Packard Forum Index » V-8 (1955-56)

So not even a week in my possession and I broke something.

I was pulling the speedometer cable on my 55 Patrician to get some graphite on the line to help out a bouncing needle. I must have loosened something up when I had my hand up there because now my oil pressure and temp gauges aren't working....and I didn't even fix the speedometer!

So before I have nightmarish visions of a dismantled dash in my car, has anyone else experienced a similar issue and can maybe give me a tip as to what I screwed up and how to put it back to normal?

Or maybe tips of what to look for, it's hard to really be clear on what I'm seeing in such a cramped space.

The gauges run on a voltage regulator which reduces the 12v down to 5v. On a senior car it runs the temp, gas and oil gauges. It is located on the bottom of the cluster on the back of the speedo case and has to be grounded to operate. If you removed or loosened any screws make sure the regulator has a good ground. Also, it is possible one of the wires broke off the regulator so check that the gauges are connected. IIRC, a wire comes down to the regulator from the two top gauges and the third gauge connects to one of the others. The other terminal on the regulator goes to the fuse block and is the instrument cluster fuse. Assuming the key was off and nothing was powered and fuse is not blown, it is also possible the fuse is not making good contact in the holder. Oxidation build up on the holders and fuses with a resulting bad connection can sometimes be a problem with long sitting cars.

The arrow points to the regulator.

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Once again, advice from this forum has warned me before I could do something I'd regret. Howard's advice on being delicate with the 67 year old wiring on my 1950 will now be extended to anything that I do with either of my 1956 cars. I have made a very large mental note to disconnect all battery power before any poking around is done. A smaller mental note will be to get all uncomfortable, lying on my back under the dash so that you can plainly see what you're doing rather than doing it by feeling around for nuts and fasteners. Inadvertently pushing old wires and straining old connections could get expensive, even without causing a fire.

Many of our more modern cars have their airbag components colored in bright yellow, the wires included. Manufacturers and mechanics emphasize the importance of powering down by disconnecting the battery and waiting minutes before working on or around these yellow things so that they are not accidently deployed. I will extend my own caution to any underdash work by making sure nothing can be energized when working under the dash of any old post-war Packard.

One other thing on your bouncing needle. There is an oil hole for the bushing holding the piece with the square hole the cable connects to. After 60+ years that bushing is most likely dry and is frequently the cause of the bounce. The oil hole is located in the square protrusion on the casting. On that speedo, it is directly below the screw you see immediately above the threads and, IIRC the screw may need to come out to access. Possibly you can use one of the needle type oil applicators and leave the screw in place. Some parts and hardware stores have the applicators and they are also commonly found with sewing machines and the like. There is a felt wick in the hole so add a few drops of light machine oil but don't get carried away. It might also stand a drop or two at the end in the area where the rotating piece enters the casting.

Brilliant, thank you. It's hard to visualize without actually knowing what is back there...and I think you may have hit it, I must have done something to the ground.

Dave - wise advice and I will admit advice I didn't follow. I was lucky this time, and next time that batter is getting disconnected. It's so hard to figure out how exactly to position ones self just right to be able to see up in there. Definitely going to need a light and potentially muscle relaxers lol

Thanks, Howard! Man, maybe it'll just be best to get it out of there and do the work. But one thing at a time and slow and steady.

Ok, so I've been out of the country for 2 weeks and I know this weekend instead of resting I'm probably gonna get the bug to get that gauges working again. For the life of me I can't find an instructional either in the workshop manual or by searching past posts that outlines how best to access or view the back of the cluster.

Ideally I'd like to not remove it from the car and fix it in place, that way I can still drive it in case I can't fix it and have to resort to sending it to someone to do for me.

Be thankful you do not have factory air or you really would be using or learning new words trying to access the cluster while working in the confined space.

The cluster attaches to the back of the dash so no screws in front to remove and bring the cluster out. The wiring is also wrapped around braces or connected to switches so even if the cluster unscrewed it would not move very far. About the only description and photos you will find are in section 13 of the 55-6 service manualhttps://www.packardinfo.com/xoops/html/downloads/servicemanual5556/Sect13_Instruments.pdf and a few more photos showing more of the back of the entire dash in the field install instructions for the 55-6 factory AC system.https://www.packardinfo.com/xoops/html/downloads/55-56ACInstall.pdf

Short of removing the dash -- a major project and only helpful if doing other work, the only other access is to find a comfortable way to work while laying down and reaching up and under the dash. You can do as most do and kneel on the ground and contort yourself. If you anticipate an extended session such as when rewiring you can drape yourself over or even remove the front seat (a project in itself because it is heavy) or use some cushions to raise the passenger side floor to the height of the hump and lay on your back from that direction. You could also make some kind of platform and extend yourself out the drivers door. None are comfortable positions and something will always be in your way. Good lighting under the dash such as several of the new and small LED lights are a big plus.

I usually remove the front seat so I can lay lengthwise in the car. I get a lot better position to get at the gauges that way.