V8S and 290S speedometer

V8S and 290S speedometer

Author
Discussion

rupertrr

Original Poster:

39 posts

90 months

Saturday 16th March
quotequote all
Good afternoon.

I have a 1992 V8S and the speedometer has packed in. Neither the speed nor the distance are working.

I have enquired about getting it mended but was told that parts are no longer available and it will not be possible to sort it out.

Can anyone here please advise if the speedometer from a S3 290 will work in the V8S. Obviously the gearboxes of the two cars are totally different but the speedometers look the same and the wiring plug into the back of the unit etc appear identical. I am thinking that maybe the pulse from the gearbox sender thingies will be different, so that even if it works in the V8S the indicated speed will be totally wrong.

Can anyone help, please?

As an alternative, has anyone tried using a GPS speedometer in their car. It would be totally independent of the gearbox sender and might be an alternative worth trying if I can't get my original one sorted.

Many thanks to you.

v8s4me

7,242 posts

219 months

Saturday 16th March
quotequote all
Are you sure it's the speedo and not the sender unit? Either way call Speedy Cables. If they are still in business they can fix both units. One thing they aren't though is "speedy" smile

In the meantime I don't think the V6 tacho will help you. The V8S sender runs off the Rover LT77 gearbox whereas the V6 unit, assuming it runs off the Ford 'box, won't be compatible with a V8S speedo.

If the sender unit has failed you might also experience cutting out problems as you come to a stop at eg traffic lights. This is because the ECU also gets a signal from the sender unit.



Edited by v8s4me on Sunday 17th March 13:27

GreenV8S

30,206 posts

284 months

Saturday 16th March
quotequote all
rupertrr said:
I have enquired about getting it mended
Who did you ask? Speedy Cables as mentioned above used to be the go-to company for fixing speedos but I'm sure there will be others.

If it's only the sender at fault, that may be4 even easier - it's not as if TVR made the own senders.

Also check for a simple wiring fault.

If the gauge has failed and is beyond economic repair then people here have reported buying compatible electronicreplacements. You may not end up with an exact matching gauge face unless you put more work into it, but it's up to you how much effort and money you want to put into this.

v8s4me

7,242 posts

219 months

Saturday 16th March
quotequote all
GreenV8S said:
......Also check for a simple wiring fault..........
A definite possibility given the way the cable from the gearbox is routed. Several sharp edges to rub against.

hillclimbmanic

612 posts

144 months

Saturday 16th March
quotequote all
rupertrr said:
Good afternoon.

I have a 1992 V8S and the speedometer has packed in. Neither the speed nor the distance are working.

I have enquired about getting it mended but was told that parts are no longer available and it will not be possible to sort it out.

Can anyone here please advise if the speedometer from a S3 290 will work in the V8S. Obviously the gearboxes of the two cars are totally different but the speedometers look the same and the wiring plug into the back of the unit etc appear identical. I am thinking that maybe the pulse from the gearbox sender thingies will be different, so that even if it works in the V8S the indicated speed will be totally wrong.

Can anyone help, please?

As an alternative, has anyone tried using a GPS speedometer in their car. It would be totally independent of the gearbox sender and might be an alternative worth trying if I can't get my original one sorted.

Many thanks to you.
Speedy Cables aren't very quick or helpful! I've just taken my pre-cat Griff speedo to Ryan Linley Restorations, in Swansea area. He used to be the technical director of Speedy Cables, and is much cheaper and quicker AND cleverer!!

v8s4me

7,242 posts

219 months

Saturday 16th March
quotequote all
GreenV8S said:
......Also check for a simple wiring fault..........
A definite possibility given the way the cable from the gearbox is routed. Several sharp edges to rub against.

mentall

453 posts

130 months

Sunday 17th March
quotequote all
As to using gps: YES!

I used my last-but-one smartphone (velcro'd to the dash) for months, using the (free) GPS Test app as a full- screen speedo. Instant km/hrs switch, and it only let me down in tunnels!

I was waiting for (the otherwise excellent) Speedy Cables, of course.

Edited by mentall on Sunday 17th March 07:01

rupertrr

Original Poster:

39 posts

90 months

Sunday 17th March
quotequote all
Hello - OP here again.

Many thanks for all the helpful suggestions that everyone has made.

The speedometer that I have fitted was originally recording speed perfectly well but the odometer bit wasn't working. It was stuck on ----99.9 miles I tried tapping it as I drove along, as suggested in other threads, but it didn't make the odometer work so I took the speedometer out and had a look inside - then decided it was beyond my abilities to fiddle with it so I contacted Cluster Repairs in Waltham Abbey (who are not that far away from me) and they advised a lack of spare parts to repair the odometer. They were very helpful (I have used them before to replace the failing LED readout on my early Range Rover L322. They did a perfect job of it and their repair has lasted much longer than the original that Land Rover/BMW did) so I tried them for my TVR speedometer but to no avail.

I put the speedometer back in the car deciding that I could live without knowing the mileage as long as I knew the speed only to find the speedometer side of things didn't work either. I assume I messed something up when I had a look inside.

I was experiencing the engine cutting out when I came to a halt although it would start again immediately but I have fitted a new ignition amplifier and a new coolant temperature sender (the ECU one rather than the temperature gauge one) and that problem has now been resolved I am pleased to say.

