What is the low beam headlight bulb size for a 1989 Isuzu I-Mark?

The 1989 Isuzu I-Mark uses a 9004 LED bulb for the low beam headlights. We recommend upgrading to LED for better visibility.

What is the high beam headlight bulb size for a 1989 Isuzu I-Mark?

The high beam bulb size for the 1989 Isuzu I-Mark is 9004 LED.

Why are my 1989 Isuzu I-Mark headlights dim?

Dim headlights on a 1989 Isuzu I-Mark can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a 9004 LED LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 1989 Isuzu I-Mark fog light?

The 1989 Isuzu I-Mark uses a H3 LED bulb for the fog light position.

Is the 1989 Isuzu I-Mark single or dual beam?

The 1989 Isuzu I-Mark uses a single bulb (dual filament) headlight system. This means one bulb controls both high and low beams.

Can I install LED bulbs on my 1989 Isuzu I-Mark?

Yes, the 1989 Isuzu I-Mark comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a 9004 LED LED conversion kit for the low beams.

Does the 1989 Isuzu I-Mark have fog lights?

Yes, the 1989 Isuzu I-Mark takes a H3 LED bulb for the fog light position.

Did the 1989 Isuzu I-Mark change headlight bulb sizes from the previous year?

No — the 1989 Isuzu I-Mark uses the same bulb sizes as the 1988 model. This configuration has been consistent across the 1988–1990 generation.

How do I change the headlight on a 1989 Isuzu I-Mark?

Turn off the vehicle and open the hood. Locate the headlight assembly from behind, remove the dust cover or retaining clip, disconnect the wiring harness, twist the old 9004 LED bulb counter-clockwise to remove it, then insert the new bulb and reassemble. The whole process typically takes 10 to 30 minutes per side depending on accessibility.

Are LED headlights legal for a 1989 Isuzu I-Mark?

LED bulbs used off-road or in auxiliary lights are legal everywhere. For on-road headlight use, legality varies by state. Many states allow LED retrofits as long as the beam pattern meets DOT standards. For the best legal compliance, choose a DOT-approved 9004 LED LED kit that is designed as a direct replacement and produces a proper cutoff pattern without excessive glare.

How much does it cost to replace 1989 Isuzu I-Mark headlights?

A pair of halogen 9004 LED bulbs costs $15 to $40, while LED conversion kits run $25 to $60 per pair. If you have a shop do the work, expect an additional $20 to $50 in labor per bulb. Replacing them yourself at home saves the labor cost and usually takes under 30 minutes.

What is the difference between halogen and LED for a 1989 Isuzu I-Mark?

Halogen bulbs produce a warm yellow light (around 3200K), last 500 to 1000 hours, and draw more power. LED bulbs emit a brighter white light (5000-6000K), last 25,000+ hours, and use less energy. LED upgrades for the 9004 LED position are available as direct plug-and-play replacements.

The 1989 Isuzu I-Mark shares its bulb sizes with the 1988–1990 generation.

Fitment Guaranteed for 1989 Isuzu I-Mark

What Size Bulbs Does a 1989 Isuzu I-Mark Use?

Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.

Installation Difficulty

Easy (Plug and Play)

Est. Replacement Cost

$15 - $40 (Halogen) / $30+ (LED)

What Lighting System Does the 1989 Isuzu I-Mark Have?

The 1989 Isuzu I-Mark utilizes a refined lighting configuration featuring 12 distinct bulb positions. It features an extensive lighting system powered by a halogen-based setup where a single 9004 LED dual-filament bulb handles both low and high beam duties within the same reflector. This model belongs to the late years of the I-Mark's 1981-1990 production span.

Can You Put LED Bulbs in a 1989 Isuzu I-Mark?

Upgrading to LED is one of the most effective ways to modernize your Isuzu's appearance and safety profile. Since your I-Mark uses a single 9004 LED bulb for both high and low beams, ensure your chosen LED kit is "dual-beam" compatible. This allows the LED circuitry to mimic the two-filament design of the original halogen bulb. Don't forget the H3 LED fog lights; switching these to LED can dramatically improve your visibility in adverse weather.

1989 Isuzu I-Mark Bulb Size Chart

Position	Bulb Size	Shop
Low Beam	9004 LED	Buy 9004 LED →
High Beam	9004 LED	Buy 9004 LED →
Fog Light	H3 LED	Buy H3 LED →
Brake Light	74	Buy 74 →
Side Marker	194 LED	Buy 194 LED →
Turn Signal Front	1157 LED	Buy 1157 LED →
Turn Signal Rear	1073 LED	Buy 1073 LED →
Reverse Light	1073	Buy 1073 →
License Plate	168	Buy 168 →
Parking Light	1157	Buy 1157 →
Trunk Light	LED Light	Buy LED Light →
Tail Light	1157	Buy 1157 →

How do the 1989 Isuzu I-Mark's bulbs compare to other years?

The 1989 Isuzu I-Mark uses the same bulbs as the 1988 model.

The 1990 model continues with the same bulb sizes.

This bulb configuration covers the 1988–1990 model years. ← 1988 1990 →

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Other I-Mark Years

1990 1988 1987 1986 1985 1984 1983 1982 1981

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