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HELP..Speedo Not Working

Posted: Mon Aug 22, 2016 3:35 pm
by JSM1965
HI All,
I am seeking advice & guidance on a problem I have with the speedo on my late 76 c3. It didn't work when I bought it but expected it to be the sensor.
So I've changed the sensor & get a pulse when I check the connector in the tunnel. Still didn't work
So I checked all of the fuses, all presented a reading.
So I checked I was getting 12v to the speedo, I was & am
So I sent off the speedo to a chap called Simon Hanlon thinking it was an issue with a worn cog or an electrical issue. He ran it up & it worked fine up to 150 mph, he put 4 miles on the clock. He didn't charge me other than postage & I gave him money for his time.
Put the speedo back in today & nothing.
So I have done all of the checks above & still nothing.

Any advice, further checks I could do, guidance all gratefully received

Thanks & Regards

John

Re: HELP..Speedo Not Working

Posted: Mon Aug 22, 2016 5:07 pm
by Lightweight_911
Is the speedo earth connection making good contact ?

Re: HELP..Speedo Not Working

Posted: Mon Aug 22, 2016 5:26 pm
by JSM1965
Andy I think so, do you mean the bayonet in to the lug ? This is how it looked when I first pulled out the dial

http://s1243.photobucket.com/user/JSM81 ... sort=3&o=0

Thanks & Regards

Re: HELP..Speedo Not Working

Posted: Tue Aug 23, 2016 9:11 pm
by Lightweight_911
Just a thought - is the speedo sender fitted the correct way round in the gearbox ?

It's not unknown for them to be incorrectly fitted - in which case the speedo wont work.

The side with the 2 'protrusions' should be facing outwards.

Re: HELP..Speedo Not Working

Posted: Tue Aug 23, 2016 9:17 pm
by Lightweight_911
Found a picture - the side denoted by the red arrow should face outwards:


Image

Re: HELP..Speedo Not Working

Posted: Wed Aug 24, 2016 6:46 am
by JSM1965
HI Andy, I will check but I think by jove you may have it. I remember thinking which way but to me it seemed that the side with the protrusions but also had insert holes would face inward & it did fit snugly

Thanks & Regards

Re: Success..Speedo Now Working

Posted: Wed Aug 24, 2016 9:01 am
by JSM1965
HI Andy, big thanks, a swap round of the sensor & it now works. It now makes me think I replaced a perfectly serviceable sensor as I did a like for like swap. Hey ho at least that's one job done.

Thanks & Regards

Re: HELP..Speedo Not Working

Posted: Wed Aug 24, 2016 10:04 am
by Lightweight_911
:cheers: Great news !