Starter Relay Solenoid Switch - RM09033
Honda TRX 90 / 400 / 450, 350 / 420 Rancher, 450ER ES, 500 Fourtrax Foreman and 650 / 680 Rincon 1990-2024
This is a brand new starter relay solenoid switch covering a very wide span of the Honda TRX range, from the little TRX 90 through the Rancher and Fourtrax Foreman workhorses up to the 680 Rincon. The solenoid is the heavy-duty switch that stands between the battery and the starter motor. Press the start button and a small current energises the solenoid coil, which snaps a pair of high-current contacts closed and hands the full battery load to the starter. Without it, that current would have to run through the handlebar switch and its thin wiring, which is why the solenoid takes the punishment and why it is one of the parts that eventually wears out.
This unit is a direct replacement built to the factory pattern: 52 mm wide by 52 mm long by 39 mm high, with two terminals for the heavy cables, two wires and a single plug for the trigger circuit. It goes back into the standard mounting with the existing battery and starter cables onto its studs, so there is no rewiring, no drilling and no bracket work. The quality exceeds the OEM equipment and all products shipped are tested. It cross-references eight Honda part numbers, listed in full below.
Key Features
- Brand new starter relay solenoid switch
- Direct replacement to your original unit
- Two heavy-duty terminals plus a plugged trigger circuit
- Factory-pattern 52 x 52 x 39 mm body
- Cross-references eight Honda OEM numbers
- Quality exceeds the OEM equipment
- All products shipped are tested
Technical Specs
| Specification |
Detail |
| Part Number |
RM09033 |
| Width |
52 mm |
| Length |
52 mm |
| Height |
39 mm |
| Number of Terminals |
2 |
| Number of Wires |
2 |
| Number of Plugs |
1 |
Vehicle Fitment Guide
Years shown are the overall coverage span for this part. Please confirm against the OEM part number on your original unit before ordering.
| Make & Model |
Years |
| Honda TRX 90 |
1990-2024 |
| Honda TRX 350 Rancher |
1990-2024 |
| Honda TRX 400 |
1990-2024 |
| Honda TRX 420 Rancher |
1990-2024 |
| Honda TRX 450 |
1990-2024 |
| Honda TRX 450ER ES |
1990-2024 |
| Honda TRX 500 Fourtrax Foreman |
1990-2024 |
| Honda TRX 650 Rincon |
1990-2024 |
| Honda TRX 680 Rincon |
1990-2024 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 35850-HF1-670 |
Honda |
| 35850-HM7-000 |
Honda |
| 35850-HN8-003 |
Honda |
| 35850-HN7-003 |
Honda |
| 35850-HN7-000 |
Honda |
| 35850-HP5-600 |
Honda |
| 35850-HN2-A01 |
Honda |
| 35850-HP1-601 |
Honda |
Frequently Asked Questions
Will this fit without modification?
Yes. It is a direct replacement to your original unit on the listed Honda TRX models. The 52 x 52 x 39 mm body matches the factory part, the two studs take your existing battery and starter cables, and the trigger circuit connects through the standard plug. No cutting, drilling or rewiring is needed.
What is included?
You receive the starter relay solenoid switch with its two wires and plug for the trigger circuit. The heavy battery and starter cables, along with the rubber mounting boot on your machine, are reused.
How do I know the old solenoid has failed?
The classic sign is one sharp click from the solenoid when you press the start button, with the starter motor not turning. You may also get no click at all, or a starter that engages only every third or fourth attempt. Before condemning it, check the battery is fully charged and clean both cable ends at the solenoid studs, because a corroded or loose connection produces the same symptoms and is far cheaper to fix.
Does one solenoid really cover the whole TRX range?
Honda used this solenoid pattern very widely across the TRX line, which is why the cross reference table carries eight different 35850- numbers. Fitment is model specific though, so the safest check before ordering is to read the number printed on the solenoid currently fitted to your quad and match it against the table above.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
