rev counter issues

[p5coupepaul]

my rev counter on my p5b has a mind of its own
sometinmes it will work and other times not atall.
what could it be
someone mentioned a loose wire or connecter needs cleaning up
But where do you start??
cheers
paul

[petervdvelde]

Paul

I assume your rev counter itself causes the problem because it is switched in line with your ignition coil so if the problem is caused by your car wiring , the engine likely would stall

Peter

[p5coupepaul]

hi peter
funny enough I picked a nos rev counter up recently off a chap having a clearout.
ill try that
do you know if they are easy to change
cheers
paul

[petervdvelde]

Paul,

You have to remove the 2 screws on the underside of the dashboard housing. Then loosen the speede cable from the speedo meter(make sure the cable nut doesn't slide away as it could be difficult to get hold of it again (don't ask me how i know))) and then pull the front dashboard cover out. The rev counter is held by 2 nuts and can be easily removed.
Fitting the front dashboard cover can take some time as wires could be stuck between the cover and dashboard housing

Peter

[p5coupepaul]

thanks
peter for your helpful info
that looks like a job for next weekend
regards
paul

[Warwick]

Jul 24, 2016 18:10:01 GMT petervdvelde said:

... make sure the cable nut doesn't slide away as it could be difficult to get hold of it again ...

Before you loosen the cable nut, wrap a piece of electrical tape around the cable, a few centimetres below the nut. Use a piece of tape a couple of inches long and place the middle of it against the cable then squeeze it around until it sticks to itself (sticky side to sticky side) and forms a non-sticky tab. This will prevent the nut sliding very far and make it easier to refit the cable, but it won't get in the way or foul on anything.

Not sure I described that very well.

[cstorey]

If it is intermittent, but behaves normally when it does work, then the most likely cause is inadequate earthing . Usually, they are earthed by a black ring-ended wire attached to one of the fixing posts, and if the knurled nut which holds the bracket to the post becomes loose ( and therefore the ring end with it ) you will lose the circuit  which drives the needle from time to time - the positive half is provided by the green wire

[talbotspecial]

Hi Peter,
I bought a set of gauges from a Rover P5 to install them in my racer project.
My problem is: I don't know how to connect them, because there are no signs on the back of them. 
Could you help me out? I live in Belgium Sint-Niklaas, are you Attachment DeletedFlemish as well?

[petervdvelde]

I live in holland approx 40km from the Belgian border near Eindhoven.

I don't know what kind of engine you have. I assume it is a Rover V8. Then i should know if it is the P5B, SD1 or Range Rover ignition system. There are small differences between those ignitions with regards of how to connect the rev counter.
If you don't know which ignition system you have, please post a picture of the distributor.
And let me know what other 3 gauges are for.

Peter

[Deleted]

The rev counters are old electronics and components do fail,on a hot day my rev counter becomes rather erratic presumably do to a condensor or resistor getting close to failure as the temperature of it rises.
One thing I have noticed is that (assuming it isn't hot) that the instrument can indicate an ignition circuit fault with the needle swinging about.The other day a plug lead came off,as I looked for somewhere to pull in the rev counter was all over the place although the misfire was quite hard to notice at first.With the plug lead refixed things returned to normal.