Rev counter generator

Technical advice Q&A
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Stevemorris
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#1 Rev counter generator

Post by Stevemorris » Fri Jun 05, 2026 6:21 am

My rev counter isn’t working, even if I tap it!

I’ve checked across the terminals for a Voltage, zero…

I did hear or read somewhere that you can get these re magnetised, does anyone know where or indeed if it’s possible?

Thanks, Steve.
1973 Rolls-Royce Silver Shadow
1965 Jaguar ‘E’ Type FHC

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tim wood
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#2 Re: Rev counter generator

Post by tim wood » Fri Jun 05, 2026 7:59 am

Is it definitely rotating? Not unknown for the drive dog to become distanced from the camshaft

Tim
Series 1 FHC purchased 50 years ago. Courted my wife in it.
Series 1 2+2 when the kids were small now sold.
Series 1.5 OTS in opalescent maroon, Californian car. My retirement present.

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mgcjag
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#3 Re: Rev counter generator

Post by mgcjag » Fri Jun 05, 2026 8:07 am

Or to snap off
Steve
69 S2 2+2 (sold) ..Realm C type replica, 1960 xk150fhc

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#4 Re: Rev counter generator

Post by Stevemorris » Fri Jun 05, 2026 8:09 am

Thanks chaps,

I have to remove the rearmost cam cap to renew a stud, so I'll check when I do this, and let you know! The drive is still intact Steve I took it off to renew the seal, it is spinning as well, plus I could feel the coupling in the cam and it felt OK?

Steve.
1973 Rolls-Royce Silver Shadow
1965 Jaguar ‘E’ Type FHC

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Simonpfhc
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#5 Re: Rev counter generator

Post by Simonpfhc » Fri Jun 05, 2026 2:03 pm

The generator creates an AC voltage that increases by 1v every 1000rpm. You could try measuring the output first.
Simon
62 3.8 FHC
91 Porsche 928GT
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Stevemorris
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#6 Re: Rev counter generator

Post by Stevemorris » Fri Jun 05, 2026 4:05 pm

Hi Simon, yes already done that and at 1,2,3,4000rpm zero Volts!

Thanks,

Steve.
1973 Rolls-Royce Silver Shadow
1965 Jaguar ‘E’ Type FHC

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