Overview
Inline diode, 3 amp, 1000 PIV. HydraMaster part number 000-135-051, listed as Regulator, 3 Amp 1000 PIV Diode.
It is a one-way valve for electricity. In a truckmount it is normally there to protect the control circuit from the reverse voltage spike that a solenoid or relay coil produces when it switches off — a spike that will otherwise find its way into whatever else is on that circuit.
What it fits
HydraMaster's suggested spares schedule lists it against six machines:
- Boxxer 421
- Boxxer 427
- CDS 4.6 / CDS 4.8
- CTS450
- MAXX 450D / 470D
- SpitFire 3.2
It is also named in the parts lists of:
- Boxxer 318HP — Regulator, 3 Amp 1000 PIV Diode, 1 fitted
- SpitFire 3.2 and SpitFire 4.0 — listed as Diode, 1 each
- Crossfire 3.7 and Crossfire 4.2 — listed as Diode, 1 each
That is nine machines, which makes this one of the most widely shared electrical components in the HydraMaster range.
Specifications
- Forward current: 3 A
- Peak inverse voltage: 1000 PIV
- Style: inline
Fitting advice
Polarity matters. A diode fitted the wrong way round will either do nothing or short the circuit it was meant to protect. Note the orientation and the band on the body before you remove the old one, and take a photo.
Isolate the circuit before you start. Diodes are usually in the loom near the component they protect, and there is rarely much room to work.
A failed diode does not always look failed. If a solenoid circuit has been misbehaving — a relay chattering, a control board doing something inexplicable, a switch that works intermittently — check the diode before you replace anything expensive. It is the cheapest part in that circuit and one of the most common causes.
Related parts
Frequently asked questions
Which way round does it go?
The same way as the one you removed. Photograph it before you take it out. If it is already gone, do not guess — send us a photo of the circuit and we will help.
Can I use a generic diode of the same rating?
Electrically an equivalent part will work. HydraMaster specify this one, and on a machine under warranty that matters.
How do I test it?
With a multimeter on diode range: it should conduct one way and not the other. A diode that conducts both ways or neither way is finished.
How many are fitted?
Typically one, but it depends on the machine. Check the wiring diagram for your model.
Chasing an electrical fault? Tell us the machine and the symptom — a cheap diode is very often the answer and we would rather you checked it before ordering a control board.
