This article was originally published in Danchuk Update 14.3.
PUMP IT UP!!!!
Our Tech Article for this issue of the Danchuk Update answers a question that we get from our customers almost every day. “How hard is it to change over my stock generator to an alternator?” It sounds intimidating, but it really isn’t. With a couple of hand tools and the ability to follow directions you can do the job in an afternoon. We will be using American Autowire conversion harnesses and one of the new Powermaster alternators that look like, and bolt in place of, your original generator. The “PowerGen” alternators make the conversion almost as straight forward as changing out the existing generator, they will work for both V-8 and 6 cylinder applications and it looks stock when you are done to boot. We will also cover the use of a Delco alternator, as this is the most common alternator used in this conversion.
Let’s face it. An alternator that puts out 70 amps or more compared to your 35 amp generator system will charge your battery better, keep your headlights brighter and allow you to run all those neat accessories that generators just don’t have the juice for, like a nice stereo or A/C. So follow along as we show you how easy and clean this conversion can be….
You will need…..
Small Flat Blade screwdriver
Medium Flat Blade screwdriver
1/2” and 9/16” Socket
7/16”, 1/2” AND 9/16” Open End and Box Wrenches
1/4” and 5/16” Allen Wrenches
NOTE: Both the PowerGen and Delco 10SI alternators are internally regulated and this conversion assumes the use of an internally regulated alternator. 55 and 56 are the same and will use a Danchuk #403 (001) wiring harness. 57’s are basically the same as 55-56 with subtle differences. We will highlight those differences in a section for 57 following 55-56. We used a Danchuk #410 (002) wiring harness for our 57 conversion. Also, there are two different lengths of generators that were used on these cars. You will need to use the corresponding length “PowerGen” alternator or change your brackets. If you do not have brackets they are available under Danchuk # 1206 for a 7” bracket and # 1205 for a 6” bracket. The original adjustment bracket is Danchuk # 1299 for the V-8’s. Mounting kits are available under Danchuk # 13533 and 13565. All three years can utilize the Powermaster “PowerGen” alternator using the original generator brackets.
As we mentioned earlier, a conversion that uses the Powermaster “Power Gen” alternator is a bolt in using the existing brackets. For conversions that will utilize a Delco 10SI (Lester 7127) or similar alternator there are a vast number of different brackets depending on your situation. For this article, we are assuming that your classic has the V-8 engine running stock heads. We are using the Bill’s Hot Rod alternator bracket (Danchuk # 12550) as it works with our early pre-69 heads that have no mounting holes in the ends. This bracket uses intake manifold and water pump bolts to attach and makes for a very clean installation. Please note that our car also utilizes an aftermarket manifold and valve covers. This bracket will not work if you are using an intake manifold with the oil filler tube in the front. Our customer service department will be able to recommend an alternate bracket set up if you are using an intake with the filler tube in front and wish to use the Delco 10SI alternator. Also, if your classic has a 6-cylinder engine, you will need to use the Danchuk # 14224 alternator conversion bracket kit if you want to use the Delco 10SI alternator.
For 1955-56 cars….
1) The first step in doing this conversion, or any work on the electrical system for that matter, is to disconnect the negative battery cable from the battery. Lay the cable aside and make sure it cannot contact any terminals on the battery. Now is a good time to check your battery for a full charge. If it is not fully charged put it on the charger. A low battery can cause other parts of the charging system to appear defective.
2) Using your 7/16” open-end wrench, disconnect the brown and blue wires from the generator. (003) Trace the blue wire and one of the brown wires down to the voltage regulator and disconnect them using your medium flat blade screwdriver. (004-005) Next, trace the brown wire through the firewall into the interior under the dash. (006) Follow it until it runs into the generator light socket. Disconnect the brown wire from the generator light socket. There will be two wires on the generator light socket. (007) Follow the remaining wire to the IGN-1 post on the ignition switch and disconnect it from the switch. (008-009)
3) Disconnect the remaining heavy red wire from the voltage regulator and locate the horn relay. Connect the red wire from the voltage regulator to the “B” terminal on the horn relay along with the existing red wire. (010) You will now have two red wires that connect to the “B” terminal of the horn relay. (011)
4) The brown and blue wires can now be removed from the harness, as they are no longer needed. Using a pair of diagonal dikes, snip and remove these wires and tape them off with electrical tape. (011A)
5) Using your 9/16” open end wrench and your 3/8” ratchet and 9/16” socket, remove the original generator from the car. (012-013-014) With your 3/8” ratchet and 3/8” socket remove the voltage regulator from the inner fenderwell. (015)
6) If you are using a Powermaster “Power Gen” alternator install the new alternator in place of the old generator. If you are using a Delco 10SI alternator use your 3/8” ratchet and 9/16” socket to remove the existing brackets for the generator from the exhaust manifold. (016) With your 3/8” ratchet and 1/2” socket remove the generator adjustment bracket. Install your alternator brackets of choice according to the manufacturers recommendation. The Bill’s Hot Rod bracket installation is covered at the end of this article.
Now we can begin to install the #403 conversion wiring harness.
