the wires off the old connector and replace "splice" for "insert" in steps 2 and 3 below. ;^) Step 2: Remove the wire from the old alternator connector that went to the F terminal. It should (usually?) be BLUE or GREEN. Insert this wire in the new connector so it connects to the #2 terminal of the new alternator. Step 3: Repeat step 2 for the other wire; the wire for the old R terminal goes to the #1 terminal on the 10/12SI unit. This is usually a WHITE wire. You may find that the old terminals are corroded or burned. Now's a darn good time to replace them. Checkout Fire up the car. The alternator should start charging immediately if you've hooked up everything correctly. If it does not, here's my checklist, in order: Connector on the new alternator is secure *AND* making good contact. If you used your old terminals then this is probably the bad point. Check for +12 volts at terminal #2 and BAT with the ignition OFF. Check that the generator light works. Check for +12 at both terminals on the harness with the harness disconnected from the regulator. Email me and I'll try and help. Notes I've done this swap several times. I didn't come up with the fancy way until after I had way to much time on my hands and had nothing else to do. The first way works fine and I use it on my beater cars. The second method works nice for a non-100-point resto vehicle. Heck, it's fooled more than a few guys around here. Disclaimer I have never done this swap on a car with factory guages (amp or volt), but I can't really see any reason WHY that would present a problem. You might want to also consider putting in a heavier wire from the alternator to the battery if you're going to run a 12SI. I cooked my 10ga wire at one point. They make conversions to convert a 12SI to a 120 amp alternator if you really need the juice. Of course, just be careful when doing ANY kind of wiring work in your car. Use common sense; don't splice the BAT wire with lousy crimp connectors - SOLDER THEM! Dirty connections make heat - CLEAN THEM. I've seen really nice cars trashed with bad wiring work, or worse - wiring fires.
here is the link for the adapter ,unless you want to rewire it ,just buy this and a 3 wire alternator and plug it in, life is simple
ummmm...if you buy this kit, you can use the "normal" 3 wire 10SI alternator. If you buy a 1 wire alternator you do NOT need this kit! because there's no where to plug it in on a 1 wire alt.
yeah thats what i meant, thats all he wants is an internal alternator,,i got mixed up with all the talk of one wire ,self exciting ones
disconnect old regulator wires.[clip and tape-and place in loom] Install the 3 wire replacement alternator. re connect the 10 Ga wire to Bat terminal. place a jumper wire from same Bat terminal to #1 terminal in 2 wire plug. then connect #2 terminal in 2 wire plug to ACCESSORY side of ignition switch. thats about it!
Thanks The alt on it right now has two terminals but only one has a wire to it. The bat term has the ten ga wire plus a smaller that two wire tie into from the harness.
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