Electrical short falls for 70-83

  1. First Iíll deal with the 240 because that has the most problems. The first shortfall is a minor design flaw in the fuse block. This causes the 3rd fuse down on the right hand side to melt down. We can cure that problem and fix the fuse block as well, but itís a two fold fix. We do a minor modification to the fuse block itself, and then install a plugíníplay relay kit to the dash and tail light circuit. This not only relieves all the pressure from the fuse block but it also saves wear and tear on the headlight switch because it no longer runs all the current through the switch.

  2. The second electrical deficiency is the headlight system. There is approximately a 3 volt drop from the battery to the headlights, and all the power is run through the headlight and high beam switches. This shortens their life expectancy considerably. We now sell a headlight relay kit for the 240ís that is also a plugíníplay kit. This kit allows the switches to only be used for the triggering side of the system and it no longer runs all the heavy draw current through them. This takes all the strain off of those switches as well.

  3. Behind the fuse block and just to the right there are 2 inline fuse holders. They are accessed from the passenger side (for LH drive cars) right by the passengers left knee. They are used for the rear defroster and the heater fan. The holders are on a very short pigtail and itís almost impossible to change the fuse in them. The fuse holders are also under rated for the 20 amp circuits that they are on. Itís only a 10 amp fuse holder and weíve seen plenty of them melt down through the years. We sell a 35 amp rated fuse holder with a longer pigtail that needs to be spliced in to both of these circuits, thereby replacing both original fuse holders. With the longer pigtail they will be much easier to change fuses if needed. Of course you need to install the 20 amp fuses into the 35 amp rated holders.

  4. Is the alternator output, especially at idle. On the 70-74 cars the alternator output at idle is only 15 amps. On the 75-83 cars itís only approximately 20 amps. Thatís fine if you never use any accessories, but turn on those accessories and itís very common to have a discharge at idle. The common scenarios when you come to a stop are: Wipers slow down a lot, turn signal speed slows down, heater fan slows down, and your headlights dim. This is called a brown out effect. Rev the engine up a little and these problems diminish. These problems are more noticeable on the 70-74 cars but this shows up on all of them. All of the 4 cylinder vehicles through the 60ís, 70ís, and early 80ís have the same exact problem.
    Maximum output on all the zís from 70-83 is either 50 or 60 amps, except some of the turbos were supposedly 70 amps. Most of the 4 cylinder vehicles up to 75 only used a 35 amp max output alternator which just isnít enough power. Peak output on most factory alternators on these older cars is usually at 3500 rpm.

This is exactly why we helped develop our high output alternators. We make one model for the roadsters, and another model for all of the A engine, L engine, and Naps/z engine vehicles. These units are a direct bolt onto any of the aforementioned vehicles and donít require any wiring modifications. On a couple of 4 cylinder applications they do require a modified or completely different adjusting bracket but the zís are fine as is. If you have an externally regulated vehicle (used up thru 1977) all you have to do is unplug the regulator and remove it from the vehicle. No wiring mods to do there either.

Our HO alternators can produce 50 to 60 amps at idle, and reach peak output at about 2300 rpm which is over 1000 rpm sooner than the original alts. Peak output for our base model is rated at 105 amps but they will actually produce 125 amps. Our more powerful unit is rated at 120 amps but they will actually produce 140 amps. These alternators cannot damage your existing stock wiring in any vehicle. They will only produce what is asked of them. If you add electrical devices to your car that it was not designed for they should ALWAYS have their own wiring and NEVER should they be hooked up directly to your cars wiring system. They should either be wired directly to the battery or they should be directly wired to the battery. In other words, NO EXCEPTIONS.

Itís ok to use the stock wiring and switches for the triggering side of circuits, but NEVER for the heavy draw side of the circuits. Weíve had to replace or repair lots of wiring in these cars from people wiring these devices directly to the cars wiring or fuse block.

FYI, besides being hard on ecuís, switches, relays, power window motors, etc., the brown out effect that I mentioned before is extremely hard on fan motors and especially wiper motors. We can rebuild most wiper motors and bring them back up to full speed. The 74-78 zís need a headlight relay system installed as well but we havenít developed a good quality kit yet. Weíve seen a couple of partial kits available on the market, but the quality control is way too low and we wonít put our name on it. We will be developing one of those kits, but weíre not sure when quite yet. The 79-83 zxís also need this same system upgrade. The 74-83 cars run all the current through the headlight and dimmer switch just like the 240 and besides having a 3 volt drop from battery to headlights, it shortens the switchís life span drastically.