speedo

[Jimmy5]

Hi guys

Have an intermitent problem with the speedo, basically it packs up for abit then if car hits a pothole etc it will come back on, so looks like a dodgy connection. Problem I have is where does it connect into the gearbox? Plus could this be a case of just tightening up a loose bolt? One thing i have noticed when speedo is working is that is about 4-5mph out so when im doing 30 am actually doing 35 (is there anyway to correct this?)

Cheers

James

[adscan]

mine does the same. if i tap the speedo it comes back into life. are you sure it is not a dodgy connection behind the dash where it connects to the clocks?

i keep meaning to take my clocks out to take a look.

[Jimmy5]

Havent checked behind the dash yet, but have tried tapping the speedo which does nothing, only a pothole gets it going again! Makes me think its the connection with the gearbox

[rat1]

mine was the same, turned out to be a connection at the back of speedo. as for the speedo reading to low,if you carefully pull the needle off and then lightly put it back on above where you won't it then turn it down to the correct position then push it on fully :)

[Thundercat]

Hi james, check first at left hand side strut top where air filter bracket is, there should be a round black plug and socket. Usually find by pulling it apart and spraying with some wd40 then pluging and unpluging a few times that it cleans pins up. Secondly behind the dash clocks you have a plug on lhs with three wires on it, unplug it and a light rub with some scotch bright on copper circuit board normally removes the dull contacts.
Sensor at gearbox is the last thing to play with but a pig to get to, if it needs attention then then pop your car round and i'll remove a clean it.

[Jimmy5]

Cheers Jon, Rat1 will have a gander tomorrow night (if the weathers good):agree:

[Jimmy_GTT]

Here we have the same problem with 2 cars that the speedo shows 4-5mph less.
Needle hasn't been touched. I'm afraid it is something about the speedo clock.
(I had a similar problem about 10 years ago with my previous GTT and a clock change has solved the problem)

[adscan]

did this get sorted? i am interested as mine is doing the same.....:(

[Jimmy5]

sorted intermitent problem out - that was the connection at the back of the clock.

As for mph being wrong, I tried adjusting the needle but its just made matters worse and its 10mph out now :confused:

[Woznaldo]

You can adjust the speed by taking the speedo out of the instrument pack and adjusting the Variable Potentiometer with a small instrument flathead screwdriver. It's an annoying job as you have to keep pulling the speedo in and out until you get the right speed.

Out of frustration, I drilled a small hole into the top of the speedo enclosure of the instrument cluster so I could insert a screwdriver. That way I could make the adjustments with the speedo back in the cluster and the cluster perched in it's mounting hole.

[Jimmy_GTT]

I have this 'speedo shows less' problem for quite a long time now.
But as I have megasquit in my car I could double check tacho and it also shows less.
I had a spare dash and it shows correct speed and rpm.
So I'll take my time and try to figure out what went wrong in my other dash.