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bigmal

Fuel, Oil and Temp Gauges not working again...ideas?

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Seriously, this car is doing my head in. When I first changed to right hand drive 18 months ago the fuel, oil and temp gauges would not work. Fitted a new Constant Voltage Regulator (CVR)…...still no good. After lots of trouble shooting and help from Midlife it turned out to be the terminal posts of the fuel gauge touching the instrument casing and shorting the three gauges. About 6 months ago the gauges stopped working again. After a few weeks I took a day off work to pull the dash and replace the CVR and see if there was another short circuit. I went to move the car and all gauges were working again and did so until today. I tried thumping the dash and that didn't help.

My question...…..is there something else that these three gages have in common that may be the cause before I pull the dash?

Also, is there any particular CVR that is better than others?

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Only grounding to the case, and the power output from the CVR is shared by all 3 gauges.  Your input power to the CVR or its ground may also be suspect; that is all there is. 

 

I've found that the resistor wire feeding the dash cluster pin needs to be re-crimped, as often times it reads well above the nominal 10 ohms from the ACC source at the ignition switch.

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On 2/2/2019 at 1:40 PM, Midlife said:

Only grounding to the case, and the power output from the CVR is shared by all 3 gauges.  Your input power to the CVR or its ground may also be suspect; that is all there is. 

 

I've found that the resistor wire feeding the dash cluster pin needs to be re-crimped, as often times it reads well above the nominal 10 ohms from the ACC source at the ignition switch.

I have your dash harness so have crimped this myself. Is it possible it is in the ignition switch?

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Possible...look for a thin purplish wire tied into the black/green thick wire at the ignition switch connector or at a large OEM splice above the switch connector.  Check to see what resistance you have been the ignition switch pin and the dash cluster pin: should be 10 ohms or so.  You can also check for voltage at the dash cluster pin: 12V, but the presence of voltage does not necessarily mean you'll have current due to high resistance.

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3 hours ago, RPM said:

There is a cure for your gauge issues...

122209319_gaugeclusterrearview.thumb.JPG.6167b658da1a5b7d4b20bd27647500cc.JPG

Contact MidLife for pricing :)

Thanks Bob, I already have this harness. Installed in 2027 when converted to RHD. A great mod. I also spent half an hour on the phone with him troubleshooting the problem when it happened back then.

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7 hours ago, Midlife said:

Possible...look for a thin purplish wire tied into the black/green thick wire at the ignition switch connector or at a large OEM splice above the switch connector.  Check to see what resistance you have been the ignition switch pin and the dash cluster pin: should be 10 ohms or so.  You can also check for voltage at the dash cluster pin: 12V, but the presence of voltage does not necessarily mean you'll have current due to high resistance.

Will try that on the weekend. Thanks 

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Drove the stang to the shops today and planned on trouble shooting the gauges when I got home. Got in the car to drive home and they are working again. 

I have the take the dash out to sort out the GPS tracker that has an issue so I will change the CVR while it's out. I have a spare so worth a try.

I love intermittent faults. they're the best!

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It was back to not working again so I began trouble shooting yesterday. Took out the instrument panel and checked for a short between the instrument posts and the body pf the panel. Nuts were loose on one gauge but not shorting. Tightened them and tried it but no good. I had the original CVR that I changed when trouble shooting two years ago so I put that in.

FIXED!!!.

It was the cheap dodgy Chinese rubbish CVR. The 50 year old one works a treat.

The Midlife harness makes it so easy to work on the panel. The loom is long enough I can have the panel right out and still have it connected. That alone makes it a great mod.

Thanks for the help guys

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