Jump to content

Recommended Posts

I'm guessing the handbrake switch is an earth switch?

If so, it shouldn't be too hard to re-black the ABS logo and etch the paint with 'PARK' or similar.

Depending on how steady your hand is of course!

in the Td5 warning light wiring, the glowplug wire is Black/yellow trace NOT Yellow/black trace,

I'm going off the original vehicle wiring, yellow/black as the feed into and out of the original warning bulb.

So far the only TD5 wiring is the instrument harness, which is untouched and OE spec.

Now I've had a proper think there must be a problem with the original relay or relay wiring, rather than the warning lamp wiring.

2 wires to the original warning bulb. Since one is an ignition feed, the other should be an earth to light the bulb.

As it is I have an ignition feed and a relay output feed.

Think you might be right about the main relay earth, I would get exactly the symptoms above if the relay is earthing through the output switched earth and not a dedicated chassis earth.

Link to post
Share on other sites
  • 3 weeks later...

Eventually got my temp gauge to work :D :D :D

Checked everything - wiring mod 5 times, new sender, flushed system even boiled kettle on wing and dumped sender in. That showed the wiring mod, gauge and sender were working correctly so came to the conclusion that there must be an air lock somewhere (possibly introduced when I changed the sender and put a new thermostat in). Despite following the rave instructions, making sure the heater circuit was full it still wouldn't work. :angry2:

Then I remembered reading somewhere that you have to get the front higher so parked it the other way round on my drive (which slopes slightly) . This morning took the stat plug out and found an airspace there and in the rad so filed it up went for a run and it works. Just to make sure, I've got the engine nice and hot so the stat was definitely open and parked it facing up hill again.

Malcolm

Link to post
Share on other sites
  • 5 months later...

Sorry if this has been answered already, I did a search and trawled through the thread but only found a part answer.

Has anyone made a circuit to make the alarm led in the middle of the speedo blink when the ignition is switched off?

Like most cars that have the speedo conversion, mine doesn't actually have the alarm but any small deterrent has got to be better than nothing. (I also use a steering wheel bar)

Malcolm

Link to post
Share on other sites
Sorry if this has been answered already, I did a search and trawled through the thread but only found a part answer.

Has anyone made a circuit to make the alarm led in the middle of the speedo blink when the ignition is switched off?

Like most cars that have the speedo conversion, mine doesn't actually have the alarm but any small deterrent has got to be better than nothing. (I also use a steering wheel bar)

Malcolm

Diesel jim who used to be here did & sent me the info, I'll find it & post in here shortly, But I couldn't make it work.

post-20-0-44488700-1367439498_thumb.jpg

post-20-0-78515000-1367439504_thumb.jpg

Link to post
Share on other sites

From Westerns attachments, I think I can see how the relay will send power to the led when the ignition is off so that's one thing to make up and try.

I guess what I need now is a circuit that's fed by that relay that flashes the led rather than light it permanently.

It would make a nice little addition to the Td5 dash if it can be made to work.

Thanks so far

Malcolm

Link to post
Share on other sites

one of these might work.

the one I got from DJ is the first 4 attachments, I couldn't get it to play the game, so went for the one in the last 2 attachments. but it doesn't drive the speedo alarm red led, only a seperately fitted item.

post-20-0-53679900-1367516167_thumb.jpg

post-20-0-37644600-1367516171_thumb.jpg

post-20-0-15468100-1367516175_thumb.jpg

post-20-0-66323900-1367516182_thumb.jpg

post-20-0-13623100-1367516233_thumb.jpg

post-20-0-61630300-1367516242_thumb.jpg

Link to post
Share on other sites

Great, found a 555 astable timer, now need to find the relay. There seem to be loads of them that look the same to someone who doesn't fully understand them. I realise I want one as in Western's diagram, that when the ignition power is off it connects 30 to 87a. Do all relays with those numbers do that?

I can already get that distinctive smell when I'm soldering - burnt flesh! :blush:

Malcolm

Link to post
Share on other sites

I'd expect that a standalone fake alarm thing like that would work by pulsing the LED with a positive voltage (+12V for example), however I believe the LED on the Td5 speedo head requires a connection to ground to light. In other words it's powered from the other side.

You'd have to use that circuit to switch the LED to ground in pulses to give you the flashing effect.

Link to post
Share on other sites

OK, I'm going to get a relay to switch it on using the ignition as per Western's plus a 555 astable timer and should then have a flashing led that I can put in a spare place on the dash/console.

To get the led in the speedo to flash it seems I need to switch the earth on and off and I thought maybe I could use the output from the timer to switch an earth on and off.

Being more mechanically minded, can I not use another relay with the timer output energising the coil and the speedo led earth being on contacts 30 and 87a?

From physics lessons many years ago ( i learnt about valves) I remember being told the new fangled things called transistors are just electric switches so could I not use one of them instead? Or do they only switch voltages?

Hours of fun and frustration to come.

Sit back and wait for why it won't work - won't be offended, just trying to learn.

Malcolm

Link to post
Share on other sites

If the resistor is swapped out for a variable one then you could adjust the speed. Probably choose one double the size of the fixed resistor that is there.

I'm just doing a few final checks to see if it would be better to have a transistor to switch the led rather than the gate output. I was going for cheap and cheerful, current component cost would be less than a quid (although they were just bits I had laying around).

Link to post
Share on other sites

Revised diagram to add a transistor so we keep within the current spec of the chip. Tested and works as per previous design other than we now only have approx 1ma drain in the chip output as opposed to the previous 12ma drain.

post-25689-0-30547200-1367619469_thumb.jpg

The chip has a max supply rating of 18 volts, does anyone know if we would expect to exceed that on the cars power?

If so we might want to add a voltage regulator.

Components used

IC1 = CD4001UBE (This must be a CMOS version other types have too low a max voltage)

R1 = 2.7 M ohm resistor

C1 = 150nF capacitor

R2 = 10K ohm resistor

D1 = 1N4007 diode

Transistor = BC547

Increase R1 to slow down flash rate

Link to post
Share on other sites
Blimey, I've not had time to build the 555 timer yet and you've already got something from scratch working!

Also without using a relay it's a lot neater.

Impressed !

Malcolm

In fairness Malcolm building it up on a breadboard like I did is pretty quick for testing purposes, I also happened to have all the components laying around (once I found them!).

One of these days I really should get around to actually installing the speedo in my 110! So you are all miles ahead of me on that front! :)

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy