What Size Bulbs Does a 1991 GMC Jimmy 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 1991 GMC Jimmy Have?
The 1991 GMC Jimmy features an extensive lighting system with 13 bulb positions. It uses halogen technology with H4703 LED low beams and PC74 or PC194 or 168 high beams in a dual-bulb configuration. The Jimmy has been available from 1989 to 2005, and the 1991 model falls in the early-generation years.
Can You Put LED Bulbs in a 1991 GMC Jimmy?
To upgrade the 1991 GMC Jimmy headlights to LED, you will need a H4703 LED LED kit for the low beams and a PC74 or PC194 or 168 LED kit for the high beams. Start with the low beams since they are used most often and have the biggest impact on nighttime visibility. For the fog lights, a LED Fog Light LED bulb provides a clean white output that pairs well with LED headlights.
How to Replace Bulbs on a 1991 GMC Jimmy
To remove the headlight bulb, disconnect the wiring harness, then twist the bulb counter-clockwise and pull it straight out of the housing. Older model years like the 1991 Jimmy typically offer easy access to the headlight bulbs from behind the headlight assembly under the hood. Most owners can complete the swap in under 10 minutes per side. When installing the new bulb, avoid touching the glass with bare fingers. Skin oils create hot spots that shorten bulb life. Wear clean gloves or handle the bulb by its plastic base only. The fog lights are accessed from underneath the front bumper. You may need to remove a few plastic clips or screws from the fender liner to reach the LED Fog Light fog light socket.
Full Upgrade Bundle
Upgrade All 13 Positions at Once
1991 GMC Jimmy Complete Bulb Size Chart
| Position | Bulb Size | Shop |
|---|---|---|
Low Beam | H4703 LED | Buy H4703 LED |
High Beam | PC74 or PC194 or 168 | Buy PC74 or PC194 or 168 |
Fog Light | LED Fog Light | Buy LED Fog Light |
Brake Light | PC74 or 194 or 168 | Buy PC74 or 194 or 168 |
Side Marker | 194 LED | Buy 194 LED |
Turn Signal Front | 2057 LED or 3057NA LED | Buy 2057 LED or 3057NA LED |
Turn Signal Rear | 2057 LED | Buy 2057 LED |
Reverse Light | 1156 | Buy 1156 |
Dome Light | 211-2 | Buy 211-2 |
License Plate | 67 | Buy 67 |
Map Light | 906 | Buy 906 |
Parking Light | 2057 or 194NA or 3057NA | Buy 2057 or 194NA or 3057NA |
Trunk Light | 570 or 1142 | Buy 570 or 1142 |
Want to upgrade everything at once?
Shop Complete LED Kit for 1991 GMC JimmyHow Long Do 1991 GMC Jimmy Headlight Bulbs Last?
Standard halogen headlights on the 1991 GMC Jimmy have an expected lifespan of 500 to 1,000 hours, which works out to roughly 2 to 3 years of normal use. Signs of a failing halogen bulb include noticeably dimmer output, a yellowish tint compared to the other headlight, or intermittent flickering. At 35 years old, the original bulbs on your Jimmy are likely overdue for replacement. Even if they still illuminate, reduced brightness significantly impacts nighttime safety. When one headlight burns out, replace both sides at the same time. Bulbs from the same batch age at similar rates, and mismatched brightness is distracting to oncoming drivers.
What Bulbs Are Compatible with the 1991 GMC Jimmy?
The H4703 low beam bulb on the 1991 GMC Jimmy is a specific fitment. There are no widely recognized cross-compatible alternatives, so make sure to purchase the exact H4703 size. Using the wrong bulb size can cause improper beam patterns that reduce your visibility and blind other drivers. It can also cause overheating inside the headlight housing, potentially warping the plastic lens or reflector. Always verify the bulb number before purchasing.
1991 GMC Jimmy Headlight FAQ
Did GMC Jimmy Bulb Sizes Change Over the Years?
Over its production run from 1989 to 2005, the GMC Jimmy has seen bulb size changes in the Low Beam, High Beam and Fog Light positions. The 1991 model uses the earlier bulb specification that was in place before the change around 2002. Always verify the exact bulb size for your specific 1991 model year using the chart above, as using the wrong size can result in poor fitment or reduced light output.
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Other Vehicles That Use H4703 LED Bulbs
These vehicles from other makes also use a H4703 LED low beam bulb: