I have a 1967 Mustang Conv 289. Only driven once a week to make sure everything is working. Lately, when I turn it over, all the gauges are pegged on high - gas, oil pressure, and temperature, and stay there until I turn off the engine.
Then they all slowly return to the low side where they belong. It appears to me to be an electrical *short* but maybe I'm wrong.
Can anyone shed some light on this problem, or suggest where to begin to look.
Thanks in advance,
Matt
you could have a loose ground
Good suggestions all around, thus far..... what I would do....
Verify charging system operation... a poor ground or faulty voltage regulator could be raising system voltage too high.... This would be a simple test with a DMM across first the battery terminals, key off to establish baseline volts.... start the engine and compare the new reading to the first. FWIW, anything over about 14.5 volts is going to start dancing with the devil.... rev the engine to about 2000 and take a third reading.
If the charging system checks OK, test the CVR on the back of the cluster....
On the back of the dash, there's a small box with two posts. Looks like a circuit breaker. The gauges work on 6v, and that little box steps the voltage down from 12-14V, down to 6V. That keeps the gauges nice and steady despite voltage fluctuations. I would check that first.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.