41. The Electric Wiring

After the motor was running by using a temporarily wiring it was time to think about the real wiring.
I stated in one of the first posts, that my daily job is electronics engeneering, so I set the level for the quality of that task quite high.
What means "high"?

You have a close look to the wiring and you see, if it was treated by a amateur or a skilled person has done some changes to it.
The overall health condition of the wiring hasness can be seen after it is laying before you...
A very important part is: Do you have a plan and fits this plan to the real harness.

All this together with a little bit of stomach feeling and you know what you have to do...


The Mantula is a 50:50 decission.
The wiring harness looks realy good. Only in the engine bay I found some amteur treatments at the lights. Behind the dash board it is good, too.
The LHD exchange forces me to modify the wiring a little.
A circuit diagram I got the John ( Thank you...!) was for the Mantula, but sadly the real wiring fitted only for 80% to this plan.
And there are some new ideas in my head about the functions...


First I started to analyse in detail what I have.

Here the horrible results:
There are some wires, which run directly form the battery through the car. If there would be a short circuit, the wohle car can burn down.
I did not find a main fuse. From all the fuses only the half of them was in use.
Most of the ignition switched loads take their current over the ignition switch - not only the relay current.

So I decided to do a partly new wiring. Partly only, cause the wiring of the steering columns and the harness to the trunk will be reused - but the function of the cables will change.
NEW will be
- the complete motor bay harness,
- the high power cables ( alternator, solenoid, starter,...)
- the cables for the gauges power and ilumination
- the gauges will be illuminated by adjustable brigthness LEDs
- the main light switch will move it position to all the other switches (the break fail test has to leave...)
- the radio will follow the break fail test switch
- the two speakers on the shelf will stay and a amplifier with Bluetooth "line in" will join
- the flip front will get a connector, so it can be unmounted easy
- the number of cables in the motor bay can be reduced to the half (~20) of the original number (~40 !!)

You see, a big task.

I started with designing a new circuit diagram. I have choosen TinyCAD, a free and easy tool.
I used a different style to draw the diagrams. It is not as they are wired - it is arranged like the current flows.
Have a look:

Some items like the gauges are missing - it is an early state...

I started with the gauges. Remove the bezels to open the case was easy. I thought, I will buy new chrome bezels, but for the speedo and the tacho I did not get the fitting size. At the moment I try to polish them. If it looks OK good - if not I will chrome plating them.
LEDs are a 5m band  and you can cut it every 3 LEDs. White color inside will give a smooth light. Looks good at night.
With the small PCB in front you can dim the LEDs. It is a cheap China electronic for 2,56€ and it works perfect.

 

To pass the bulkhead in a nice way with the wires I made this alu part. On the right side is enough space for the speedo spindle, the window washer tube, bowden cable for the circuit breaker,...

Actually it looks like this: