Heineken's Garage

Introduction

Around the 100.000 to 150.000 km range the first illumination and indicator bulbs in the Gauge Cluster start to fail. Replacing individual bulbs isn't economical considering the effort to get the cluster out of the car. Replacing all bulbs is the preferred route (except for AT vehicles - which will be explained below).

JDM 1997 AT Cluster

All bulbs can be replaced without disassembling the cluster, except the AT indicators. Simply turn the socket and pull them straight out of the PCB. Note that some bulb locations might not be populated and that blue sockets are of different brightness than black sockets but otherwise exchangeable. It's therefore advised to take notes or pictures before removing more than one bulb.

Bulb Types

Five different bulbs are used across the clusters. Four of them being wedge-based, following this classification:

• Diameter: 10 mm → T10
• Thickness of the base: 2.1 mm → W2.1 ('W' is for wedge)
• Width of the base: 9.5 mm → x9.5d ('d' is for dual - two wires)
• Result: T10 W2.1 x 9.5d (wattage and voltage to be added)

	Large (Illumination)	Green (Illumination)	Blue (Indicator)	Black (Indicator)	Gear (Indicator)
Honda Part Number	37237-SA5-003 (lamp only) 37102-SA5-003 (incl. holder)	37103-SL0-003 (incl. holder)	37102-S84-003 (incl. holder)	35505-SA5-003 (incl. holder)	78181-SF1-612 (incl. holder)
Diameter	10 mm	6.5 mm	5 mm	5 mm	4.2 mm
Wattage	3.4 W	3.0 W	2.0 W	1.4 W	1.0 W
Classification	T10 W2.1 x 9.5d	T6.5 W2 x 5d	T5 W2 x 4.6d	T5 W2 x 4.6d	T4.2

The green holder illumination bulb is a little exotic having a quite high wattage for a 6.5 mm design. As a result, the holder tends to become brittle due to excessive heat and should be replaced together with the bulb.


AT Clusters

The fifth bulb type (Gear Indicator - not in the picture above) is used to indicate the selected gear in AT models. It's T4.2 and has two long wires instead of a wedge base.
These practically don't wear out, except the 'D' indicator as it's lit most of the time - replacement of that single bulb is sufficient.
Note that replacing requires the PCB to be removed. A delicate task as it's easy to break off the hair-thin wires that connect the gauges to the PCB by over-tightening the corresponding screws. Please see Gauge Cluster - Capacitor Replacement for further instructions.


Alternative Sources

If you are replacing all bulbs or servicing more than one cluster it might be interesting to get bulbs in larger quantities. The company BOSMA is selling all of above bulbs, even the ones for the gear indicator. Minimum order is 10 pieces but they are verified to fit and are working fine.

	Large (Illumination)	Green (Illumination)	Blue (Indicator)	Black (Indicator)	Gear (Indicator)
Voltage	12 V	12 V	12 V	12 V	12 V
Wattage	3.0 W	3.0 W	2.0 W	1.2 W	1.0 W
Classification	T10 W2.1 x 9.5d	W2 x 6.6d T6.5	T5 W2 x 4.6d	T5 W2 x 4.6d	T4.2
Order Number	5012363-BOSMA	501248-BOSMA-0002	501235-BOSMA-0002	50123512-BOSMA-0002	501273-0002

Note that obtaining the correct replacement bulbs isn't an easy task since some of the values in the repair manual are incorrect, some bulbs carry US-American numbers, are rated at 14 V instead of the European 12 V and the green holder bulbs are simply rare - in some cases measuring the current through the bulb was necessary for verification.