“Ebbs and Flows”, “Feast or Famine”,  “Binge and Purge”, or whatever you’d like to call it is okay with me, but the last couple of projects including the S-10′s must’ve either taken their mental toll or enlightened me that there’s a world outside of the garage  because I called it quits on all things mechanical for the Summer. Thankfully Norm has been helping us get our ‘fix’ these last few months with his posts about the ’51.

I really had no intentions of taking on more automotive work, but as you know someone usually comes along and makes it worth your while to start doing again whatever it is that that you used to do. In my case it was in the form of a 4L80E Automatic Transmission in a 4X4 Silverado. Someone else had realized how much of a job these things are soon after they started to attempt the removal process, so I had the vehicle flatbedded to the shop.

The good thing about these types of jobs is that they can be Continue Reading »

General Motors Model 10 SI alternators with integral voltage regulators have been around for over 40 years and are not only much more reliable than the old-fashioned separate voltage regulators and first-generation alternators typically found in ’60s vehicles but they also put out more amperage at lower engine speeds. Eliminating the separate voltage regulator also reduces needles engine compartment clutter. Wiring them up really is simple, but many people have been spooked when, after hooking up their new alternator, the engine continued to run even after the ignition was turned “off.”

Residual current “backflow” out of the No. 1 [R] alternator terminal is the culprit. In production installations, the factory cures the problem by inducing resistance in this circuit, either via the inherent resistance generated by the tell-tale idiot light “GEN” bulb or by a special, calibrated resistance wire in cars with gauges instead of warning lights.

To perform your own custom installation, splice an inline diode into a 12-gauge wire running to the No. 1 [R] terminal. More reliable than a resistor, a diode will allow the current to flow in only one direction (the electronic equivalent of a one-way check valve). Install the diode so the current can flow toward the No 1 terminal. After shut-off the diode prevents any “backflow.” You can use the alternator diode from the early Chryslers or you should be able to get part number 1N1184 from any decent electronic supply for $1+

As for the two other required wires, run a 10-gauge “always hot” wire to the “BAT” stud terminal and a 10-gauge “always hot” wire to the No. 2 [F] terminal adjacent to the No. 1 terminal. (You can just loop the 10 gauge wire from the No. 2 term to the “BAT” stud for a cleaner appearance, but you’ll lose the remote sensing.)

If you’re converting an older vehicle that’s equipped with the typical GM four-wire external voltage regulator and horn relay-style distribution block and want to minimize any rerouting or new wires, the accompanying schematic shows how to adapt the existing wires to work with the integrated alternator. In this case, the existing idiot light or resistance wire provides the necessary backflow protection.

With rarer three-wire voltage regulators, splice the F and No. 2 voltage regulator wires together and run them to the No. 1 alternator teriminal using the previously mentioned diode, and run the No. 2 wire up to the “BAT” terminal.

To sum it up: The No. 2 wire and BAT wire always run to the battery; the No. 1 wire always runs to the ignition. If the ignition won’t shut off, add a diode.

General Motors (non-computer) HEI distributors are a dime a dozen in the salvage yards and nearly as cheap. Conversion is easy. As shown in the schematic, the typical points system uses an inline resistor or resistance wire between the ignition switch and coil [+] terminal to avoid burning out the points. On mid-’60s-up vehicles this is typically a 20-gauge white/multisriped resistance wire installed between the coil and firewall bulkhead master connector. A full 12 volts only during “crank” [start] is provided by a bypass wire running between the starter solenoid “R” and coil [+] terminals. This is typically a 20-gauge yellow wire. The separate coil also requires low-tension and high-tension hookups to the distributor. In order to run properly, an HEI requires a full 12 volts at all times. The 20-gauge resistance wire must be replaced by a 12-gauge wire (pink if it is desired to maintain the factory color code0, hooked up to the HEI cap’s “BAT” terminal. If you don’t want to hassle getting into the bulkhead connector, splice the new wire into the existing 12-gauge pink wires on the instrument panel side of the firewall that run to the ignition terminal and/or fuse box. Discard or tape off the yellow bypass wire and low- and high-tension leads. If so equipped, connect the electric tach wire (20-gauge brown) to the “TACH” terminal. The three-wire connector from the HEI distributor body plugs into the 3-wire inner receptacle on the HEI cap marked “C-, Grnd., B+”.