STARTING CONTACTOR FOR FIAT AND NEW HOLLAND " CASE IH " 5129862

Start contactor for tractors Case IH, , Fiat and New Holland

The start contactor Ref. 5129862 is a key-operated switch designed to turn on the power and control the start-up of various tractors. This version can be identified by its flat-blade connectors. It is used primarily on tractors Case IH the AVJ, JX, and VJ series, as well as several models Fiat, , Someca and New Holland included in the compatibility list.

The role of this key switch on the tractor

This part is located in the driver's cab and is used to activate the starting circuit with the key. On a tractor, this type of switch is used to control the electrical power supply according to the positions specified by the original assembly, and then to engage the starter at the appropriate time. When replacing this part, the goal is to ensure that the control system is compatible with the wiring harness already installed on the machine.

This is an electrical control unit: to replace it correctly, you must therefore identify the correct part number and connection type, without making any assumptions about specifications that have not been confirmed for your tractor.

Useful guidelines for identifying part number 5129862

The first thing to check is the part numbers. This part should match the reference numbers 5129862, , 5146155, , 4998108, , 5112124 and 5123727. These part numbers are useful for matching your old contactor to an equivalent model currently in use.

The second important indicator is the presence of flat-blade connections. This detail helps distinguish this version from other starter contactors that look similar. If your old contactor shows signs of wear, has a faulty connection, or the key turns unevenly, note the part number on the removed part and also compare the general layout of the connections with your wiring harness.

Applicable Tractor Applications

This contactor is documented for several families of agricultural tractors.

• Case IH : TV series AVJ, , JX and VJ, including AVJ55, AVJ60, AVJ70, JX55 through JX95, VJ60, VJ70 and VJ80.
• Fiat and Someca : Many models from the 46, 66, 88, 90, 93, and 94 series, as well as several 1180, 1380, 1580, 1880, and Someca tractors listed in the detailed compatibility chart.
• New Holland : models TD4020F, , TD4030F, , TD4040F, families TD5, , TD5010 through TD5050, versions TD D Plus and tractors TN65F to TN95F.

The complete list of affected models is included with this document. It allows you to confirm the exact application before installation, especially when there are several similar contactors within the same series.

Before choosing this contactor

A starter contactor is selected first based on the part number, then on the connection type. For this version, use on a tractor Case IH, , Fiat or New Holland must be verified using the exact machine model. If the tractor has already been modified or repaired, check the existing switch before placing an order.

To ensure you make the right choice, start with the part number listed on the removed part and the exact tractor model.

Compatibility by Brand and Series

Case · Tractor

• AVJ55
• AVJ60
• AVJ70
• JX55
• JX60
• JX65
• JX70
• JX75
• JX80
• JX85
• JX90
• JX95
• VJ60
• VJ70
• VJ80

Fiat · Tractor

• 100-90
• 100-90DT
• 110-90
• 110-90DT
• 115-55
• 115-90
• 115-90DT
• 1180
• 1180DT
• 130-90
• 130-90DT
• 1380
• 1380DT
• 140-90
• 140-90DT
• 1580
• 1580DT
• 160-90
• 160-90DT
• 180-90
• 180-90DT
• 1880
• 1,880 DT
• 45–66
• 45-66DT
• 45–66 V
• 50–66
• 50-66DT
• 50-66S
• 55-46
• 55-46DT
• 55–66
• 55-66DT LP
• 55–88
• 55-88DT
• 60-46
• 60-46DT
• 60–66
• 60-66DT
• 60–66F
• 60-66FDT
• 60-66LP
• 60-66LPDT
• 60-66S
• 60-66SDT
• 60–90
• 60–93
• 60-93DT
• 60–94
• 65-46
• 65-46DT
• 65–66
• 65-66DT
• 65–90
• 65–90DT
• 65–93
• 65-93DT
• 65–94
• 65-94DT
• 70-56DT
• 70-56L
• 70–66
• 70-66DT
• 70-66F
• 70-66LP
• 70–90
• 70–90 DT
• 72–93
• 72-93DT
• 72–94
• 72-94DT
• 80-66
• 80-66DT
• 80-66F
• 80–90
• 80–90 DT
• 82–93
• 82-93DT
• 82–94
• 82-94DT
• 85–90
• 85–90 DT
• 88–93
• 88-93DT
• 88–94
• 88-94DT
• 90-90
• 90-90DT
• Someca 446
• Someca 446DT
• Someca 466
• Someca 466DT
• Someca 566
• Someca 580
• Someca 666
• Someca 670
• Someca 670DT
• Someca 680
• Someca 766
• Someca 780
• Someca 880
• Someca 980

New Holland · Tractor

• TD4020F
• TD4030F
• TD4040F
• TD5.100
• TD5.105
• TD5.110
• TD5.115
• TD5.65
• TD5.75
• TD5.80
• TD5.85
• TD5.90
• TD5.95
• TD5010
• TD5020
• TD5030
• TD5040
• TD5050
• TD60D Plus
• TD65F
• TD70D Plus
• TD75F
• TD80D Plus
• TD85F
• TD90D Plus
• TD95D Plus
• TN65F
• TN70F
• TN75F
• TN80F
• TN95F

Case IH · AVJ Series

• AVJ55
• AVJ60
• AVJ70

Case IH · JX Series

• JX55
• JX60
• JX65
• JX70
• JX75
• JX80
• JX85
• JX90
• JX95

Case IH · VJ Series

• VJ60
• VJ70
• VJ80

FAQ — Frequently Asked Questions

What is the purpose of this starter relay on a tractor ?

It is used to turn on the power and start the tractor using the key. For this part number, identification is based primarily on a comparison of the numbers 5129862, 5146155, 4998108, 5112124, or 5123727, as well as on the presence of flat-blade connectors.

How can you identify this control contactor ?

The safest approach is to compare the old switch with the part number printed on it, then check the connection type. This version is distinguished by its flat-blade connections. Also check the exact tractor model, as there may be several similar key-operated switches depending on the series.

Is this contactor suitable for tractors? Case IH AVJ, JX, and VJ ?

Yes, it is recommended for Case IH AVJ55, AVJ60, AVJ70, JX55, JX60, JX65, JX70, JX75, JX80, JX85, JX90, JX95, as well as VJ60, VJ70, and VJ80. If the machine has already been repaired, be sure to check the part number stamped on the existing contactor.

Is it also designed for certain tractors? Fiat, Someca, and New Holland ?

Yes, this part number is also listed for many tractors Fiat and Someca, as well as for New Holland TD4020F, TD4030F, TD4040F, TD5, TD5010 through TD5050, and TN65F through TN95F. Verification must be performed on the exact model listed in the compatibility chart and for the specific connection type.

The part numbers and brands of original replacement parts are provided for comparison purposes only. This does not imply that they are original parts.