[Casper98GT]

Installed and went to hook up a switch to it. I have a 3 terminal switch, one for acces. one for 12v and another for ground. You know, youre normal switch with a light in it. Well....i hooked up the terminal from the fan to the swtich. Then a 12v to the switch. Now Flex-a-lite says not to conenct ground to the switch if im not using their switch. Well im not and i forgot and i connected it to ground and it blows the cigar lighter fuse everytime. Why can i not use the ground on this switch when in series with a Flex-a-lite system without their switch. Whats so special about their switch which im sure cost 20 bucks. I can put the ground to the switch but when i turn the fan on it blows. If i keep it off, the switch lights up but when i turn it on....snap.

Just wondering.

[GTsetGO]

i kept blowing my fuse when i wired it up in one of my older cars. it's just the amps that the fan is using on start up exceeds the fuses capacity.

[Casper98GT]

Thats what i thought, but another situation. ....

First we know that the switch im using only needs a ground to power up the light in the switch. It serves no other purpose.

Using ground in the way this fan is setup isnt needed. All the switch does is give 12v's to the fan when switched on. If i leave ground out of the situation i can turn the fan on and off and the fuse will not blow. I dont need a rad little red light in my interior....im just confused why it would blow when i hook up to ground. Then turn on. I guess my only concern is possible i have the 12v and the power to the fan hooked up to the wrong terminal on the switch.

[GTsetGO]

that's a good question brah.

[Casper98GT]

I guess i'll find out when i get home. Cant wait to finally be done working on it and start driving it. Owned it now for 2 weeks and only driven it twice.

[IcantDo55]

You need to install a RELAY! You WILL burn up any switch and loose way too much current running 12+ga wire to the dash and back.

Here some good reading on relays.

http://www.bcae1.com/relays.htm

Summary:

The Famous Bosch Relay

Bottom View:
The most commonly used relay in car audio and security is the Bosch relay. The picture below is the bottom of a Bosch relay. Take note of the markings (85, 86, 87, 87a, & 30) near the terminals.



Internal Workings of Bosch relay:
The following diagram shows what those external terminals are connected to on the inside of the relay. When there is no difference of potential (voltage) across terminals 85 and 86 (the coil), the relay's movable contact (connected to terminal 30) is held, by spring tension, against the electrical contact which is connected to terminal 87a (the normally closed contact). In other words, when no voltage is applied the the relay coil, terminal 87a is connected to terminal 30. When 12 volts is applied to the relay coil (terminals 85 and 86), the movable contact (connected to terminal 30) is pulled down/in by the electromagnet (coil) so that it physically contacts the electrical contact which is connected to terminal 87. Again, in other words, if battery voltage is applied to the relay coil (terminals 85 and 86) terminal 30 will be connected to terminal 87. The red dashed line shows the path in which electrical current flows from/through terminal 30 to the contact of terminal 87a when the relay coil is NOT energized.



Remember that the relay coil has to have a difference of potential between terminals 85 and 86 in order for the coil to pull the armature in/down. This means that you may apply battery voltage to either terminal 85 OR 86 and then ground the OTHER terminal. The positive battery voltage OR the ground connection may be broken to make relay switch terminals (87 to 87a).

The wiring diagram below is all I could find quick, the fog lights are the fan.