Gauge FAQ

Frequently asked questions ...


1. Will the sensors on my engine work with ETB gauges?

Unfortunately, the short answer is: probably not!

Temperature Gauges:
You will need our own temperature sensor in order for the ETB temperature gauge to read correctly. The only exception to this is if you have a 150°C rated VDO (aftermarket) temperature sensor. Thread adapters are available to match various engines.

Oil Pressure Gauges:
Most engines do not have an oil pressure sensor to supply an oil pressure gauge. Instead an engine usually has a low oil pressure switch mounted on the side of the engine block. This is a simple switch that illuminates a dashboard mounted warning light should oil pressure drop below a certain level. It is not able to supply an oil pressure gauge with a suitable signal. Therefore you will require an ETB oil pressure sensor to match our gauge. ETB pressure sensors have a warning light switch built in, so the oil pressure sensor is mounted in place of the old pressure switch. Thread adapters are available to match various engines.

Speedometer Sensors:
Many OEM gearbox speedometer sensors will work well with an ETB electronic programmable speedometer provided that it is not also supplying an engine management system (where fitted) with a speed signal. For further information please see the section concerning speedometer sensor set-up.

Fuel Level Gauges:
ETB manufactures 3 types of fuel gauges.

The first type is matched to our standard, 6-hole, top-mount float-arm sensor. This sensor is calibrated to provide an electrical resistance of 260 Ohms at empty and 20 Ohms at full. This calibration range is similar to early Smith's type fuel level senders, as well as some Ford fuel senders (most commonly 1982-1986 Ford Sierra hatchback / saloon).

The best way to check whether your existing fuel level sender will work with an ETB fuel gauge is to measure the resistance range of the sender unit. To do this, you need to disconnect any wires connected to the sender unit and remove the sender from the fuel tank (taking great care if there is any fuel left in the tank). Using a multimeter that can measure resistance in Ohms (Ω), connect one probe to earth and the other to the connector on the fuel sender and note the resistance reading with the float at empty (lowest position) and at full (highest position).
If the reading is approximately 260 Ohms at empty and 20 Ohms at full, it will work reasonably well with an ETB fuel gauge.


These sensors were not designed to work with the modern ETB air-core movements, but with old bi-metallic strip gauge movements. Therefore, although empty and full will be correctly indicated on the gauge, mid-range indication will read incorrectly. This is because ETB gauges expect a relatively linear change in resistance as fuel level changes, whereas the older Smith's type / Ford type are not linear - this basically means that fuel will appear to decrease very rapidly from reading full for the first two-thirds of gauge pointer movement and then slow considerably when the pointer nears empty.

The second type of ETB Fuel gauge has a range of 3 Ohms at empty to 180 Ohms at full. This type will match certain VDO lever-arm type fuel senders.

The third type of ETB fuel gauge has a range of between 60 & 90 ohms at empty to 0.5 Ohms at full. These are made specifically to match VDO dip-pipe fuel senders and if you not ordering the VDO sender at the same time or already have one, then you need to inform us of the VDO dip-tube sender length in mm.

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2. Will ETB sensors match the threads on my engine?

All ETB sensors (temperature and oil pressure) unless otherwise stated have a 1/8"NPTF (27) tapered thread. ETB holds stock of a great variety of brass thread adapters in order to match the vast majority of engines in existence.

We make our sensors to match this thread type because it is: a) small and it is easiest to increase in thread size to fit a larger hole rather than reducing size, and b) the most common thread size.

If you tell us the make, model and year of the donor vehicle when placing your order, we can tell you what thread adapters you might need.

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3. Will the tachometer work with my vehicle's ECU (Electronic Control Unit)?

Our standard tachometers normally work by taking a signal either from the negative side of the Ignition Coil or from the ECU.

Unfortunately, there is no "standard" signal output from ECU's and they can vary greatly from manufacturer to manufacturer, however our Mk3 tachometers will work with the majority of them and can be calibrated by the user accordingly. If there is no output from the ECU, then the RPM signal can always be taken from a coil pack or  an individual coil (if it is a coil per cylinder setup).


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4. Will the fuel sender fit my fuel tank?

Yes, if you are prepared to cut a 40mm diameter hole in the top of your tank and drill 6 mounting holes!  ETB's standard 6-hole, top-mount fuel sender is 290mm from the top of the tank to the bottom of the float unit. It is a simple float -arm sender that can be shortened to length as required.

Alternative sensors are available including VDO Dip-tube-type fuel senders that are manufactured in set lengths. Always ensure that you have that the gauge and sensor are matched.  

Please note that ETB fuel senders do not incorporate fuel feed or return pipes.

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6. Are ETB instruments IVA compliant?

YES. The outer bezels were specifically designed to pass IVA. Of course you must ensure that your speedometer is calibrated to match your vehicle.

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7. I want to buy an electronic speedometer.
Will I need a sensor and what is the best / easiest sensor set-up?

You will need to provide the speedometer with a signal related to the vehicle's speed. Some OEM gearboxes have electronic sensors that can provide our speedometer with a suitable pulse signal of which the vast majority are compatible with our speedometers.

