18 replies to this topic

[Marky Tizz]

Model:MINI THIRTY
Year:1989
Description of problem (please be as in depth as possible):
Hi everyone, just fitted my new starter motor and it reminded me of the problem I've been having with the tachometer. It works incosistently - although it knows when the engine is running/idling, it won't show above 2k rpm and gets there very very slowly, despite the fact I'm clearly doing around 6k (25ish in 1st, maybe not 6k but certainly not 2k), sometimes after a long drive it will start working again, but now it's hardly ever working.
I've checked the connections on the back of the tach and they seem fine, so I'm wondering if it's a problem in the engine bay?
where does it or should it attach, etc etc.
Suggestions please
Thanks a lot.


Any non-standard parts that might be involved with the problem?
Nah boys.

[Marky Tizz]

sorry for the fairly early bump but its 2nd page already and I need to know

[JD8891]

Do your windscreen wipers work and park properly?

JD

[Marky Tizz]

ocassionally, theyre troublesome too. fitted a new park switch and it made them work sometimes.
why, are the two related?

[dklawson]

Only God can explain how the two are related. Taffy normally posts that question about the wipers. He's apparently seen the wiper park circuit cause tach problems multiple times.

[rallymini1972]

Hi everyone, just fitted my new starter motor and it reminded me of the problem I've been having with the tachometer. It works incosistently - although it knows when the engine is running/idling, it won't show above 2k rpm and gets there very very slowly, despite the fact I'm clearly doing around 6k (25ish in 1st, maybe not 6k but certainly not 2k), sometimes after a long drive it will start working again, but now it's hardly ever working.
I've checked the connections on the back of the tach and they seem fine, so I'm wondering if it's a problem in the engine bay?
where does it or should it attach, etc etc.
Suggestions please :)
Thanks a lot.


I fiited a Smiths one I bought off Ebay, and it connects to the coil and then to earth, check you have a good earth!? it may not work the same. I google'd smith rev counters and finally found pics and explanations of how to wire.
Dan

[Marky Tizz]

well everything else is earthed and works fine, so it's a mystery. Might be time to swallow my pride and get a new fusebox even though mine looks fine Keep the suggestions coming as I'm sure it's a problem elsewhere though.

[dklawson]

I fiited a Smiths one I bought off Ebay, and it connects to the coil and then to earth, check you have a good earth!? it may not work the same. I google'd smith rev counters and finally found pics and explanations of how to wire.
Dan

All electronic Smiths tachs I'm familiar with will have a switched power and an earth connection on the case.

RVI type tachometers (current pulse sensing) will have two wires/connections that go in series with power to/from the coil.

RVC type tachometers (voltage pulse sensing) use a single wire connection to the distributor side of the ignition coil.

The type of tach (RVI or RVC) is typically printed somewhere on the Smiths gauge face.

Please photograph (or sketch) and post your wiring that has a coil connection and and an earth connection.

[JD8891]

The wipers and tacho are connected if you use the wiring in the loom for the 12volt feed If you have ran a new 12volt feed from the fuse box check all the connections. I've had first hand experence of the wipers not self parking and the tacho not working. Fixed the wipers and the tacho started working again.

JD

[Marky Tizz]

Standard tacho so could be that. Bought a new fusebox off fleabay for £9 today so gonna try that out, taffy keeps telling me my fusebox is naff everytime I bring up an electrical thread so that's my first logical step. If that doesn't fix it though I don't know what will as I've already changed the park switch and loom section for the wiper motor.

[JD8891]

I did the wiper loom and park switch about 6 months before my tacho problems but changed the park switch again still didnt work so i cleaned up all the connections and hey presto it worked again so check all the conections are clean.

JD

[Marky Tizz]

OK I will check that also when I put the new fusebox in. Does anyone know where the read is taken from? Is it from the ignition coil like aftermarket tachs? If it is, where on the coil is it?
CHeers.

[Marky Tizz]

New development!
Today I was driving along and the tach was working fine so I thought i'd try the wipers and see if they'd started working.
NO! the tach STOPPED working while the wipers were moving, and once I stopped moving the wipers the tach went back to not reading above 2k again.
How very odd! How are they linked, someone tell me PLEASE its making me crazy!

[JD8891]

SELF PARK SWITCH!! they all share the same 12volt feed so when the self park switch plays up it causes havoc and possiblely a short cirucit and fire!

JD

[Marky Tizz]

But it's a brand new switch :'(