Replacing Your Hazard Switch w/a 3rd Party Unit

Date: Wed, 13 May 1998 22:48:59 EDT
From: Dan Masters
Subject: Re: A question for Dan Masters!

In a message dated 98-05-13 22:15:35 EDT, rick bacon writes:

> Hi Dan, I saved your article on bypassing the hazard switch in the TR6
> (from the VTR newsletter) and in the article, there is a drawing of what
> seems to be the back of the alternate switch. Am I wrong or should I use a
> 6 terminal toggle on/off switch? I went to the autoparts today and they
> have switches with 2 terminals. Should I keep looking? Am I missing
> something?

Rick,

No, you are not wrong, you need the 6 terminal switch. Sometimes the auto parts stores have them, but when they do, they usually have a "center off" position which is unsuitable for this application. These are typically used in a "selector" application, eg, "up" turns on the fog lights, "middle" turns all lights off, and "down" turns on the driving lights.Your best bet is to go to Radio Shack, or equivalent, and ask for a DPDT (double pole, double throw), two position, switch. With this switch, "up" disables the turn signals and turns on the hazard flasher. "down" turns off the hazard flasher and enables the turn signals. There is no "middle" position. The switch contacts operate as shown below:

1 2

3 4

5 6

In the up position, terminals 1 & 3 are connected, as are terminals 2 & 4. Terminals 5 & 6 are isolated. In the down position, terminals 3 & 5 are connected, as are terminals 4 & 6. Terminals 1 & 2 are isolated. As you can see, the switch is symetrical, so it doesn't matter which side you choose to call up.

In this instance, "up' and "down" depend entirely on how you mount the switch. If you prefer "down" to turn on the hazard flasher, just rotate the switch.

It is vital that you disable the turn signals when you use the hazard flasher; otherwise, a serious circuit overload can result. That is the reason for using the 6 terminal switch. If you don't, and you accidently bump the turn signal lever, voltage is back fed through the turn signal switch to the ignition switch, and every switched load -- wipers, heater fan, ignition coil, radio, etc -- that is left on will turn on and off with the hazard flasher if the key is off. That is the reason for the seemingly stupid practice of running power to the turn signal flasher through the hazard switch.

Dan Masters,
Alcoa, TN