7) Plug the white connector with the brown and red wires into the alternator; the plug is indexed so you can only install it one way. (017-018)) Connect the large 10ga wire with the protective boot to the battery post on the alternator and tighten with your 7/16” open end wrench. Push the protective boot over the terminal. (019)
8) Connect the red wire in the conversion wiring harness to the “B” post on the horn relay. (020-021)
9) Run the remainder of the conversion harness through the firewall and under the dash. (022-023) Remove the original generator light socket from the cluster and plug the new socket in its place. (024)
10) Find the accessory post on the ignition switch. (025-026) There should be one pink wire connected to it and there should be one empty terminal. Plug the remaining wire from the conversion harness onto the extra terminal on the ignition switch. If you do not have an extra terminal on the ignition switch, you will need to use the jumper wire with the pink and brown wires that is provided with the conversion harness. (027) Unplug the pink wire from the switch and plug the pink wire from the switch into the connector on the jumper harness with the pink wire. (028) Then, plug the conversion harness into the remaining connector on the jumper harness (029) and plug the jumper harness into the back of the ignition switch on the accessory post.
11) Check your work to be sure you have no loose connections and reinstall your battery terminal on the battery. That’s it!!!!
For 1957 cars…..
1) See step 1 in 55-56
2) Using your 7/16” open-end wrench, disconnect the brown, blue and black wires from the generator. Trace one of the brown wires and the blue and black wires down to the voltage regulator and disconnect them using your medium flat blade screwdriver. Trace the remaining brown wire on the generator to the bulkhead connector on the firewall and remove it from the bulkhead connector. (030-031) Note: These terminals are designed with a little hook or tang on one side that locks them into the bulkhead connector. Utilizing a small blade screwdriver or pick along the side of the connector may be necessary to pop the connector out. Replace the wire you just removed with the brown wire and spade terminal that comes in the conversion kit. (032)
3) Locate the horn relay. Disconnect the heavy red wire and terminal connector that connects to the horn relay. Replace this wire with the red wire and terminal in the conversion harness. Then, disconnect the other end of the heavy red wire from the voltage regulator.
4) See step 4 in 55-56
5) Remove the heavy black wire and terminal from the voltage regulator. Trace this wire back to the positive terminal on the battery cable and cut the wire loose at the base of the battery cable terminal. Find the red wire in the conversion harness with the loop terminal and fusible link. (033) Connect this wire to the battery terminal you removed the black wire from by removing the battery terminal bolt nut and sliding the loop over the bolt. Reinstall the bolt. You will tighten when you reinstall the battery terminal on the battery post.
6) See step 5 in 55-56
7) See step 6 in 55-56
8) See step 7 in 55-56
Now we move to the underdash portion of this job.
9) Find and remove the brown wire from the bulkhead connector. The procedure is similar to step 2 except this is a female connector that is locked into place by a locking tang on the top. Use a small screwdriver to depress the locking tange that holds it into the connector like you did in step 2. (034-035)
10) Readjust the locking tang so it is sticking up again on the brown wire and insert it into the single female connector on the underdash portion of the conversion harness.
11) Then, plug the bare female terminal with both the brown and brown and white wires in it into the bulkhead connector at the same spot where you removed the original brown wire. (037)
12) Remove the pink wire that connects to the ACC terminal of the ignition switch and plug it into the female socket with the pink wire on the conversion harness. (038) Plug the male connector with the brown and pink wires to the ACC terminal on the back of the ignition switch where you removed the original pink wire. (039)
13) Check your work to be sure you don’t have any loose connections, reinstall your battery cable and that’s it!!!
Installing the Bill’s Hot Rod alternator bracket.
Note: You need to verify that the face of the water pump pulley hub is 5 5/8” from the block to assure everything lines up correctly. We suggest that you verify this dimension BEFORE you begin the installation of this bracket. If it is not correct you will need to adjust the pulley hub on the water pump shaft. This usually means you will have to remove the water pump from the car and use a press to make the adjustment. Before you remove the pump, remember to write down the actual dimension so you can make the proper adjustment to the position of the water pump pulley hub.
You have already removed your generator so all you need do is remove the existing brackets. With your 9/16” socket and 3/8” ratchet remove the bolts holding the brackets to the exhaust manifold. Next, using your 3/8” ratchet and 1/2” socket remove the generator adjusting bracket. Put them aside. (040-041)
1) Out of the box you will see the alternator bracket is fully assembled with all the bolts and spacers in the positions they will be in when the bracket is installed. (042) Make a note of them. Also, when you look at the instructions you will see that there are a couple of spots where proper clearance and spacing is necessary so the bracket aligns properly. Bracket to head spacing has to be 5/8” and the surface of the block to the back of the bracket faceplate needs to be 1 5/16”. Shims are provided with the kit to help you get a proper measurement.
2) Remove the alternator bracket from the assembly and set it aside, keeping the adjusting plate, C –brace and arm together as shown in the photo. (043)
3) Remove the 2 upper water pump bolts and the left front (drivers side) intake manifold bolt.
4) Using the 5/16” Allen wrench install the Adjusting Plate, Arm and C-Brace to the Water Pump using the supplied bolts. Be sure to achieve the required 1 5/16” spacing between the back of the brace and the front of the block. (044-045)
5) Attach the Alternator Bracket to the Adjusting Plate and add enough washers (they are located on the bolt attached to the bracket) to achieve the 5/8” total thickness needed from the manifold gasket surface to the bracket base. (046-047)
6) Mount the alternator to the bracket using the existing bolts and your 5/6” Allen wrench. (048) Make sure the hook on the bottom of the C-Brace is under the alternator. Next, with your 1/4” Allen wrench and the provided bolt, attach the top of the C-Brace to the top of the alternator. (049-050)
7) All there is to do now is install the new belt. Bill’s Hot Rod recommends a Gates 7490 or 7495 as a starting point. See your instruction manual for some tricks if these belts are too long or short.
Click on the photos to see a full sized version.