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Showing posts with label Electrics. Show all posts
Showing posts with label Electrics. Show all posts

Saturday, 25 April 2026

Plug lead guides for Rover V8

I have made replacement guides for the spark plug leads that attach to the rocker covers on Rover V8 engines.







The screw was seized and the original guides did not come off intact! 



A few measurements and design changes to suit 3D printing and the results work well.


The guides do need supports to print, mainly because of the large overhang for the counterbore.

I bought new machine screws. That was an exercise in working out historic imperial abstract naming conventions! The screws are 3/16"-24tpi x 5/8" long. That's not what you look for to try to buy them. They are called #10 UNC or #10-24. I will never understand the thinking process of naming something with another number to represent the size, instead of using the size!


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Monday, 24 March 2025

In-car reminder binnacle

This evolved out of a comment made about remembering to help out a neighbour on the way home every Monday. I could not resist coming up with a solution.



It was quickly thrown together, over a couple of weekends, using an off the shelf 12V timer that can be set for times and days of the week.



I designed and 3D printed a small binnacle that fits neatly in the corner of a Land Rover Defender TDCi (Puma) dash. It's vaguely in the same style as the rest of the display. I bought some pre-wired 12V LED's and had my choice of colour for the light.


The timer fits on the shelf next to the steering column. As always the longest task was taking the dash apart to find an ignition switched feed and an earth.



I used a Cricut vinyl cutter to make the lettering. It is printed in reverse to apply to some satin translucent plastic sheet. With the light off, the legend is barely visible. The lettering could easily be swapped out.


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Wednesday, 23 August 2023

Defender hazard and indicator light diagnostics

Defender 1984 to 2016

Hazard and Indicator Lights Diagnostics

“Many problems with the indicators are actually faults with the hazard switch.”

 

Wiring Differences

The various models of Land Rover Defenders from 1984 through to 2016 have similar wiring but have slightly different colour wires connected at the hazard switch.

The wiring colours are written as the main colour first with the stripe colour after. As an example, a light green wire with a white stripe would be written as Light Green/White (LGW). A grey (slate) wire with a brown stripe would be written as Slate/Brown (SN).


After 1998, the colour of the ignition feed changes to White/Green and the permanent feed to Purple/Brown.

Operation

To better understand the significant functions, only the indicator operation is described in the following. The panel lighting and tell-tale light functions are not noted here:

When off (not depressed)

 

Indicators can be used.

 

+12V to the flasher relay is supplied from the ignition feed.

The ignition has to be in position two for the indicators to work from the column controls.

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+12V ignition, Dark Green or White/Green, depending on the model year, is connected to the Light Green wire to the flasher unit.

 

When on (depressed)

 

Hazard lights in use.

 

+12V permanent feed is connected to the flasher unit.

The return from the flasher is connected to both the left-hand and right-hand side indicators.

Both sides indicators will flash.

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Permanent +12V Purple or Purple/Brown wire is connected to the Light Green wire to the flasher unit.

The Light Green/Brown return wire from the flasher unit is connected to both the Green/Red and Green/White feeds to the indicator lamps.

 

 

Diagnostics

I like to make up a test wire using an inline fuse. This is to avoid mistakes accidentally shorting out a live to earth. A 5A fuse is suggested. It needs to be less than 10Amp to avoid the fuse box fuse blowing first.

Most indicator faults can be diagnosed via the hazard switch connector.

To Test

Method

Expected Result

Indicator wiring

 

At the hazard switch connector.

Connect the permanent live, Purple or Purple/Brown, to the Left and Right indicator wires, in turn.

Left is Green/Red

Right is Green/White

 

The indicators on one side would illuminate. Not flashing.

 

Flasher unit and indicator controls

 

At the hazard switch connector.

Connect the permanent live, Purple or Purple/Brown, to the Light Green flasher feed.

 

Operate the indicator stalk switches.

 

The appropriate indicators should flash.

 

Ignition live feed

 

At the hazard switch connector.

Repeat the above two operations using the ignition feed Green or White/Green wire, in place of the Purple wire.

The ignition switch must be in position two.

 

Same results as above.

Indicator stalk switches

 

At the indicator stalk pins.

Bridge the Light Green/Brown common wire from the flasher to the indicator wires, in turn:

Left is Green/Red

Right is Green/White

 

The appropriate indicators should flash.

 


Just in-case anyone notices. The photos are from a 1998 300TDi re-wired to use the switches from a newer 2002 onwards TDCi.

Troubleshooting

Bridging any of the wires at the connector works but using the switch fails.

 

Clean the connector pins on both the connector and out the back of the switch.

 

If the above fails to resolve the issue, it will be necessary to replace the switch.

 

Either bridging of the permanent or ignition wire tests fail.

 

Check the appropriate fuse.

 

The indicator lamps illuminate when connected to a live but do not work through the flasher unit.

 

Remove the flasher unit from its socket and clean the pins.

 

If the above fails to resolve the issue, it will be necessary to replace the flasher unit.

 

Cleaning Connector Pins

This can be done with a pencil rubber or more commonly with fine sandpaper. A needle file can be useful to get into confined spaces.

