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[Datsun 1200 encyclopedia]

B210 Tachometer

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Category: Datsun B210

<-- back to B210 Gauges

Tachometer (rev counter) for Datsun B210.



Datsun B210 tachometer (24855-H5100)

Datsun 720 tachometer vs Datsun B210 tachometer06412d67.jpg
720 box says "720 タコ" and "TACO 24855-03W00"
B210 box label says "24855-H6100 METER"


The plastic box (housing) that contains the tacho is the opposite way around. i.e, a mirror image. The bottom tab is offset to one side. Apparently the gauge mechanism differs too since the wires are different.

when viewed from the front
* LHD offset to the left of center
* RHD offset to the right of centre

Right-Hand Drive
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Left-Hand Drive

One-Wire vs Two-Wire

On a factory tachometer, the BW wire (Black wire with White stripe) is the signal wire. This wiring only matters if you wish to use the factory wiring harness.

  • RHD tachometers use a induction-loop signal wire (two BW wire ends come out of the tacho) — like the B110 unit
  • LHD tachs use a voltage sense wire (one BW wire) like most Datsun tachs starting in the mid-1970s

A one wire tach has ONE black/white wire not two (it also has the red wire and black wire that plug into the instrument circuit board ). I think all RHD 120Y wiring harnesses expect a two-wire tach ... Possibly you can adapt it either by soldering another black/white wire onto the tach (there is a spot), or just putting t-intersection in where the black/white wires connect on your wiring harness so that the tach is connected and the ignition circuit is still closed.

Two-wire RHD (two BW wires coming out of case)
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One-wire LHD (single BW or BG wire coming out)
12134.jpgAlbum click to view

Wiring RHD

The tachometer is wired in series with the coil feed wire. There are two connectors that you pull apart behind the dash and plug the the tach wires into the loop, plus it has an IGN+ wire.

RHD Wiring discussion: POST 120y tacho trigger
28064.jpgAlbum click to view

Wiring LHD

The tachometer is wired to the coil negative terminal. All North America B210s have the tachometer wiring right there in the dash. So no cutting needed, and no new wires need to be run out to the coil.
28061.jpgAlbum click to view 28062.jpgAlbum click to view

Just make sure the tach you buy has the adapter harness (mini-harness) included. It is all the red wires and includes two lamp sockets and a six-pin connector.
174_615c0e2bc2d6f.jpgPost click for topic 174_615c0e07056fa.jpgPost click for topic

6-pin rectangle connector
* with divider & two slanted-corners
RY  B  wire colors
----- [divider]

BG  n/c TACH:BG n/c
-----   [divider]
Early (BW wire) one-wire (single BW wire coming out). B wire is grounded to the metal case28065.jpgAlbum click to view
B210 tach LHD USA

EARLY USA bullet connectors
* B  ground (Black wire)
* R  IGN+   (Red wire)
* BW signal (Black wire with White stripe)

Late (BG wire) one-wire (single BG wire coming out)
174_6156fe4f7ed79.jpgPost click for topic

Used tachs may or may not come with the Tachometer Harness, which is used to plug into the Dash Harness. All B210s have the dash harness tach connector, even cars that didn't originally have a tachometer.

Rear three wires plug into mini-harness (all the red wires)
174_6156fecde70fb.jpgPost click for topic

Tachometer Harness (mini-harness)
* has two black Lamp sockets
* has BW, B, R, RW and RB wires
* 6-pin connector (connects to Dash Harness)
  one pin not connected
* 3 bullet connectors to attach to Tachometer

1976-1978 with the 6-pin connector
BW Coil-
B Ground
BW coil-
B to terminal 'A' on dash
R to terminal 'C' on dash 

The signal wire is brought into the dash wiring even if it didn't come with a tachometer originally.

1974: signal is a single wire in the dash harness
1976: 6-pin connector in the dash harness
1976 CALIFORNIA: signal wire comes from the electronic ignition black
     box (which is under the dash)

7484013842_2fe9d680e5_m.jpg 7484011750_0a6072c4f1_m.jpg 7484010102_010584da15_m.jpg 7484008332_69fd5f595d_m.jpg

174_6156fd2c21b48.jpgPost click for topic 174_6156fd41323bc.jpgPost click for topic

174_6156fe4f7ed79.jpgPost click for topic Tachometer_B210_front.jpg 12133.jpgAlbum click to view


see more photos POST Datsun B210 Tachometer
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Tach-Volt Meter

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Part Numbers

JPN 1973-1975 
rectangle, 2-tab
  (op.) S-all (exc. 4-GX), Van
    24855-H5000 TACHOMETER
    24860-H5000 TACHO. VOLT METER
  S-all (exc. 4-GX), Van
    25007-H5000 MASK-tachometer
round, 2-tab
  24855-H5700 TACHOMETER GX
  24855-H5500 TACHOMETER (op.) K-DX, K-GL
  25007-H5500 MASK-tachometer K-DX
24855-H6200 ASSY-TACHOMETER OP -0775 [BW wire?]
24855-H7200 ASSY-TACHOMETER OP 0875- [BG wire?]

Mask (delete blank/cover) 'DATSUN'

H51	B210GT [RHD GL 4-speed model]
H61	LB210T [LHD 4-speed model]
H62	LB210TRU A13 engine [LHD USA model (1974)]
H72	B210 A12T [twin carb] 

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