MINIATURE LAMPS
Mar 31, 2015
MINIATURE LAMPS
MINIATURE LAMPS
• There are several types of miniature lamps• You need to learn how to test and replace
them.
Bayonet style
- S.C. Bayonet -The lamp on the left is a Single Contact (S C)That means there is one filament inside the light bulb. The index pins are at the same height. It does not matter what way you put it into the light socket assembly.
- D.C. Index-The lamp on the left is a Double Contact (D C). There are two filaments and one is brighter then the other (tail lights & Brake Lights. Also the index pins are at different Heights so it will go into the light socket assembly only one way.
Bayonet style
Notice the index pins on the light One is higher then the other
Bayonet style
Single Contact Double Contact Double Contact Amber These all use the base of the lamp for Ground.
Wedge
These are very common on side markers and brakes and tail lights. Come in all different sizes and candle power.
Candle Power (cp) is the Brightness of the Lights or the light intensity. New Term is candela.
One side is power the other side is ground.
Wedge
They also come in different colors.
Wedge use a twist lock base
Plastic Wedge
The 3156 on the left has one filament therefore it has one wire on the each side of the base.
The 3157 on the right has two filaments so it has two wires on the base.
Clear & Amber
Some bulbs are clear Some are amber for turn signals
Same is true on Plastic Wedge
Tail Light Lens
Clear Turn signal Amber Turn signal
May use a clear bulb behind a amber lens
Must use a amber bulb behind a clear lens
To test a Plastic Wedge bulbTake Negative wire and clip it to both wires on one side
Attach the Positive lead to the front side of the bulb
Flip the bulb over and attach the Positive lead to the other side
See how we have wires on each side of the bulb (3157)
To test a Wedge bulbHook up the wires to both sides of the bulb And it will turn on
Courtesy lamps
Ridged Loop topEnd Cap bottom
Festoon type
Instrument panel lights
Some times we need to replace dash lights how do we do that?
Many different types of bulbsused in Instrument panels
194 Used in a twist lock socket
#74 #37 #24 #194
#74 too small?..#194 too big? Could be a # 24
#74 & 37 are T1 3/4 #24 are T2 3/4 #194 are T3 1/4
Some dash lights use LED’sLED Lights come in several sizes
NeoWedge Twist Lock BAX series
Pictures from
NeoWedge series
• Available in 3mm, 4mm, 5mm sizes• To choose the correct bulb, measure the
diameter of the base• Type A (T3) 3mm base is 8mm= 5/16“• Type B (T4) 4mm base is 10mm= 3/8“• Type C (T5) 5mm base is 12mm= 15/32“• Info from
NeoWedge series
Remember when you test these light bulbs they are LED’s you must have the right Polarity in other words, you have to Hook up the power to the right side. A Diode is a one way check valve. If you hook it up backwards it will not work.
Different colored Dash lights
MINIATURE LAMPS
Picture - Thanks to thehttp://www.bulbman.com