If you have an HEI distributor with a Tach Output you can use the Tach Output from the distributor. Due to the high voltage of the signal from the HEI you should use a tachometer filter to prevent damage to the tachometer. Coil Pack or Individual Coils (Distributorless Ignitions).
Yes, thyroid disease can affect your mood â primarily causing either anxiety or depression. Generally, the more severe the thyroid disease, the more severe the mood changes. If you have an overactive thyroid (hyperthyroidism), you may experience: 1  Unusual nervousness. 2  Restlessness. 3  Anxiety. 4  Irritability.
All cells in the human body will respond to changes in thyroid hormones with a change in the rate at which they work. A lack of thyroid hormone, hypothyroidism, has long been linked to cognitive and memory problems and mood disorders, possibly through the brain chemical serotonin.