I think my course of action for now will be to take it out again and recheck the connections and earth. If that doesn't work I will have a look underneath to see if the speed sender cable is OK. I may be able to borrow a speedometer out of a 290S (which is what prompted my original question) so may try that as a last resort just to eliminate everything else. Failing all that it sounds like a call to Speedy Cables and apparently a long wait, or more likely to Ryan Linley Restorations, although I am still considering the GPS idea.

Thank you everyone. An excellent example of Pistonheads at its best.

Edited to add a bit more waffle.



Edited by rupertrr on Sunday 17th March 09:03


Edited by rupertrr on Sunday 17th March 09:37

v8s4me

7,242 posts

219 months

Sunday 17th March
quotequote all
said:
.............. so I took the speedometer out and had a look inside ................
Not a great idea smile

said:
.............. I assume I messed something up when I had a look inside............
Possibly.

said:
.............I was experiencing the engine cutting out when I came to a halt although it would start again immediately ........
This indicates a faulty sender and/or wiring.

Based on personal experience I'd suggest getting under the car and unwrapping the full length of the wiring from the sender to the speedo. The cable is routed over the gearbox and rubs against the edges of the casting. But there could be a break anywhere. This was one of my wires...



My sender was faulty as well. This was a Speedy Cables job.

So I suggest you re-check the wiring to the back of the speedo and refit it. Then check the wiring from the sender to the speedo. If it still doesn't work then use a GPS unit for the summer and send the sender and speedo off to SC in the autumn.

You could also try JDO Instruments but read the FAQ about what they will and won't fix carefully. They get very tetchy if you ask for a service the FAQ say they don't do biglaugh


mentall

453 posts

130 months

Sunday 17th March
quotequote all
My speedo had been hacked open by a previous owner. It worked when I bought the car, but not for long.
Speedy needed the sender as well, to calibrate the unit. I had to buy a cheap sender on eBay to plug the hole in the gearbox, while I used the GPS.
Speedy's service was excellent (but so s-l-o-w!). Do be aware that they fit a digital mileometer: looks OK but not original.

rupertrr

Original Poster:

39 posts

90 months

Sunday 17th March
quotequote all
Thank you to V8s4me and Mentall for the latest posts.

I've got the dash board and instruments out this afternoon and checked the wiring at the speedo end and all appears OK. I'm going to get the car up on ramps during the week and have a look at the wiring down below. I'll keep the dash off until I've checked everything.

Wish me luck.

Thank you again, everyone.

Fefeu52

198 posts

66 months

Monday 18th March
quotequote all
I agree with Mental and V8S4me, look at the transmitter and the wiring. You could maybe plug the speedo, the transmitter and a 12V-battery on the workbench, there is not a lot of wire, and moving the transmitter with a drill, you could check the 2 devices.

rupertrr

Original Poster:

39 posts

90 months

Monday 18th March
quotequote all
Thank you, Fefeu52 - that's a cracking idea. I'll give it a go once I've traced back to it.


hillclimbmanic

612 posts

144 months

Saturday 30th March
quotequote all
I'm guessing that the gearbox is an LT77? There are 2 different senders(Transducers), a 4 pole, and an 8 pole. They cost about £170+VAT. Again, I'm guessing that the speedo is a Stewart and Warner (S&W)?

Speedy Cables convert your speedo to digital for about £600 eek

Ryan Linley Restoration WAS the Technical Director for Speedy Cables, and is the guy on the SOS car show, and Top Gear You Tube videos, explaining things!

https://ryanlinleyrestoration.co.uk

Contact details are on his website. He is MUCH quicker AND cheaper than Speedy Cables, and very helpful; he is fixing my Griff Speedo(S&W), at the moment...

Manic



Edited by hillclimbmanic on Saturday 30th March 11:53

rupertrr

Original Poster:

39 posts

90 months

Sunday 31st March
quotequote all
Hello - OP here again.

Thank you to hillclimbmanic (above post) - yes it is the LT77 gearbox. Good info on the different senders. Thank you.

So far I have been underneath my car and found the sender unit in the gearbox. I have traced the wiring from it and that all seems fine. There is no point at which it has been trapped of chafed on anything that I can see, even with an inspection mirror and one of those little camera things that you can poke down holes to look inside engines. Without taking the exhaust off I can't reach the sender unit to remove it and I haven't had time to do so yet.

However - I have got hold of a speedo from a 290S and tried it on my car. It works, showing speed and the miles are clocking over. Unfortunately though it is wildly inaccurate, the speed reads a lot higher than reality (checked against my sat-nav) and the miles are clocking up at about twice the true distance. I am assuming from this that the sender is sending a signal and that it is the different gearing of the V8S and 290S that is making the difference. I am more than happy to be corrected on this.

I have emailed Ryan Linley about my V8S speedo and getting it looked at but have not heard back from him yet. In the meantime I am leaving the 290S speedo in my car - to fill the hole up in the dashboard as much as anything - and have ordered a cheap GPS speedo to use until I can get the original speedo fixed.

Thank you again, everyone.

v8s4me

7,242 posts

219 months

Tuesday 2nd April
quotequote all
rupertrr said:
............... I am assuming from this that the sender unit is sending a signal and that it is the different gearing of the V8S and 290S that is making the difference. I am more than happy to be corrected on this. ......
It's how the signal from the sender is being read by the speedo which is making the difference. If the V6 speedo is reading double then it's possible you have an 8-pulse sender and the V6 uses a 4-pulse sender. You'll need to get the sender unit out the see which one you have.

On the up-side, it sounds like you have a working sender unit.