Help! 30 amp fuse keeps blowing

[mirrorman]

I replaced the guage cluster on my 79, installed new radio, ran new wires as previous owner had a mess.Radio now works fine except a 30 amp fuse keeps blowing.I've tried unplugging everything from the cluster curcuit plug,heat/ac,rear defroster etc. Still blowing.
Anybody have any ideas where to look.
Crazy in md.
I noticed when i turn the battery on the headlites don't open

 

[Hib Halverson]

If you have a fuse that keeps blowing...especially a 30 amp fuse...stop replacing it.

My suggestion would be to, first, obtain the factory service manual. Read the books' wiring diagram to understand the circuit protected by that fuse, then start testing to find the short.

As for the lights not coming on when you turn the battery on....the headlights on a C3 are deployed and retracted by vacuum not electricity. To turn the lights on, you pull the headlite swtich, however, to get them to come up, you either need the engine running.

 

[tmkassin]

Which fuse is it? Headlamp? Cigarette lighter? Heater...

 

[mirrorman]

30 amp fuse????

Don't know what curcuit it is.Can't read anything on fuse panel.
Someone might have the wrong one in.Tested with continuity tester and it seems to feed guages,cig lighter.Does anyone have a picture of fuse panel for 79

 

[Evolution1980]

Don't know if 1979 fuse panel and wiring is the same as 1980, but here's a few pages from the 1980 service manual, for whatever it's worth... (click on the attached image, then click again to have it go full screen (or into a new window where you can have it go full screen))

Doesn't look like any of them should have a 30A fuse...

 

[mirrorman]

I ordered a factory wiring diagram from classicwiring.com. It shows everything on (3) separate plastic coated panels.Everything is color coded so it was easy to follow.
Someone before me put in a 30amp when it should have been a 20amp.
After removing guage cluster i found a cluster of wires that someone put in for ??radio,amp or ?????.It seems that the cig. lighter was the problem,after removing wires not needed,and repairing lighter.
Everything is sweet again.
Thanks for taking the time to send 1980 diagrams.