Gauges stop working then begin working again

[zdude1967]

I have a 74 260 and a few times the Tach, temp, fuel and oil pressure gauge have stopped working and then just started working again - the Amp gauge however did not stop, it continued to work while the other gauges took a nap. Anyone have any idea what may be causing this. I do have the crane ignition which plays a bit of havoc with my Tach (it makes it erratic).

 

Any thoughts why this is happening 

[Zed Head]

There's a fuse.  Could be losing contact. 

p.s.  just realized that I found an error in the FSM,  Check the bottom of the page and the label on the gauge in the diagram.  The bottom of the page is correct.

Edited June 6, 2020 by Zed Head

[zKars]

I’ve seen too many glass fuses that look great, even test great, but if can twist either end cap even a little bit then it’s got a crappy internal connection that is about to fail.

[SteveJ]

The first things to do:

1. Check the fuse as @zKarspointed out.
2. Consider trying to clean the fuse contacts. (Disconnect the battery before attempting this.) Roll up a small piece of 800 to 1000 grit sandpaper and rub it where the fuse box holds the fuse, or use a wire brush on a dremel tool.
3. Take apart connectors C-3, C-4, and C-5 and spray them liberally with contact cleaner such as Caig Deoxit. They could have seen some corrosion from water infiltration.

[zdude1967]

Thanks everyone for the input - I will get to work on this ASAP

 

 

 

[YZFMax]

I had the exact same issue, ended up being a bad fuse connection.  Seems like over time, the connections became a bit lose, so I pressed them in to create a tight fit for the fuses.  This resolved the issue.

[zdude1967]

Thanks- cleaned the connector and it seems to be better. However I noticed that my A/C fuse in the fuse box- 2nd one up from the bottom on the right is very hot. I was running the fan which only works on the low setting and the fuse becomes too hot to touch. It is an A/C car with the A/C components removed. Since the fan only works on one of the three speeds do you think that is the reason for the fuse to be so hot?

[Mark Maras]

Resistance causes heat at the point of resistance. If the blades that hold the fuse are clean, take a look underneath it. Frequently the soldered wire connection to the blades needs resoldered.