CBC Do you ever feel overworked? H Your vehicles electrical system can feel the same way.

CBC Circuit Protection

CBC The three types of circuit defects are: H Opens H Shorts to ground & to voltage H High Resistance – poor connections C75-78 L64-71

CBC Opens Wire is Broken

CBC Opens H An Open circuit is were there is no connection. I usually refer to this as (cut copper) because nothing can get through. Can happen on positive or the ground side of the circuit. A broken wire, blown fuse or a switch in the off position can cause this.

CBC High Resistance H Connections not touching properly Could be loose or paint not cleaned off or a build up of corrosion. (green copper) This could cause a light to be dim or a blower motor to be slower then normal.

CBC High Resistance Corrosion, paint or a loose connection will not allow all the electricity thru the connection volts 8.2 volts You lose voltage going through every connections

CBC Short to ground H A short to Ground Means that we have a path to ground before the load. This will cause extra current to flow and will burn out the fuse or blow the circuit breaker. (copper to steel) H The only time this is not true is when the short is the control side of a relay. Then for example on a horn circuit, the horn will sound.

CBC Short to ground Wire touch or rubbing up against the wire causing a fuse to blow and the light not going on.

CBC Shorted H Another form of short to ground is a relay or motor that is shorted. Take a look at the relay if a wire connects between 85 and 86 bypassing the load it will blow the fuse.

CBC Short to voltage H A short to voltage usually happens when two wires of different circuits come together and touch. For example a taillight and a brake light wires could be touching and the brake light would be on whenever the lights are on. (copper to copper)

CBC Short to voltage Light switch is off but light is still on because a hot wire is touching the wire and feeding 12 volts of electricity to the wire.

CBC Lets Review No Problem Circuit works fine

CBC Open Circuit no current can flow

CBC High Resistance Light is dim

CBC Short to ground Wire touch's ground Blows fuse

CBC Short to voltage Power feeding circuit light on all the time

CBC Fuse boxes H A fuse box can be located in several different locations can be under the hood, under the dash, in the trunk or somewhere in the circuit.

CBC Toyota Fuse box Toyota Fuse box

CBC Fuses (Page C52 ) H Glass Cartridge (Old Cars) How to pull them

CBC Two reasons for blowing Where do they blow? Why?

CBC Fuses Ceramic & Glass H Rated by current failure level H Three letter code for type and size (SFE AGC) H Glass style replaces ceramic H Caution in pulling

CBC Fuse types

CBC Fuse Colors ATCATM MINI MAX Black1 Gray22 Violet33 Pink44 Tan55 Brown7 ½ Red10 50 Lt. Blue15 60 Yellow20 Clear25 Green30 Amber4070 Orange40 Natural80

CBCFuses H Auto-fuse (blade type) ATO /ATC H Mini-fuse H Maxi-fuse – Test holes – Pulling MAXI ATC/ATO ATM or MINI Low profile Mini fuses

CBC Fuses

Smart Glow Fuses Lights up when the fuse blows

CBC Ceramic Fuses Ceramic Fuses many times called GBC Fuses used in Older European cars VW Beetle, BMW etc.

CBC Maxi-fuses H Combination blade / cartridge H Protects main circuits H Safer than fusible link H Cover fewer circuits than a fusible link H In Power Distribution box

CBC Cartridge Fuses Male Pal fuses FLM Male Female Pal fuses FLF Female Bolt on Pal Fuses Bolts into Fuse box Also called Cartridge Fuses

CBC New Circuits H What size of fuse should I install? ?

CBC Add A Circuit Fuse Holder Tap ATC Add-A-Circuit Fuse Holders This ingenious device allows quick and easy installation of additional 12V accessories without the need for splicing. Plugs into an existing fuse holder. Protects original circuit and provides a wire lead for the new circuit. Thanks to The Repair Connector Store

CBC Fuse Pullers Many different types

Fusible Links H Lighter gauge wire than main conductor H Covered with special insulation H Protect Main circuits H Usually under hood

Fusible Links H Insulation – Visual checks dont work H Installing a new link – Size 4 wire sizes smaller (4 numbers larger) – Soldering

CBC Circuit Breaker H Why circuit breakers H Styles H Deterioration

CBC Circuit Breakers

CBC TESTING CIRCUIT PROTECTION DEVICES H Must inspect closely H Type of failure determines cause H Best to use DVOM H Do not overload circuit by installing to large of fuse or tin foil H Connections must be tight H Do not use un-fused jumper wire

CBC TESTING FUSES H Best to use DVOM, Test light can be used H Power must be flowing to test H Some Fuses are hot all the time H To check the others the H Key must be on H Lights must be on H And some cars it must be running to check some fuses like the charging fuse.

CBC TESTING FUSES H Must check each side of the fuse. H Must have power on both sides. H If neither side has power you need to find out why? Turn on key! Turn on Lights! Turn on dash light controls! Turn on engine! Etc H If only one side has power you have a Blown fuse replace with the same size.

CBC Replacing Circuit Protection H Fuses – if it blows you must replace it. H Fusible Links – if it blows cut out and replace with same size and length of wire. H Circuit breakers – if it trips it should reset.

CBC End End of ofcircuitprotection