---
title: 'Lotus Esprit GT3 — Main Beam Modification'
url: 'https://andywhittaker.com/articles/lotus-esprit-gt3/lotus-esprit-gt3-main-beam'
markdown: 'https://andywhittaker.com/articles/lotus-esprit-gt3/lotus-esprit-gt3-main-beam.md'
lang: en
date: '2002-05-18'
description: 'Main Beam Modification Since I got my GT3, I was disappointed that only the inside pair of the four, front headlights illuminate during main beam. The outside pair always switch off. This seemed like a waste of headlights to me; so I set about modifying the electrics to cause all four lights to com…'
taxonomy:
category:
- articles
tag:
- lotus
- esprit
- gt3
- cars
---
## [Lotus Esprit GT3 — Main Beam Modification](https://andywhittaker.com/articles/lotus-esprit-gt3/lotus-esprit-gt3-main-beam)
18th May 2002 [lotus](https://andywhittaker.com/tag:lotus#body-wrapper) [esprit](https://andywhittaker.com/tag:esprit#body-wrapper) [gt3](https://andywhittaker.com/tag:gt3#body-wrapper) [cars](https://andywhittaker.com/tag:cars#body-wrapper)
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# Main Beam Modification
Since I got my GT3, I was disappointed that only the inside pair of the four, front headlights illuminate during main beam. The outside pair always switch off. This seemed like a waste of headlights to me; so I set about modifying the electrics to cause all four lights to come on.
After looking at the circuit diagrams, I'm amazed that it's so easy. All you have to do is to change the main beam relay.
Note: USA models of the Esprit switch all 4 main beams on.
## Relay Location
All you have to do is swap the relays over. Lotus have kindly done the rest of the wiring.
### MY98 (~September 1997 onwards)
The relay you need to change is relay "I" within the front storage bay. On right-hand drive cars the relay is here, highlighted in red:
On left-hand drive cars the relay is here:
### MY94 (Revised Harness)
Right-hand drive cars:
Left-hand drive cars:
### MY94 (Earlier Harness)
Right-hand drive cars:
Left-hand drive cars:
## Choosing a Suitable Relay
Because the wiring is already in place, you need to swap your existing SPST (Single Pole, Single Throw) relay with a DPST (Double Pole, Double Throw) type. Automotive relays have numbers and letters on their cases that let you choose the correct type.
Lucas make a suitable relay **SRB521.** So do Lotus **B082M6182F**.
The required relay is also available from Demon-Tweeks, Wrexham, Wales, UK. You require catalogue item **LMA799**. Their web-site is at where you can order on-line. Note that this relay is not listed in their on-line catalogue, you'll have to telephone them.
You need to select a relay that has five spade connectors rather than four. The fifth connector will be labelled 87b.
## Final Note
Check you've pulled the correct relay by a simple test. Turn your head lights on, and then push your direction indicator stalk forward to select main beam. If all of the front lights go out, then you've the correct relay!
Having four main beam headlights maybe illegal in your country. Therefore, you shouldn't do this modification that lets you see better, should you?
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Changes last made on: 18 May 2002 16:19 -0400
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