I got bored one day and made this list of bulbs for the different places on the 2001 1500 Ram. I'm pretty sure that the 2500 and 3500 are the same.

Ash Tray Light
161
CEC 2.7W 14V 0.19A Mini T3.25 Bulb

Backup Light
ZEVO2 G2 1156LED.BP2 EN-SP UPP 2SKU 72CS
Sylvania 1156 ZEVO LED Mini Auto Stop, Tail Light
12898B2
PHILIPS LED 1156 White Miniature Automotive Stop/Tail Light
12839REDB2
Philips LED 1156 Vision Red Mini Auto Stop, Tail Light
1156ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 1156 SilverStar Mini Auto Stop, Tail Light
1156LLB2
Philips 1156LL Long Life Auto Bulb
1156LL.BP2 2/SKU 20/BX 200/CS
Sylvania 1156 Long Life Mini Auto Stop, Tail Light
1156B2
Philips 1156 Standard Auto Bulb
1156
CEC 26.9W 12.8V 2.1A Mini S8 Bulb

Brake Light
ZEVO2 G2 3157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 3157 ZEVO LED Automotive Bulb
ZEVO2 G2 1157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 1157 ZEVO LED White Auto Bulb
3157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 3157 SilverStar Automotive Bulb
3157NALLB2
Philips 3157NA Long Life Amber Automotive bulb
3157LLB2
Philips 3157LL Long Life Auto Bulb
3157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 3157 Long Life Automotive Bulb
3157B2
Philips 3157 Standard Auto Bulb
3157
CEC 27W or 8.3W, 12.8V or 14V, 2.1A or 0.59A Mini S8 Bulb
12840REDB2
Philips LED 3157 Vision Red Mini Auto Stop, Tail Light
12836REDB2
PHILIPS Vision LED 1157 Red Miniature Automotive Stop/Tail Light
1157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 1157 SilverStar Auto Bulb
1157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 1157 Long Life Auto Bulb
1157B2
Philips 1157 Standard Auto Bulb
1157
Eiko 27W or 8.3W, 12.8V or 14.0V, 2.10A or 0.59A Mini S8 Bulb

Cargo Light
ZEVO2 921LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 921 ZEVO LED Mini Auto Bulb
921ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 921 SilverStar Mini Auto Bulb
921LLB2
Philips 921LL Long Life Mini Auto Bulb
921B2
Philips 921 Standard Mini Auto Bulb
921
CEC 18W 12.8V 1.4A Mini T5 Bulb

Center High Mount Stop
ZEVO2 921LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 921 ZEVO LED Mini Auto Bulb
921ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 921 SilverStar Mini Auto Bulb
921LLB2
Philips 921LL Long Life Mini Auto Bulb
921B2
Philips 921 Standard Mini Auto Bulb
921
CEC 18W 12.8V 1.4A Mini T5 Bulb

Cornering Light
ZEVO2 G2 3157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 3157 ZEVO LED Automotive Bulb
3157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 3157 SilverStar Automotive Bulb
3157NALLB2
Philips 3157NA Long Life Amber Automotive bulb
3157LLB2
Philips 3157LL Long Life Auto Bulb
3157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 3157 Long Life Automotive Bulb
3157B2
Philips 3157 Standard Auto Bulb
3157
CEC 27W or 8.3W, 12.8V or 14V, 2.1A or 0.59A Mini S8 Bulb
12840REDB2
Philips LED 3157 Vision Red Mini Auto Stop, Tail Light

Courtesy Light
ZEVO2 194LED.BP EN-SP 1/SKU 36/CS
Sylvania 194 Mini Auto Bulb
194ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 194 SilverStar Mini Auto Bulb
194LLB2
Philips 194LL Long Life Auto Bulb
194B2
Philips 194 Standard Mini Auto Bulb
194B LL BP 20
Sylvania 194 Blue Long Life Mini Auto Bulb
194
CEC 3.8W 14V 0.27A T3.25 Mini Auto Bulb
127916000KB2
Philips LED 194 Vision Interior, Exterior Auto Bulb

Engine Compartment Light
561B2
Philips 561 Standard Auto Bulb

Front Fog
896B1
Philips 896 Standard Mini Auto Bulb

Glove Box Light
1891
CEC 3.36 Watt, 14.0 Volt, 0.24 Amp T-3 1/4 Indicator/Automotive Lamp

High Beam Headlight
9004ST.BP2 EN-SP 2/SKU 8/BX 80/CS
Sylvania 9004 SilverStar Halogen Headlight
9004/10PK
Eiko 9004, HB1 Standard High and Low Beam Headlight
9004.BP2 EN-SP 2/SKU 12/BX 120/CS
Sylvania 9004 Basic Halogen Headlight
9004 SZ PBX 6 TWIN 36
Sylvania 9004 zXe Halogen Headlight
9004
CEC Standard Halogen 9004/HB1 Low and High Beam Headlight

Ignition Light
1445B2
Philips 1445 Standard Auto Indicatior Light

Instrument Panel
158
CEC 3.36W 14V 0.24A Mini T3.25 Bulb

License Light
ZEVO2 168LED.BP EN-SP 1/SKU 36/CS
Sylvania 168 Interior, Exterior Auto Bulb
168ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 168 SilverStar Interior, Exterior Auto Light
168LL.BP2 2/SKU 20/BX 200/CS
Sylvania 168 Long Life Interior, Exterior Auto Light
168B2
Philips 168 Standard Instrument Panel Bulb

