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TVR Tasmin, Dirty Wires and Bright Lights

Not one to let a nasty cold get in the way of progress, I did some more work on the TVR today.

The first course of action for the day was to see how the car starts. After a couple of splutters and a bit of cranking (much less than yesterday), it fired into life. Not perfect, but better.

I couldn’t help myself and had to take it for a quick run down the road and back. This uncovered a couple of things. One, the steering wheel is WAY off centre (which I didn’t know whilst trying to back up my driveway), and the brakes pulsate a lot. Hopefully, an alignment will sort the steering issue, and some hard braking might clear the brakes as I suspect they are covered in rust/dirt.

On the plus side, it did go down the road in one piece. I didn’t get out of first gear (very short road), but the clutch seems to work well. Its too wet outside to go further, with no wiper, and a very un-weatherproof roof.

When I returned from my maiden voyage I wanted to have a look at the plugs. I only removed one, but that was enough for me.

They don’t look that old, but very black. Not wet which is good. According to my records, they are the wrong heat range and should be BPR5ES

I’ll grab some new plugs and swap them out. Hopefully, that sorts some of the niggles when starting and running.

Not to be deterred, I pushed on with some other little jobs. First was to upgrade the radio to work with my phone, and crank some Spotify. It was a quick and easy upgrade.

Aww yeah, A cassette adaptor I had kicking around for years (see, hoarding works!). Actually works surprisingly well and doesn’t sound terrible. All speakers work, and the flash EQ works a treat

This can stay for a bit. Does what I need it to do, although I need to work out how to get the antenna up so I can get FM stations too. It’s not like I really need music though, the engine is music enough.

With that success, I moved onto the next thing on my list. The dodgy headlight switch. Two things bothered me about it. First, the wiring was dodgy enough to need wiggling to work, and second, the switch was upside down. The icon was on the bottom, and the switch was up for off and down for on.

The switch pulls out the front once the connector is removed, but there is also a white plastic sleeve that pushes off. The sleeve is to illuminate the icon via fibre optic cable, but mine isn’t currently working.

The reason for the wiring being a bit dodgy was that the connector has obviously suffered some high resistance and the plug housing is damaged, allowing the terminal to float freely

I pushed it firmly into the connector on refitting, but I may need to close the terminal a bit to make it a tighter fit. I also need to look into using some relays to re-wire the headlights directly and take the load off the switch.

The switch its self had some minor corrosion on the terminals, but nothing a quick scrape with the screwdriver couldn’t sort

And refitted the correct way around. Down for off, up for pop-ups UP.

The next thing that bugged me was the interior light switch… which seemed to be missing everything but the surround. The interior lights didn’t work.

I removed the surround and found the guts of the exploded switch had been pushed down into the center console. I carefully fished the switch block and connector out. The rest of the springs etc are stuck down there and can stay there until the console has to be removed

You can see a good example of the black wiring in this car. Each wire is black, but does have a coloured collar at each end to identify it. Its not actually that bad to work with, but coloured wires are still preferred.

Using the handy diagram I checked which terminals did what on the switch

Obviously the two bottom ones are a joint +12, and the two other terminals are either “door open” or “on” settings (grounds to turn light on). I tried bridging them with wire and got nothing from the lights. I popped one of the lights out to check the bulb (there was one, it’s removed in photo)

The bulb looked good, so out comes the multimeter. No power at the light when the switch terminals are bridged. No power at the switch +12 terminals. Hmmm.

Ok, what’s upstream of the switch? The fuse. I had checked the fuses visually yesterday and they all look good, but something was obviously up. Interestingly I note that fuse 6, which powers the interior lights, also powers the hazard lights, which also are not working.


This is the fuse and relay box. Lovely.

Fuse 6 is the red one about halfway down. It wasn’t blown, and the multimeter said I had power on each side of the fuse. The power comes into the fuse on the RH side of the photo and out on the LH side, through the fuse. I disconnected the wiring, removed the fuse, and cleaned everything up. There was some corrosion in the terminal, and everything is very dirty.

The result was this

Hazard lights! A handy thing to have on a British car.

Which also means, I now have power to the interior light switch.

I popped an LED bulb into the holder, and bridged the terminal

Ooooooh, light.

Only one was working, so I jumped onto the passengers’ side, popped the light out, and found that the wire hanging under the dash was from that light.

I popped another LED bulb in that one, reconnected it and BAM, let there be light!

Because the switch was buggered, and there was no point in finding another. It only operates these two “knee” lights, so when am I ever going to need to set them to “on”, and they are LED so no point in turning them “off” when they turn off when the doors are shut anyway.

I decided to bridge the terminals and leave it. I made up a jumper, using a pair of specially modified (squished in a vice until they fit) bullet terminals and some wire.

To make it pretty, durable, and safe, I wrapped the lot in tape and then stuffed it into the center console

TVR-Parts still sell the switch blanks, so I’ll grab one of those and replace the interior light hole with one of those

Unfortunately it wasn’t all quite straight forward. The door switches weren’t quite playing ball. The passengers side wasn’t hitting the pad on the door correctly so wouldn’t trigger the lights to turn off when shut, and it turns out the drivers side one had been unplugged. I swapped that over, so the passengers side is unplugged, and the drivers is now plugged in and working correctly.

So, I now have sweet interior lights, and working hazard lights. Isn’t it inviting?

Love the warm white LEDs. Much better than the usual cold white, or incandescent bulbs. Also puts a lot less strain on the wiring and battery.

Its small things, but in the world of British cars, it’s a big victory to have things working.

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