Automotive Ambient Lighting Specification Example for City Buses: Waterproof Version
Automotive Ambient Lighting Specification Example for City Buses: Waterproof Version
This is a worked specification for automotive ambient lighting in a waterproof version programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The waterproof version version exists because the duty cycle on city buses is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually inconsistent hardness between lots.

Example specification
| Item | Automotive Ambient Lighting |
|---|---|
| Application | City Buses |
| Version | Waterproof Version |
| Base material | Zinc Plated Steel |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | as machined |
| MOQ | 200 pieces per specification |
| Sampling | 10 working days, 5 days per revision |
| Compliance | IATF 16949 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Zinc Plated Steel, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- ultrasonic cleaning
- heat treatment
- electroplating
- surface grinding
- laser cutting
- shot blasting
Where this example applies
Programmes that run waterproof version most often specify this build for city buses. Related applications include delivery vans, three-wheelers, workshop replacements, construction equipment, assembly programmes.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
What is the minimum order quantity?
The standard MOQ is 200 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the IATF 16949-compliant build instead of a fresh interpretation.
How long does sampling take?
Samples leave the factory in 10 working days, and each revision round adds about 5 days once you have seen the first piece.
How is packing specified?
Individual packing, inner box quantity and carton marking are confirmed at quotation stage so the cartons arrive ready for your warehouse.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



