Author Topic: Mark 2 Zephyr Temperature Gauge problems  (Read 222 times)

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Offline lowline

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Mark 2 Zephyr Temperature Gauge problems
« on: April 29, 2018, 03:41:25 AM »
My second car, a 1960 beige Zephyr is now completed except for a trip to the upholsterer for an interior.

The engine was professionally rebuilt and performs really well. I rebuilt the whole car from boxes of parts as it had been totally disassembled and so I thought that it would be wise to fit an auxilliary temperature gauge of the capillliary type. It shows the temperature at around 2ooF and I have verified it with an infrared gun.

My problem is that the gauge in the instrument cluster went all the way to the red on a couple of occasions and when I verified that it was in fact wrong, I removed the wire attached to the sending unit in the head for a few minutes then reattached it and it went back to being normal for a couple of weeks. Now within a few minutes of a cold start the gauge on the speedo cluster has climbed into the red line and stays there. I have changed the whole instrument cluster out to no avail, I have replaced the sender unit on the head with another used one from my toolbox . I have switched on the ignition and connected the clip to the on my test light to the ground on the battery and put the probe into the wire going to the sender and it shows a pulsing current coming out of the wire.

I am now completely at as loss as to the solution or how to test or interpret anything that is going on or should be going on.

Any advice would be much appreciated as I know absolutely nothing about electrics.

Thanks,
Bernie.

Offline Vauxhallbitz

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Re: Mark 2 Zephyr Temperature Gauge problems
« Reply #1 on: April 29, 2018, 11:39:32 PM »
Hello Bernie,

Hope you are well, sounds like you have been busy!

I can't help with this one but I am sure that Charlie or JD will be along soon.

Would be good to see some pictures of your car.

Take care,

Regards, Fraser.

Online JD

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Re: Mark 2 Zephyr Temperature Gauge problems
« Reply #2 on: May 02, 2018, 01:00:37 PM »
My second car, a 1960 beige Zephyr is now completed except for a trip to the upholsterer for an interior.

The engine was professionally rebuilt and performs really well. I rebuilt the whole car from boxes of parts as it had been totally disassembled and so I thought that it would be wise to fit an auxilliary temperature gauge of the capillliary type. It shows the temperature at around 2ooF and I have verified it with an infrared gun.
My problem is that the gauge in the instrument cluster went all the way to the red on a couple of occasions and when I verified that it was in fact wrong, I removed the wire attached to the sending unit in the head for a few minutes then reattached it and it went back to being normal for a couple of weeks. Now within a few minutes of a cold start the gauge on the speedo cluster has climbed into the red line and stays there. I have changed the whole instrument cluster out to no avail, I have replaced the sender unit on the head with another used one from my toolbox . I have switched on the ignition and connected the clip to the on my test light to the ground on the battery and put the probe into the wire going to the sender and it shows a pulsing current coming out of the wire.

I am now completely at as loss as to the solution or how to test or interpret anything that is going on or should be going on.




Hi Bernie, my first reaction is the sender is incorrect. The sender must be matched to the gauge,although I have seen people
advertising universal senders for sale - don't know if they work or not though  so I would stick with matching. From the temp gauge there should be a white/redtracer wire going to the sender on the cyl head.
this get a variable earth as the temp changes. If you remove the wire from the sender & connect it to earth, the gauge should go to maximum known as full scale deflection or FSD. If that happens with yours
it means the gauge is OK & the sender is the problem. As you are getting other (false)readings on the gauge I would guess the gauge is getting it's +ve feed OK. I think the +ve feed to the gauge was a black/blue tracer wire.  On another query, I have just purchased an alternator for my Zephyr & the pulley on there is 71mm, which looks correct to my memory. I have it fitted with the original belt but not yet connected for test - will let you know if it works OK at idle(or just above),cheers,JD.

Thanks,
Bernie.

Offline lowline

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Re: Mark 2 Zephyr Temperature Gauge problems
« Reply #3 on: May 03, 2018, 04:16:23 AM »
Hi, JD.

Thank you for your sage advice. I ran a jumper from the end of the red and white wire to the earth post on the battery (the polarity was changed years ago) and sure enough the needle went straight to the red line on the gauge.

The sender is the original Smiths one fitted when the car was built. I have tried another one from my other Zephyr (same problem) and one from a 1960 Zodiac that does not run and it was no better.

Do you know of any brand of aftermarket sender or a type from another car that might work or will I just have to leave the wire of the sender so that I don't get heart palpatations when I look at the stupid thing?

I look forward to any suggestions as the snow and salt appear to have gone this week so I will start getting the old car out and about again.

Thanks for your help, it is much appreciated.
Regards,
Bernie.

Online JD

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Re: Mark 2 Zephyr Temperature Gauge problems
« Reply #4 on: May 03, 2018, 09:45:30 AM »
Hi Bernie, try contacting demon-tweeks.com & explain your problem.
exportsales@demon-tweeks.com  is the most likely email address.
They sell a sender SMITT6811-01 which they claim is for Smiths classic gauges.
I would make sure before purchase. If the threaded hole in your cylinder head
is the large type you may need an adaptor to fit the sender. Cheers,JD.