Instrument cluster screwed

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OK, so I got my no-banana self into trouble again. I was going to pull my instrument cluster, and disconnected the lead from the battery, unscrewed the retaining screws and started to pull it out, but got a lot more resistance that I was comfortable with. I assumed it was the speedometer cable and I didn't want to screw with it too much, so I screwed the cluster back in and reconnected the battery lead. Now, unfortunately, the fuel gauge sits at full and doesn't go back to empty when I shut down, and the temperature gauge spikes up way too high when I start it.

Any thoughts on what I've managed to do?

Thanks, and apologies for newbing it.

Cheers,
prat
 
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'78 40.

OK, so I'd like to pull the cluster, but when I got it about an inch out I felt a lot of resistance. Is it safe to keep yanking or should I disconnect the steering wheel and try to disconnect the speedometer from underneath?

The oil pressure and amp gauges work fine, it's just temp and fuel.

Thanks for any help,
prat
 

Coolerman

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The speed-o cable clips, not screws, into the back of the gauge housing and can be reached (barely) by reaching up underneath the dash to disconnect it. Once that's loose it will come out a little more. Then there are the amp gauge wires and a circular connector to take loose. I bet the circular connector is partly unplgged...
 
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OK, got the fuel gauge working again. Coolerman, you were right: the circular connector was partially disconnected. Unfortunately, the engine temp gage still spikes the second I start the engine up, just idling. The radiator is hot but touchable and the engine block doesn't feel much more than just warm to me. Do you guys think it's a gage issue or not?

Radiator is topped off and the fluid looks normal to me. Anything else a no-banana guy can look at?

I'm going to let her cool off and then fire her up this afternoon to see if the temperature is still spiking.

Thanks for the help,
prat
 
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A couple of tips for removing the instrument cluster.

First, disconnect the battery

Second, loosen the bracket that supports the steering column. It should be a U shaped bracket that bolts to the bottom of the dash. This will give you some play in the steering column and allows the instrument cluster to tilt a little farther forward, giving easier access to the speedo cable.

As coolerman says, the speedo cable clips to the back and easily reconnects. Not really something to worry about. You should be able to reach it from the top, rather than having to wedge a hand in behind the dash.

Disconnect the circular multi plug and the amp gauge wires and you're ready for further disassembly. If you need instructions on further disassembling the cluster or want to see photos, PM me.
 

Coolerman

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OK, got the fuel gauge working again. Coolerman, you were right: the circular connector was partially disconnected. Unfortunately, the engine temp gage still spikes the second I start the engine up, just idling. The radiator is hot but touchable and the engine block doesn't feel much more than just warm to me. Do you guys think it's a gage issue or not?

Radiator is topped off and the fluid looks normal to me. Anything else a no-banana guy can look at?

I'm going to let her cool off and then fire her up this afternoon to see if the temperature is still spiking.

Thanks for the help,
prat

Check that the wire is clipped onto the temperature sending unit firmly. If it's loose, it will do what you are seeing. Pull it off, clean both the clip (not easy) and the post on the sending unit then clip it back on. It usually fixes the problem. ;)
 
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Spoke too soon: the fuel gage is still pegging at full. Not that I don't wish that were true.

I finally got to the sending unit (man that thing is deep back in there) and unclipped it, cleaned it with a toothbrush and hooked it back up, and pulled the instrument cluster a third time to make sure the circular connector was properly snapped on. When I fired the engine up cold it showed the engine as cold, but after about 5 minutes of driving it was heading back up to overheating. I turned the fan on, which brought it just back under the upper limit of normal. When I got home I turned her off and rechecked everying a fourth time (unhook battery lead, make sure sender is properly clipped, pull instrument cluster, make sure everything is firmly clipped and reassemble it.)

(btw, how cool is the teq on the exposed gauges?)

I fired it up again after the 10 minutes it took me to do that, and again the thermostat went to H. I just don't believe that: if it were that hot I'd be seeing steam from the radiator, right? Again the radiator was hot, but not iron hot.

So I'm still thinking it's an instrumentation issue. I'm going to get some electronics cleaner and really try to get the connectors gleaming. Anyone else have other ideas?

Thanks for all your help Coolerman. I bought this truck to learn on, so this is fun in its own way.

Cheers,
prat
 

Coolerman

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Can you get access to an accurate thermometer? Infrared type will do in a pinch (they are not known to be the most accurate things...) but the :princess:'s cooking thermometer will also work. Place the thermometer as close to the top thermostat housing as possible and tape it in place. Run the engine until it gets hot to see what the coolant temp coming out of the motor really is. It's the only way to know for sure. You can also install a good aftermarket gauge. :D
 
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I used to own a '70 that I had to fold up some alum foil into a little tiny square and stuck it into the clip to give a tight fit complete with contact. This was of course, after I cleaned the post and contacts inside clip.
This was back when chewing gum foil didn't have the inner coating... Regular kitchen al.foil would work.
If the fitting is already snug, please disregard.
 
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Coolerman, I think I can come up with a good thermometer. Thanks for telling me where to put it. (I'd have probably tried to stick it on the sender and then wondered why my truck was running at 80 degrees.)

gmarshall7, I should have tried that. d'oh!

Thanks for the ideas guys. The fuel gauge is still pegged as well, so I'm going with the idea that the problem is with the circular connector. I'll clean that out really well this weekend with electronics cleaner and then, when that doesn't work, bump this thread up to the top and embarrass myself some more.

I really don't want to put after-market gauges in. I love that crappy little instrument cluster. All I wanted to do was clean it!

Cheers,
prat
 

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