Where the electrical interface is inaccessible, a chemical contact cleaner can be used, however this often also needs the connector to be inserted and removed a few times to assist the cleaning process.

If the connector pins do not hold tightly, small, pointed nose pliers can sometimes be used to gently close up the female portion of the connector pins.

 

Fuses

Ignoring the main fuses and links because there would be other symptoms if they had blown.

Up to 1998

300TDi

 

Permanent Feed, Purple – Central interior fuse box Fuse 1 (15A)

Ignition lighting feed, Green – Central interior fuse box Fuse 3 (15A)

 

1999 to 2001

Early TD5

 

Permanent Feed, Purple/Brown – Central interior fuse box Fuse 31 (15A)

Ignition lighting feed, White/Green – Central interior fuse box Fuse 21 (10A)

 

2002 to 2016

Late TD5
TDCi Puma

 

Permanent Feed, Purple/Brown – Central interior fuse box Fuse 31 (15A)

Ignition lighting feed, White/Green – Central interior fuse box Fuse 21 (10A)

 

 

Switch Types

Defender

1983 to 2001

TD, 200TDi, 300TDi and early TD5

YUF101490 Lucas switch

 







Defender

2002 to 2016

Late TD5 and TDCi Puma

YUG000180LNF

 

 





Freelander

1996 to 2002

YUG102220

 


The early Freelander hazard switch body is the same as the late Defender. It uses the same wiring and connector but the key cap is different.



In the event that a Defender hazard switch is not available, that era Freelander switch can be used as an alternative. In order to make it fit the dash panel, the key cap needs to be carefully removed and swapped over with the Defender key cap. It is held on by two plastic clips, one top and one bottom.



 

 

I'll add to this if I discover any more tips.

I only have direct experience of a 1998 300TDi and a 2009 TDCi. All other information is taken from manuals and third-hand information. There are likely to be exceptions and some cars, like my own, will have been modified.


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Monday, 29 August 2022

Custom motorcycle wiring harness

I have done a lot of electrical work on cars but this is my first time connecting up anything for a motorbike.


Dean has been building a custom motorcycle, pretty much from scratch. The frame and engine were once from different Yamaha's and Dean has adjusted the frame to his taste and assembled it with all the components to make a bike of his design.

He wanted the wires to be tidy so I've made up a complete harness.

I've started with the circuit diagram from a similar era Yamaha, which I had to understand and in the process correct. The engine is a 1985 to 1989 Yamaha XT600 which is similar to the XT550 of the same era.




From that circuit I created my own diagrams, specific to Dean's bike and then added a harness layout for them. Once that was all worked out and I was happy with it...




I proceeded to make up the harness. I've used braided casing, cloth wrap and heat shrink tubing for a tidy job.




It only took a couple of days, on and off, then we were able to fit it to the bike and test it.

It did not go to plan and a bit of investigation was needed. The ignition switch was faulty, so with that bypassed, the harness worked as intended. There was also a slight fault on the connector to the tail light which had a bent pin, easily fixed.

The run for the top tube is a little longer than it needs to be but the whole thing is discretely fitted to the frame.

As a bonus, Dean has a near complete electrical manual for his custom motorcycle.



Download:

Updated July 2023 (revised cable run lengths and test details for some of the components.)

Dean's motorcycle electrical manual (PDF)

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Thursday, 3 March 2022

Defender 300TDi heated seats

This is the second time I've added heated seats to Fender. This time I've done what I think is a tidier job.

Fender is a 1998, 300TDi, so there was no factory fit heated seats option. As usual, I've had to work out my own wiring. There is a convenient feed for air conditioning, which I've used for the heated seats.


It's not very many week ago that I fitted the heated seat wiring to our TDCi Defender, Thunder Truck. 


As then, I've fitted relays. Land Rover wire their heated seats directly via the switches. I am unsure of the rating of the switches and the after-market heated seat pads do not state what current each circuit requires. All I know for sure is that they are fitted with a 20A fuse, so it is safe to assume each seat uses no more than 10A. I've used that to size all the wire gauges.



I'm using an extended fuse box cover. I bought it so I had enough space for the extra relays without struggling but it was also the ideal place to mount the heated seat switches.


I made a bracket to mount the relays under the existing fuses.




Measuring where to cut the rubber mat

Before fitting the new Exmoor Trim seats I fitted the under seat rubber mat. Another Exmoor Trim product.


I've used some 1/2" (12.7mm) spacers to stop the seat rails catching on the thick rubber mats. The mats are so thick, I've found, that it needs at least 12mm spacers for the seat to move freely.




I needed longer seat bolts, so I bought some stainless steel M8x40mm torx pan head bolts which do the job nicely. I've done the same in both Defenders.






With the mats and the seats in, I threaded the cables before fitting the carpet and cubby box.



I've used Discovery 2 (D2) heated seat switches because, at the time I was looking, I could not get Defender TD5 or TDCi switches. The D2 switches are the same as the Defender switches, they just have different style caps. I've wired them so that the tell-tale lamps and the backlights work.





Tested and working well. Nice and warm.

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