Cub Cadet 2000 Series - Manual (Page 148)

2000 Series Tractors
142
Relay
Most of the relays used by MTD or Cub Cadet have five
pins. See Figure 7.65.
• Windings: Terminals 1 & 2 are the outer-most of
the row of three small spade terminals. When
one has power and the other is connected to
ground, the relay is energized.
• Normally, a resistance reading between termi-
nals 1&2 will produce a measurement of about
100
Ω. This is the resistance in the windings
around an iron core that energize an electro-
magnet or a solid-state equivalent.
• Terminal 3 is a “Common” connection. It may
be connected to power or ground, depending
on the application. It is the large spade terminal
near the edge of the relay.
• Terminal 4 is the “Normally Closed” contact.
When the relay is not energized, terminal 4 is
connected to terminal 3. When the relay is
energized, this connection breaks. An Ohm
meter should show zero resistance or “0.0
Ω”
between 3 & 4 when the relay is at rest, and it
should read no continuity when the relay is
energized.
• Terminal 5 is the “Normally Open” terminal. It
connects to terminal 3 when the relay is ener-
gized. When 3 & 4 are connected, 3 & 5 are dis-
connected, and vice-versa. An Ohm meter
should show zero resistance, or “0.0
Ω”
between 3 & 4 when the relay is at rest, and it
should read no continuity when the relay is energized.
To test a relay
1. Test for continuity between the common and the NC terminals using a DMM.
2. Test for continuity between the common and the NO terminals using a DMM.
NOTE: There should be continuity with the NC terminal and no continuity for the NO terminal. If the results
vary from this the relay is bad.
3. Apply 12 volts to terminals 1 and 2. This will active the relay.
4. Test for continuity between the common and the NC terminals.
5. Test for continuity between the common and the NO terminals.
NOTE: There should be no continuity with the NC terminal and continuity with the NO terminal. If the results
vary from this, the relay is bad.
NOTE: To test the relay for burned contacts, do a voltage drop test across the relay contacts while the circuit is
being used.
Figure 7.65
Spade 3 Common
Spade 4 N.C.
Spade 2 Windings
Spade 1 Windings
Spade 5 N.O.
O O
O O
O O
3 4
5
1 2
Inset:
Circuit diagram’
of relay, printed on the
side of some relays