Stand

On this page you will find pictures, tutorial videos, technical drawings and know-how on how to build a working stand for car engine electronics.

There may be many different ways to to this, but overall layout would be always same.

If you are builiding a stand like this, there will be many possibilities to add/remove some functions, but our design allows to study car engine electronics at the requiered level in vocational education.

Budget

Modern gasoline engine (pref. with turbo) and engine wiring 800.-

Osciloscope and other diagnostic devices 800.-

Battery, battery switch, intelligent battery charger 160.-

Gas tank, petrol pump 120.-

Muffler (pref. with catalytic converter and O2 sensors) 100.-

Radiator with hoses and expansion tank 80.-

Same vehicle instrument cluster 40.-

Steel tubings (ca 60 kg) 60.-

Wheels with brakes 4pc 40.-

Plexiglass/plastic 30.-

Wires (ca 30 m) 30.-

Banana connections (80pc) 80.-

Additional materials (paint, nuts, polts, fasteners etc.) 80.-

Additional materials for every stand:

Drill set 80.-
Vernier calliper 40.-
Mechanic work lamp 40.-
Measuring tape 20.-
Extension cord 5.-
Working gloves 15.-
Welding materials 20.-
Angle grinder discs 20.-
Protective glasses 5.-
Working clothes 80.-
Security boots 50.-

TOTAL: 2780 .- EUR

Please keep in mind that these are approximate prices. Most of them are purchased as used and therefore prices may vary.

Preparation - purchasing a donor vehicle

For the donor vehicle a damaged Renault Twingo II with a 1,2 litre engine, produced in 2012, was purchased, as it met all the needs for the particular learning stand.

Stage 1 - decreasing the dimensions

In order to convert the vehicle into a suitable learning stand, it has to be decreased in size and access to all the necessary devices needs to be assured. The vehicle needs to be stripped down to the front part without obliterating its functionality. Before removing the rear of the vehicle, necessary preparatory tasks have to be done.

- Remove the security system – airbags, seatbelts, security system’s control unit, alarm system – which is not needed.

- Remove the interior of the vehicle, all bolstering and wiring, which goes to the rear of the vehicle.

- Remove the dashboard, centre console and all unnecessary coverings from the devices.

- Remove the fuel tank, fuel pipe system and the rear brake system.

- Remove the exhaust pipe system and manifold.

- Remove the rear hatch, side doors, front panels, wings and windscreen.

This concludes the preparations for removing the rear of the vehicle. Next the exact places for cutting need to be marked. Here the centre of mass needs to be taken into consideration, so that the engine would not weigh in front of the front axle and it would be suitable to construct the support wheels.

Finally, the cutting will be done: cut through the window and door sills, remove the roof and finally cut the vehicle in half.

Stage 2 - Installation of support wheels, wheel arches, rear hatch and adjustable seating

Cart wheels will be used as support wheels, as the workload does not exceed 150 kg they are durable enough. The wheels will be covered with new sheet iron wheel arches.

The rear hatch will become the rear wall of the stand, where all the vehicle rear devices can be attached, for example:

1. lights

2. locking system for the hatch

3. rear windscreen wiper

The hatch is attached on hinges so that its position could be modified for comfortable access when testing electrical devices. The position can be fixed with the length of the installed chain. The upper position is fixed with a locking mechanism and support beam installed for strength, on which the additional fixing bolt attaches. In order for comfort during diagnostics an adjustable seat will be installed as well.

Stage 3 - Preparation of the vehicle front

In order to preserve the functionality of the stand and to identify the deficits, all the components need to be identified before disassembly. All removals need to be marked and the whole systems working condition systemically tested by reading error codes and starting the engine. In case of problems it is possible to retake previous steps.

The whole electric system needs organizing in order to assure comfortable usage, optimization of the build and visually pleasing design. From the front panel the part which gives the stand its visual design will be preserved, this part will help to identify the donor vehicles origin and will not interrupt the installation of the front devices or block the access to their electrical signals.

