Dodgy R25 speedo

When you say "flashing" - do you mean a regular, rhythmical flash, or sort of a "flicker" - inconsistent in timing?

IMO, if its a regular flashing display, you have a sensor fault. If it's an irregular flicker, you've got dry joints or connection problems.
 
Yeah sorry, I never really described the way it "flashes" very well... The flashing is consistent and regular - like a digital clock. It's not randomly flickering as though there's a loose connection or something. Sensor fault then? I'll start checking out the fuel sender and wiring (and connectors) tomorrow.

And now some really bad news. I went over to Ringwood Speedos today to get some info on servicing the speedo, and it turns out they don't want to touch the things any more! :eek: The guy I spoke to said they'd had too many bad experiences with R25 cluster repairs that didn't last, and with owners who blamed them for making things worse after other parts of the cluster stopped working after a repair. He said they just can't source new parts for them anymore and while they could probably use 2ndhand bits, it wasn't worth their time and effort when something else goes wrong shortly afterwards.

He couldn't recommend anyone else to do the work but suggested that I just try ringing around. Time to get out the Yellowpages...

Can anyone recommend any other speedo specialists who have had more luck with these speedos? Has anyone actually tried calling up Renault to source a new speedo unit? I might give it a go when I've got time.

Cheers,
Richard
 
Thanks for the link. I'll shoot off an e-mail to them soon. :cheers:

$2000 for a new speedo is a joke. Is the soldering any better on them I wonder? Probably not. :mad: :whip:
 
silverexec said:
$2000 for a new speedo is a joke. Is the soldering any better on them I wonder? Probably not. :mad: :whip:
Click to expand...

The problem is inherent to a flexible circuit which has soldered connections. vibration will eventually cause another fault. I doubt that the "new" part differs in any way from the original, I'm told by Renault that the replacement transmission shift computer (which renault wants $1900 for) has the same circuit as it did 30 years ago- which means no spike or surge protection, dodgy connections and dodgy soldering- all on one of those circuit boards where the tracks come off if anything is resoldered :mallet: :mallet:

Europa, what sort of $$ did a rebuilt trans computer cost you (from the link)?

Farmerdave
 
Now I'm really annoyed about being sniped by some bastard on Ebay for a brand new R25 speedo that went for 14 quid :mad:

Last time I spoke to Ringwood speedos they were very helpful and seemed quite confident of a good result. How irritating...

What about modifing some thing common (say a jap electronic speedo) to work with the reno sensor and sit it behind the reno face? Might be worth asking the speedo shop if it doable?
 
Haakon said:
Now I'm really annoyed about being sniped by some bastard on Ebay for a brand new R25 speedo that went for 14 quid :mad:
Click to expand...

Only problem would be that it is all in MPH, apart from the microscopic sized Km/h markings, as well as miles odometer that may/may not be calibrated to a different pulse from the sender........
 
Simon said:
Only problem would be that it is all in MPH, apart from the microscopic sized Km/h markings, as well as miles odometer that may/may not be calibrated to a different pulse from the sender........
Click to expand...

For that price I was willing to live with a MPH odometer - the face would have been swapped for my KMH one. I reckon the odometer could have been swapped easily too - it was the actual bits that made the needle move was what I was really after!! deep sigh.... :rolleyes:

s/h ones seem to pop up on Ebay UK occasionally, but they are usually as part of the whole instrument assembly which equals killer postage.
 
Just a brief update - I was able to fix the fuel gauge :headbang:. Problem turned out to be that I'd accidently disconnected the 12V supply to the small "computer" in the boot that the fuel sender connects to. I'd disconnected it when I was fiddling around with the interior boot light that doesn't work, and I'd stuffed up the wiring when putting everything back together. :mad: :mallet:

So after sorting out the wiring and putting everything back the way it was, the fuel gauge works again! Many thanks to farmerdave for his help. :cheers:

The speedo still doesn't work though, so I've taken the cluster to Howard Instruments in Heidelberg Heights for them to sort out. The guy sighed when I mentioned "R25" :rolleyes:, but they're going to take a look and let me know what they think of it. A working speedo would be really nice...

Richard
 
This really is becoming painful. :mad: Where's the mental breakdown smilie?? :cry: Howard Instruments were able to fix the speedo and make it run on their bench - problem turned out to be a stuffed IC. I put the speedo back in the car and surprise surprise, it didn't work.

I think "OK, problem must be the speedo sensor on the tranny" so I head out to Caravelle and pick one up (Ken had them in stock - I was very impressed :D ). I spent all evening getting the thing installed and plugged everything together, and guess what, IT STILL DOESN'T WORK!!!

:mallet: Maybe I should just get a GPS unit and strap it to the dash because I'm absolutely fed up with this crap.

The only thing I can think of that might be the problem is the way the sensor sits in the transmission. On the sensor, there's a circular channel cut out about 5mm from the end where the cable exits. I've only been able to get the sensor in to the transmission as far as this cut out. I don't know if it's supposed to go in any further but it seemed like that's as far as it would go. Also, is it supposed to twist and lock in place, or just push in as I've done? Any help would be much appreciated.

If all else fails, I'll be bringing the whole car along to Howard Instruments to sort out, I really can't be stuffed anymore.

Cheers,
Richard
 
Well, I haven't been around for a while because of work and being too tired to dial in to the net in the evenings, but I've made an effort because I had to share the good news - THE SPEEDO WORKS!

:dance: :cheers: :banana: :banana: :banana: :banana: :cheers: :dance:​

Finally figured the damn thing out, it turned out to be a dry joint of course. :mad: Here's the story...

I was able to get hold of a portable oscilloscope and found that I WAS getting a signal from the sender cable when the car was driving, so the problem had to be in the actual speedo. Totally out of ideas, I was checking the continuity of the tracks between parts of the PCB and each connector, and found that the GND terminal where the sender cable plugged in had no continuity to the 8-pin connector on the rear of speedo (which supplies the speedo with voltage and ground from the instrument cluster PCB).

After checking various tracks on the PCB, I found that the GND track on the bottom layer of the board connects to the GND track on the top layer via the leg of a diode soldered on both sides of the board. When I tested the solder connection on both sides of the board, it turned out to be open circuit. Getting excited, I resoldered the diode on both sides of the board and checked the continuity again and found that the GNDs were now connected which gave speedo sender its earth connection back. I took the car around the block and the speedo had burst into life! :dance:

Damn dodgy soldering! It caused me months and months of unnecessary grief but at least it now works, for a while anyway...

Hooray! Hooray! :adrink: :banana: :banana: These banana things are great aren't they! :banana: :banana:

Cheers,
Richard
 
I'll swap you some continuity testing/soldering on my instrument panel for installing and tensioning your cambelt? :D
 
Hmmm, you serious?? That's a very tempting offer. :deal: My only worry is that I don't know how long it would take for me to check out and that something else might stop working... :doh: Will you be needing your car anytime soon?? :D

Would it be just to check out your fuel gauge issue or are there other gremlins lurking around?
 
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