Tech Tip #2 THE FUSE PANEL - WHERE SHOULD IT GO AND WHY?

During our past forty-plus years in business we have been asked many times what we thought of installing the fuse box in the rear of the car, which we will refer to as the trunk. There seem to be many reasons to do so, some of which make good sense -until you consider the consequences.

There are many things that get in the way and use up dashboard space:
■ air conditioners
■ air and heating ducts
■ elaborate pedal assemblies
■ recessed firewalls
■ cruise controls and ignition boxes hidden behind the firewall

These, and many other examples, may seem like a good reason that the wiring panel should go somewhere else. Someday soon a supplier will probably justify using glass inline fuses to reduce the space required to protect circuits. (See Tip #3) There already are some really small (so-called) harnesses, that seem to solve this problem. At Ron Francis Wiring these are known as "spaghetti." Some of them actually mount on the steering column and while this might seem like a good idea at first, the problem is that the "whole bowl" (of spaghetti) is exposed! Certain vehicle components need to be in certain locations, with no excuses.

The air conditioner should always be under the dash and the pedals won't work very well if they are in the trunk. There are good reasons why those components should be in front of the driver and, in my humble opinion, this is also where the wiring panel should be. Ok, why? Think of where the Big 10 (no longer the Big 3) put theirs? Under the dash? Under the hood? Under a seat? In the trunk? Put some percentages with those questions and think about it. The factory engineers have spent a lot more time working with the electrical system than we ever will, even though we seem to live this occupation 24/7.

Again, why? Reason number 1: With the fuse box in the front left corner, the wires are physically shorter. The steering column, dash gauges, dimmer and headlight switches and other driver controls and switches are right there. This means shorter wires resulting in less voltage loss (known as resistance). This will help provide all the juice your system has to muster for the all important (and sometimes embarrassing) "crank" mode, when your high torque, high horsepower, high compression motor says "give me all you've got or I won't start."

Reason number 2: remember that the upholsterer comes in after the car is wired and there is a potential for running that extra screw into the transmission case, gas tank, through a body panel, or through the hidden wire harness and maybe through that big bulky wiring bundle running from the fuse box in the trunk back up to the front where everything else is located.

We had a long time friend who came to us 15 years ago and insisted he could mount the fuse box in the very back of the car and never have a problem. He survived the upholsterer (or never mentioned it) and had a couple years years of reliable service. Then came the questions: "Why won't my alternator charge right?" Then it was "Why do I have dim lights," or "Why is the A/C motor getting hot?" Some of these problems may have been generated by a bad ground (which is another book by itself) but they are all compounded by the combination of improperly installed components. Yes, you can get through one or two years without a problem, unless you want to sell it before then ...

Copyright Ron Francis Wiring 2001