Stage 4 - Installation of devices from the doors and interior to the stand

The devices which were placed in the doors (door locks, window mechanisms, control switches, mirrors) will be installed on the sides where it is comfortable to check their functionality. All the devices from the interior panel will be attached in the same area with suitable resources. The interior lighting will light the engine compartment.

With these task the main assembly of the stand devices will be completed. Now the working order of all the devices need to checked, the hanging wires need to be attached and all necessary parts isolated so that the wiring would not obstruct anyone using the stand.

Stage 5 - construction and installation of the fuel tank

Instead of the original fuel tank a more suitable one will be made from a fuel tank of a boat. For this the fuel pump will be cut along the modules attachment from the old fuel tank and connected to the new tank. Instead of fuel pipes fuel hoses will be used and the tank will be attached to the stand with straps.

Stage 6 - connecting engine electronics sensor signals to the control sockets

Now work on the engine electronics part can be started. All the sensor signals of engine electronics need to be connected to banana type control connectors, in order to check sensor work directly from the sensor connecting terminal so that other errors could be eliminated.

Manufacturers have installed protective covering and insulating tape around the wiring in order to assure durability. The identification and detangling is a very time consuming process which cannot be rushes because the wiring should not be damaged. All tasks that are connected with handling electrical connections are done when the negative battery terminal has been removed. After the installation on every connection the stand needs to be started and the signal needs to be checked with an oscilloscope in order to avoid problems in the future. The wiring needs to be organized in a way which allows to properly insulate them after all the connection have been made. From the sensors and plugs approximately 5cm will be left uninsulated, in order to see the colours of the wires, which are connected with the electrical schemes. In addition, this would allow to measure the current with clamp meters.

Stage 7 - Construction and installation of the break-out box

The break-out box is needed in order to check the work of sensors and actuator devices in real time using the electrical schemes of the particular vehicle. To check these an oscilloscope (Adac 3000), clamp meters and multimeters are used. The measuring adapter has to be constructed as a link between the engines control unit and wiring. In addition, a new and logical division of terminals needs to be created in the control panel. For creating the break-out box various materials will be used – plywood, isolator sheet, transparent plastic as the lid, three colours of banana connectors (because the engine control unit has three plugs A, B and C).

On the stand a base table will be constructed for the break-out box, where necessary tools could be placed when needed. Taking excerpts from the control unit is a task that requires the most attention and accuracy. Every terminal has its own marker and has to find the correct place in the box. Soldering is the only method that will be used in order to guarantee good connectivity and durability. Isolation will be done with fusing and isolation tape. For extensions either an equivalent or bigger wire will be used. Isolation colours need to be preserved so that everything would cohere with the electrical scheme of the vehicle. The terminals will be marked according to the electrical schemes. The control unit (ECM) will also receive a new position – attached to the work table.

Stage 8 - Installation of an adjustable computer desk

For a more comfortable working experience an adjustable computer desk will be constructed, on which a laptop and other tools could be places. The desk will be covered with a non-slippery rubber and the edges with a rubbery round material.

The desk area will provide a comfortable way of doing the tasks from all sides of the stand. From the driver’s position it is suitable to do the tasks with signals from the OBD plug. At the front of the stand it is possible to comfortably test the work of the sensors and devices in the engine compartment by using the break-out box for measuring the signals.

Stage 9 - Implementation of technical safety tasks

It is important to assure safety when working with the stand. For this all sharp edges, and unnecessary former connections will be removed or covered with rubber sealing. All wires will be fixed and attached in appropriate places. As the stand is driveable, the brakes need to be checked and the running engine has to have the stop possibility. For this two emergency switches will be installed on the stand: black and red.

Stage 10 - Installation of the electronic error switch box

The box for the errors administered to the electronics could be made out of a trunk. This allows for a comfortable installation of the switch panel and as the teacher is the only user of the box, it allows for the box to be locked. All of the switches and positions are marked with numbers.

The box could be positioned next to the driver’s seat, which would be a reasonable distance from the wiring and would allow accessibility to the Instructions of errors which is placed in the lid of the box.

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