If you do not have a gearbox sensor, you have several other options:-

i. M8 Speed Sensor (340 002) and Bolt-Heads or Gear Teeth (e.g. ABS reluctor ring)
The 8mm diameter sensor is designed to detect ferrous objects as they pass the end of the sensor such as bolt heads or gear teeth. Flat bolt heads on the inner part of the brake disc (front wheel hub) is one possible location (Westfield Sports Cars use our sensor in this way), or alternatively bolt heads that fix the differential flange and pro-shaft flange together. A disc is also available that fits fits between these two flanges with 4 teeth for this purpose.  

ii. Heavy Duty Sensor and 15 Hole Disc Combination
This entails mounting our speedometer disc (150mm diameter with 15 holes on a 130mm P.C.D.) between the prop-shaft flange and differential flange (i.e. sandwiched between the two flanges). You must them fabricate a bracket to hold the sensor in place such that it points at the centre of these perimeter holes as the disc rotates. The sensor creates a pulse for the speedometer each time the metal between each hole passes in front of the sensor head.
More difficult to set-up than sensor and magnet combination, but more reliable than using bolt heads.

iii. Heavy duty sensor and bolt heads
You can also use the heavy duty sensor in conjunction with ferrous bolt heads. These could be bolt heads on a front hub or those connecting the prop-shaft to the differential for example. (Westfield for example sometimes use bolts on the driveshaft coupling). The bolt heads must be ferrous (i.e. have an iron content and attract a magnet), and have a flat surface. (The side wall of a allen-key bolt would do)
Again, you are required to make a bracket to hold the sensor in place. This set-up is reliable if undertaken correctly, but is more difficult than using the light duty sensor and magnet combination.

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8. Where do I fit my oil temperature sensor?

The easiest position is generally in place of the oil drain / sump plug by using an appropriate thread adapter.  If the plug is located on the bottom of the sump, or should ground clearance be a problem, you may need to find an alternative port on the engine block accessing the oil gallery to mount the sensor. As an example, Ford Zetecs generally have a 2nd 1/4"NPT blanking plug on the same side as the pressure switch that can be used for oil temperature.

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9. What is best: Ammeter or Voltmeter?

Ammeters measure electrical current (in Amperes) flowing through a circuit and therefore are wired in series with the load. They are useful when using a dynamo based charging system, as they can warn the driver (for example) of negative charging conditions. However, because ammeters are connected in series with the circuit being measured, it requires that current flow (both positive and negative) passes through the ammeter itself. This means that heavy duty cables are required to connect to the ammeter in order to withstand the large electrical current being passed through it.

If using an alternator based electrical system, the electrical current flow tends to higher than that of a dynamo, and therefore the greater the current flow the larger the cables need to be. Modern alternators tend to be connected to an ignition warning light that illuminates should the charging current become too low and thus reducing the need to constantly monitor the charging current. However they are a useful, instant method of measuring current drain incurred from various loads (e.g. headlights).

Voltmeters measure electrical "pressure" and are connected across a circuit. This means that wiring is very simple and standard automotive wire required for the other gauges can be used. Voltmeters will provide you with the current status of the car battery, as well as indicating charging problems (by a gradual voltage drop indicated on the gauge).

In general, if you are concerned about electrical wiring, ETB would recommend a voltmeter rather than an ammeter.

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10. What size holes do I need to cut in my dashboard in order to fit ETB gauges?

The size of our gauges denotes the outside diameter of the main body or casing of the instrument. In other words, a 52mm gauge has a 52mm diameter casing. This means that the hole required in the dashboard needs to be a little bigger:-
52mm Gauges - 53 to 54mm diameter hole
80mm Gauges - 81 to 82mm diameter hole
100mm Gauges - 101 to 102mm diameter hole

The diameter of the outer bezel of each gauge is larger than the casing diameter. The overlap of this bezel is approximately as follows:-
52mm Gauges - Outer Bezel Diameter = 56.5mm
80mm Gauges - Outer Bezel Diameter = 85mm
100mm Gauges - Outer Bezel Diameter = 105mm

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11.  How do I wire up my gauges?

Please refer to 'Gauge Wiring Diagrams' under the Technical Info Menu  which list appropriate PDF files for download.

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12. What colour instrument dials do you sell and what colour pointers can I have?

Please see the various ranges available under ETB gauges. We can do other dial colours and pointers colours as required at extra cost. 

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13.  What outer bezels do you make?

We currently make black, chrome, or anodised aluminium. Our bezels are all rounded in style and IVA compliant.

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14. How can I order and how do I pay?

You can online using this webshop - we accept PayPal and Card payments (you do not need a PayPal account).

Alternatively you can order your instruments by either telephoning ETB Instruments on +44 (0) 1702 601055 or by faxing us on +44 (0)1702 601056.

We accept the following cards:-
Visa, VISA Debit, MasterCard, Maestro (Switch), Solo or American Express.

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15. Do you repair or re-calibrate instruments in general?

No, only ETB Instruments' own range.

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