Sometimes when gauges don't work, it can take the fun out of driving old cars. None of us likes to be left along the side of the road because we forgot that the gas gauge measures 1/4 full but it really means empty! Some of the gauges on our '53 Buick didn't work, so, with our interior out at the shop, and our dash and window moldings apart, we had easy access to remove our dash gauges. Buick Roadmaster dashboards of the period had a di-noc decal on them to simulate a machined look. It was color-matched to the car. Our car has red and black leather interior, and a black dash top with a red machined bottom. The top needed to be repainted, but fortunately, the machined part was in excellent shape. Before repainting the top, we decided to remove the gauges, radio and clock for repair. We knew the speedometer had problems by the way it chattered and the needle jumped between 35-45 mph while we were driving. To find the problem, we tested the cable. First we removed it from the back of the speedometer, and jacked the car up to get the rear wheels off the ground, then started the car, put it in Drive and watched the inside of the cable turn. It moved quietly and in steady relation to the rpm's. The problem, then, was in the speedometer head. With the car in Drive and the rear wheels off the ground, we ran the engine revs up. At 35 mph, the needle jumped and we could clearly hear the chatter from the head. We removed it from the car and boxed it with our non-working clock, and sent both to our buddy Bill at the Clock Doc for repair.
Our radio also didn't work, but was complete and in excellent overall condition. Even the date stamp (Dec '52) and info tag were in good shape. On these old tube-type radios, the vibrator tube should buzz when the radio is turned on. Ours didn t. We did the simple test of checking the fuse and tapping the vibrator, but no buzz. So, the radio was removed and sent off for reconditioning.
Next was our ignition switch cylinder. There was no key, and the cover plate was dented. We found a replacement at Buick World. To remove the defective cylinder, we drew a center line on the cylinder at 90 degrees to the key slot, inserted a GM ignition key, and made a prick punch mark on the center line 3/8" from the side of the key. We drilled a .0465 hole through the cylinder flange, and inserted a paper clip end into the drilled hole to pry the cage bar assembly down so that the lock cylinder could be turned. After turning the cylinder slightly, we removed the wire to avoid wedging, then removed the lock cylinder by turning clockwise. To install the new cylinder, we inserted the new key, placed the cylinder in the switch housing slightly clockwise from the off position, and pressed inward and turned the cylinder counter-clockwise. The switch now looks and works great.
Our charge indicator worked, but we removed it for cleaning and checked the wiring. It is different from an ammeter, in that it shows plus and minus current, but is not graduated in amperes. It shows charging or discharging, but not the amount of current flowing.
The temperature gauge is not electrical, but rather is a vapor pressure type that makes use of a sealed-in liquid that expands, creating pressure that moves the pointer on the gauge. The sending unit is on the engine head s right rear corner. The sender extends into the cooling system s water. The heat of the water causes the sealed-in liquid to expand with the temperature and moves the gauge from Cold to Hot. Our gauge worked, so it was only removed for cleaning, but we replaced the sending unit because of age.
The oil pressure gauge is also not electrical, but is the pressure expansion type that makes use of pressure developed by the oil pump, acting directly on the mechanism of the dash gauge. The gauge is connected by a pipe to the main oil passage in the crank case, near the distributor, and registers the full pressure of the oil pump. Our gauge worked well, so we removed it for cleaning only.
Our gas gauge, however, did not work, so we checked the dash and tank sending units. The first check was the wiring on the dash gauge, which was found to be in good condition and wired correctly. The wire between the dash and tank unit was checked for continuity with our multi-tester and was shown to be good. Next, we checked the dash gauge. To do this, we first turned off the ignition switch and disconnected the battery. We have an extra good AC tank sending unit that we use for testing, and this we connected with a jumper wire from its center post of the dash gauge, grounding the tank unit to the car frame. We re-connected the battery, turned on the ignition switch and moved the float arm back and forth slowly. The dash pointer moved from Empty to Full, indicating a good dash unit. (Note: If the gauge indicates Full at all times, it might be due to a bad tank unit or a break in the dash-to-tank wire, or a bad ground.) By eliminating the dash unit and wiring, we knew our trouble was in the tank unit and replaced it. To calibrate it, we bent the float arm as indicated in the instruction sheet, then checked its lowest travel by moving the float arm which showed Empty on the dash gauge, and its highest travel which indicated Full.
Now all of the gauges work and we know how much gas we have when we re out for that Sunday drive. See you next month...keep 'em driving!