Low or Dual Beam Headlight
9007XV.BP2 EN-SP 2/SKU 12/BX 120/CS
Sylvania 9007 XtraVision Halogen Headlight
9007SU.BP2 EN-SP 2/SKU 8/BX 80/CS
Sylvania 9007 SilverStar Ultra High and Low Beam Headlight
9007ST.BP2 EN-SP 2/SKU 8/BX 80/CS
Sylvania 9007 SilverStar Halogen Headlight
9007BVB1
Philips 9007, HB5 BlueVision High and Low Beam Headlight
9007B1
Philips 9007, HB5 Standard High and Low Beam Headlight
9007/CEC
CEC Brand Standard Halogen 9007/HB5 Low and High Beam Headlight
9007.BP2 EN-SP 2/SKU 12/BX 120/CS
Sylvania 9007 Basic Halogen Headlight
9007
Eiko 9007, HB5 Low & High Beam Headlight
9004ST.BP2 EN-SP 2/SKU 8/BX 80/CS
Sylvania 9004 SilverStar Halogen Headlight
9004/10PK
Eiko 9004, HB1 Standard High and Low Beam Headlight
9004.BP2 EN-SP 2/SKU 12/BX 120/CS
Sylvania 9004 Basic Halogen Headlight
9004 SZ PBX 6 TWIN 36
Sylvania 9004 zXe Halogen Headlight
9004
CEC Standard Halogen 9004/HB1 Low and High Beam Headlight

Rear Side Marker
ZEVO2 194LED.BP EN-SP 1/SKU 36/CS
Sylvania 194 Mini Auto Bulb
194ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 194 SilverStar Mini Auto Bulb
194LLB2
Philips 194LL Long Life Auto Bulb
194B2
Philips 194 Standard Mini Auto Bulb
194B LL BP 20
Sylvania 194 Blue Long Life Mini Auto Bulb
194
CEC 3.8W 14V 0.27A T3.25 Mini Auto Bulb
127916000KB2
Philips LED 194 Vision Interior, Exterior Auto Bulb

Rear Turn Signal
ZEVO2 G2 3157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 3157 ZEVO LED Automotive Bulb
ZEVO2 G2 1157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 1157 ZEVO LED White Auto Bulb
3157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 3157 SilverStar Automotive Bulb
3157NALLB2
Philips 3157NA Long Life Amber Automotive bulb
3157LLB2
Philips 3157LL Long Life Auto Bulb
3157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 3157 Long Life Automotive Bulb
3157B2
Philips 3157 Standard Auto Bulb
3157
CEC 27W or 8.3W, 12.8V or 14V, 2.1A or 0.59A Mini S8 Bulb
12840REDB2
Philips LED 3157 Vision Red Mini Auto Stop, Tail Light
12836REDB2
PHILIPS Vision LED 1157 Red Miniature Automotive Stop/Tail Light
1157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 1157 SilverStar Auto Bulb
1157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 1157 Long Life Auto Bulb
1157B2
Philips 1157 Standard Auto Bulb
1157
Eiko 27W or 8.3W, 12.8V or 14.0V, 2.10A or 0.59A Mini S8 Bulb

Tail Light
ZEVO2 G2 3157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 3157 ZEVO LED Automotive Bulb
ZEVO2 G2 1157LED.BP2 EN-SP 2/SKU 72/CS
Sylvania 1157 ZEVO LED White Auto Bulb
3157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 3157 SilverStar Automotive Bulb
3157NALLB2
Philips 3157NA Long Life Amber Automotive bulb
3157LLB2
Philips 3157LL Long Life Auto Bulb
3157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 3157 Long Life Automotive Bulb
3157B2
Philips 3157 Standard Auto Bulb
3157
CEC 27W or 8.3W, 12.8V or 14V, 2.1A or 0.59A Mini S8 Bulb
12840REDB2
Philips LED 3157 Vision Red Mini Auto Stop, Tail Light
12836REDB2
PHILIPS Vision LED 1157 Red Miniature Automotive Stop/Tail Light
1157ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 1157 SilverStar Auto Bulb
1157LL.BP2 2/SKU 20/BX 200/CS
Sylvania 1157 Long Life Auto Bulb
1157B2
Philips 1157 Standard Auto Bulb
1157
Eiko 27W or 8.3W, 12.8V or 14.0V, 2.10A or 0.59A Mini S8 Bulb

Dually Fender Side Marker (for both the yellow and red lenses)
ZEVO2 194LED.BP EN-SP 1/SKU 36/CS
Sylvania 194 Mini Auto Bulb
194ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 194 SilverStar Mini Auto Bulb
194LLB2
Philips 194LL Long Life Auto Bulb
194B2
Philips 194 Standard Mini Auto Bulb
194B LL BP 20
Sylvania 194 Blue Long Life Mini Auto Bulb
194
CEC 3.8W 14V 0.27A T3.25 Mini Auto Bulb
127916000KB2
Philips LED 194 Vision Interior, Exterior Auto Bulb

Cab Roof Clearance Light
ZEVO2 194LED.BP EN-SP 1/SKU 36/CS
Sylvania 194 Mini Auto Bulb
194ST.BP2 EN-SP 2/SKU 12/BX 72/CS
Sylvania 194 SilverStar Mini Auto Bulb
194LLB2
Philips 194LL Long Life Auto Bulb
194B2
Philips 194 Standard Mini Auto Bulb
194B LL BP 20
Sylvania 194 Blue Long Life Mini Auto Bulb
194
CEC 3.8W 14V 0.27A T3.25 Mini Auto Bulb
127916000KB2
Philips LED 194 Vision Interior, Exterior Auto Bulb

Tailgate Bar Light
Sylvania Standard 579
Sylvania Long Life 579LL
Philips Standard PC579CP
Philips Longer Life 579LL
CEC T5 WEDGE 12V 0.75A 9CP