Jump to content

TD5 Speedo Mileage run up circuit


Recommended Posts

I used the red led in my last 90's speedo as the warning light for the winch power supply on via a relay :)

Mo

You got me thinking Mo. I could use it to indicate when my electric fans are switched off, that's to say when the thermo switch has been overriden.

Link to comment
Share on other sites

You got me thinking Mo. I could use it to indicate when my electric fans are switched off, that's to say when the thermo switch has been overriden.

So out of curiosity then as I have only looked at the normal speedo functions what else does this gauge do?

Link to comment
Share on other sites

You got me thinking Mo. I could use it to indicate when my electric fans are switched off, that's to say when the thermo switch has been overriden.

Good idea! I was going to fit an LED for this purpose, and there's one in my dash already :P

So out of curiosity then as I have only looked at the normal speedo functions what else does this gauge do?

As well as telling the speed the speedo head:

  • Damps fuel gauge, provides low fuel signal to warning light pack LED when approximately 2 gallons remain in tank.
  • Trims temperature gauge signal, for ROW-spec models with 300Tdi engine, by way of an in-line resistance.
  • Provides a modified (I think it halves the frequency) speed sensor signal to the ECU.
  • Provides an LED (driven by alarm ECU) to indicate alarm/immobiliser status.

Link to comment
Share on other sites

So is the low fuel light on the speedo? or just gets switched through the speedo?

low fuel light is in the warning light panel, top row see picture below [all the hand written notes are mine]

red led has to be earthed to light it up, would need a NOT gate thingy to make it flash.

Question ---

What does ABS mean [note my 110 does NOT have ABS fitted, so it's nothing to do with ABS system] there is a clue on the picture :P

post-20-0-61617300-1309295310_thumb.jpg

Link to comment
Share on other sites

Cheers Ralph, I'd not seen a TD5 warning panel. I'll be tempting myself into a conversion at this rate! :)

go for it, easy to do now with James's website conversion info & all the info in the wibbly wobbly speedo thread in this forum

got the answer to my question yet ?????

Link to comment
Share on other sites

on the right track, but not quite,

1st word = what do you use to apply the park brake lever ?

2nd word is brake :D

3rd word -= what we are if the transmission brake is left on & then try to drive away ? begins with S

' _ _ _ brake _ _ _ _ _ _

Link to comment
Share on other sites

As long as what they're selling is what they've got a photo of, rather than what they've described, then yes. I'd say so :)

I spoke to them this morning and it has been confirmed to me as a TD5 speedometer :)

They also said they would be willing to post it! :D

That'll save a 100 mile round trip :D :D

Link to comment
Share on other sites

Good idea! I was going to fit an LED for this purpose, and there's one in my dash already :P

As well as telling the speed the speedo head:

  • Damps fuel gauge, provides low fuel signal to warning light pack LED when approximately 2 gallons remain in tank.
  • Trims temperature gauge signal, for ROW-spec models with 300Tdi engine, by way of an in-line resistance.
  • Provides a modified (I think it halves the frequency) speed sensor signal to the ECU.
  • Provides an LED (driven by alarm ECU) to indicate alarm/immobiliser status.

out of curiosity retro where did you come by this info (in no way questioning it) as i would like to dig a bit deeper into the design of the speedo for another project i have?

Link to comment
Share on other sites

Somehow completely missed this thread, love this sort of thing. Have you got anywhere with the mysterious 8000 value yet? Does changing it make any difference? If you were saying that that stops the speedo moving and subtracts amount from the miles, maybe that's how you "down clock" it?

Link to comment
Share on other sites

out of curiosity retro where did you come by this info (in no way questioning it) as i would like to dig a bit deeper into the design of the speedo for another project i have?

Just info I have gained over the past year or so of fiddling with them, most of it gained through this forum and the RAVE manual.

Somehow completely missed this thread, love this sort of thing. Have you got anywhere with the mysterious 8000 value yet? Does changing it make any difference? If you were saying that that stops the speedo moving and subtracts amount from the miles, maybe that's how you "down clock" it?

To down-clock you just set the counter value to whatever value you want I believe :)

Link to comment
Share on other sites

Somehow completely missed this thread, love this sort of thing. Have you got anywhere with the mysterious 8000 value yet? Does changing it make any difference? If you were saying that that stops the speedo moving and subtracts amount from the miles, maybe that's how you "down clock" it?

Taking miles off is done just by changing the first 16 bytes in memory using the calculation MrKev worked out on page three of this thread. http://forums.lr4x4.com/index.php?showtopic=69070&view=findpost&p=591401

The mysterious 8000 value is still mysterious, to be honest a lot of the values if changed stop the needle moving. This is probably because it is crashing the code running on the microcontroller because the values are incorrect, knowing which values are valid will be a challenge.

Currently I am using a Speedo kindly loaned to me by Retroanaconda so I am treading lightly, I'll be swapping this out for his other speedo this evening which will give us another example of memory contents, as they are similar speedos anything that differs between them must have something to do with storing the mileage or a serial number of some sort.

Also there is a KPH speedo coming our way soon and it is hoped examining this will reveal if it is possible to convert between the two types and if it is possible to recalibrate these in an arbitary fashion... or it may just reveal how easy it is to part me from my money! :P

Link to comment
Share on other sites

on a slightly different topic but related to the speedo. im working on a project to make high quality replacement dial faces for my gauges. if i can get them to a high enough standard and functionality i will post this in the tech archive for those that are interested. I don't want to prize open my TD5 speedo to find that i cant get the standard i want in the end.

would it be possible for any of you guys to take a scan of your dial face and e-mail it to me while you have it off? it would be very appreciated

Link to comment
Share on other sites

I have only just this lunch time finished recrimping this one back together :( James is going to do some testing before we open the next one but I'll take some hi res pics if you like when I do. The face is quite thick and has some sort of prismatic property to help with illumination

Link to comment
Share on other sites

I have only just this lunch time finished recrimping this one back together :( James is going to do some testing before we open the next one but I'll take some hi res pics if you like when I do. The face is quite thick and has some sort of prismatic property to help with illumination

any effort would be appreciated but i suspect only a scan would do the job, whats the best method for opening and re crimping/

Link to comment
Share on other sites

Finally I have the correct mileage in my car :lol:

post-10578-0-28885900-1309378745_thumb.jpg

Took the long way home and put 12.5 miles on it, everything behaved as normal and the miles clocked up as I expected. So all is good in that respect. Hopefully tomorrow morning the trip mileage will still be there, but I don't have any reason to believe it won't be. During testing it has remembered a distance.

Spot on ^_^

Link to comment
Share on other sites

any effort would be appreciated but i suspect only a scan would do the job, whats the best method for opening and re crimping/

I'll see what I can do when I open the next one, depends on how the needle is held on as to whether a scan is feasible as I imagine the face will need to be flat against the scanner plate.

To open the speedo up I use a mobile phone opening tool which is basically a bent tipped screwdriver and slowly work my way around a couple of times easing the crimped edge up. Don't prise it up too far, just enough so you can push it off with your thumbs.

When it comes to putting it back together ease the metal part back on then place the face of the speedo flat down on some clean mdf that has a hole drilled in it for the reset button to sit in, then place a small amount of pressure on the back of the speedo with a clamp of some description (this compresses the foam in the metal ring) and then using a lump of hard plastic and a small hammer gently tap the edge you raised earlier back into place.... work around in a circle a couple of times till you are happy. The end result is pretty tidy apart from some lost paint that won't be seen.

I'll post some pictures of what I mean when I open the next one up which should be in the next day or two.

Link to comment
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