[strummin67]

Yesterday morning my wife and I were driving south to the Carmel Art & Wine festival. It was misty most of the way so I had my lights on. About half way there I noticed my tach isn't working. It also appears that my dash gauges are no longer illuminated. I pulled over and sure enough no tail or brake lights. Blown fuse. We made it down and I picked up some fuses at a hardware store and I put the replacement in.

That evening as we're headed home, the same problem came up. Made the two hour drive home but I'm still scratching my head as to why I keep blowing fuses. Any ideas where to start?

 

[chevyIIheavy]

you maybe over loading that circut the headlights put a lot of load on the electrical system you may need to put in a relay of some sort to take some of the load off of that circut also you may want to put in a bigger fuse ( one with more amps )

 

[The Big Al]

Does the vehicle have a trailer hitch? trailer wiring?

look around the tail light wiring. (this is a I would start first)

trace the wires in the engine compartment going to head lights and running lights.

Do you have gauge lights tapped into the light system?

And it could be a bad headlight switch causing it.

Just some ideas of where to start!

 

[strummin67]

No trailer hitch but I do have three gauges hooked up to the dash lights. I looked at as much as I could see this morning under the hood an dash and nothing looks out of place. I tried to replicate the situation this morning with lights, wipers on but the everything stayed on. Thanks guys for your suggestions.

 

[Custom Jim]

I'm going to start with two statements.

Never replace a fuse with a larger one unless you know what is going on.

I do not know a whole lot of the older vehicles wiring circuits.

That being said, make sure the fuse that got replaced is of the correct value. Don't assume what was in there was correct.

On the problem did just one fuse blow ?. If the tach went dead the the dash lights also went dead I would think these would be on two different fuses. One would be an ignition fuse to power up the tach so it works only when the key is in the run position and another fuse off of the dash dimmer circuit to where when the headlights/parking lights are turned on the light in the tach would light up and also be a variable brightness depending on how the headlight switch is rotated.

If there are two fuses that were blown (ignition and dash lights) then I would be looking at things that share these connections like an aftermarket tach. Another added thing that might also be tied to these two circuits would be aftermarket gauges and possibly audio systems.

If you have things ties into the fuse block try disconnecting them and see if the factory fuse blows after a while (and after driving as sometimes problems will not show up with a car sitting still). If after some time the fuse does not blow, plug in one added item at a time until the fuse does blow and then on the wiring to this item, look at it for any shorts or pinched wiring. If there are no pinches or shorts then there could be a problem with overloading the fuse or an internal problem on this item (tach, gauge, whatever).

Jim