1970 Cuda, original Rallye dash. All gauges work correctly. Turn signal and parking brake dash lights work. Dash Reverse lights works. Dome light works. Headlights, tail lights and road lamps work. Flashers work. 3-speed wipers work. Dimmer switch rebuilt. On the fuse block, the upper right hand fuse marked "instruments" has no power to either side of the fuse, key on or off. Any ideas where to look next or what connections to check? I'm at a lose. :help: :clueless: :dunno: :huh:
Check the back of the fuse block , there is a power bar that feeds all of the fuses on one side of the fuse block , there has to be a problem there or corrosion in the clips holding the fuse
Thanks, Chryco, I'll check that next.
:bigthumb:
you have to have power to the contacts on the center row of the fuse block
I had the same problem. Mine was the dimmer switch. You can pull the plug off the back and put a jumper in to see if your light come on. If they do, switch needs to be cleaned or replaced.
That 'Instrument' feed comes from the dimmer switch. It's separate from the rest of the fuses. I'm thinking you have an issue with the dimmer switch. Check to make the sure the connector on the back is secure for a start.
Says his dimmer was rebuilt but it may still be the problem
Quote from: Chryco Psycho on May 21, 2019, 09:25:38 PM
Says his dimmer was rebuilt but it may still be the problem
Ya, I agree. But the instrument fuse gets power from the dimmer switch and he said there was no power at the fuse. So since the dimmer has been rebuilt I was thinking maybe the dimmer got disconnected somehow?
Quote from: edison1970 on May 21, 2019, 07:33:51 PM
I had the same problem. Mine was the dimmer switch. You can pull the plug off the back and put a jumper in to see if your light come on. If they do, switch needs to be cleaned or replaced.
Edison1970, which plug are you referring to? There are two plugs on the back of the dimmer switch.
Quote from: Chryco Psycho on May 18, 2019, 05:17:57 PM
Check the back of the fuse block , there is a power bar that feeds all of the fuses on one side of the fuse block , there has to be a problem there or corrosion in the clips holding the fuse
Chryco, the power bar stops just below the instrument light fuse. Power bar circled in red. Fuse in question circled in blue. Please see pics.
Quote from: usraptor on May 22, 2019, 11:47:15 AM
Chryco, the power bar stops just below the instrument light fuse. Power bar circled in red. Fuse in question circled in blue. Please see pics.
The fuse in question gets it's power from the dimmer.....not the fuse block power bar.
Pull the plug off the dimmer on the dash. Its a three wire plug. Put a jumper from the center to the one with the yellow wire. If the lights come one, the dimmer is still not working.
Here is a picture
Quote from: usraptor on May 22, 2019, 11:47:15 AM
Quote from: Chryco Psycho on May 18, 2019, 05:17:57 PM
Check the back of the fuse block , there is a power bar that feeds all of the fuses on one side of the fuse block , there has to be a problem there or corrosion in the clips holding the fuse
Chryco, the power bar stops just below the instrument light fuse. Power bar circled in red. Fuse in question circled in blue. Please see pics.
Got it :twothumbsup:
Sorry to mislead you :sorry:
just going from memory from a decade ago , no wiring diagrams here at all .
so the problem has to be power from the headlight switch or the dimmer again
Make sure that your switch panel is grounded. Many times people leave the screw out that completes the ground. If you are testing the switches with the panel not mounted just use an old alligator jumper lead from the area that is circled red to a good body/chassis ground. see attached
Okay, so after playing around with some connections and wiggling wires I now have power to the "instrument" fuse block. However, I don't have power to the other side of the fuse with a good fuse and clean connections. So I'm assuming that I don't have a good ground/connection on the other end. There are two orange wires coming off the dead side of the fuse block. Above the radio, where the single orange wire for the dash lights comes down is one of those three prong "accessory" plugs that has two orange wires going into it so I assume that is the same two orange wires that come out of the dead side of the fuse block and is the plug the dash lights plug into. However, there is no power to this plug, with ignition on or off and headlight switch on or off. Even with the dash light male plug plugged in there is still no power to the plug. So does this mean my dash light assembly is not properly grounded? Or is there some other issue? As I'm sure you figured out by now, electronics is not my strong suit.
You do not have a good fuse. If you have power on one side of the fuse, but not the other, the fuse is blown.
How are you determining whether a connector or fuse has power?
Quote from: dodj on May 23, 2019, 12:08:12 PM
You do not have a good fuse. If you have power on one side of the fuse, but not the other, the fuse is blown.
That's what I thought, but I've put in three different fuses with the same results. I have Power from the dimmer switch but it doesn't cross over to the other side of the fuse??? And yes the connections are corrosion free. I would assume for the power to cross over the other side of the fuse/wires need to be grounded, but as you can obviously tell I'm not a very good electrician.
I would venture to guess that either the rivet holding the fuse clip is corroded, or the fuse clip where the fuse plugs in is corroded...
I'd take some 600 grit wet-or-dry wrapped around fuse and polish up the fuse clip Inside Diameter that holds the fuse... do each side.. if still no power to other side, then it's the rivet to clip connection...
Well once again, the 'Cuda proves to be an idiot! :bricks: :headbang: Dodj you were 100% correct about the fuses. Because they were small 3AMP fuses I couldn't see that they were blowing as soon as I turned on the headlights. After I had unplugged the dash light bar from the three prong plug, I decided to throw in a 25 amp fuse just to test the circuit and found that I now had power to both sides of the fuse with the headlights on. As soon as I plugged the dash lights back in the 25 AMP fuse blew which I could easily see. What little electrical knowledge I have :idea: then told me that I had a short circuit in the dash light wire. I removed the dash light bar and discovered that I had pinched the wire on a sharp edge of the light bar and cut through the insulation down to the copper wire. I taped the cut insulation, re-routed the wire more carefully and reconnected the feed wire and I now have dash lights. :D Still don't know why I initially did not have power to the fuse block from the dimmer switch but as I stated earlier after I checked connections, wiggled some wires and re-seated the plugs I suddenly had power so obviously I didn't have a plug tight to start with although they sure looked like they were. Anyway, problem is now resolved. Thank you to everybody who chimed in with suggestions. They really helped my electrically challenged brain troubled shoot the issue, one step at a time. What did people do before the internet?
Also, I'd like to give out a big shout out to Jim at JS Restorations who did the restoration of my original dimmer switch. When he saw my post here he immediately reached out to me via email and offered to troubleshoot the issue with me over the phone. We first went back and forth via email with a few ideas and then this morning he overnighted me another dimmer switch to try. Fortunately with his and everybody elses help my pea brain figured the problem out today before the dimmer switch arrived. I called Jim back and thanked him for his diligence and willingness to help me and told him I'd return his switch ASAP. Great guy who knows his stuff. If any of you have an electrical issue and/or need a switch/part restored, Jim is your man.
Or it could be that... LOL
:bradsthumb: :cheers:
It's great hearing about vendors that are so willing to help out! Thank you from all of us, Jim at JS Restorations!!! Awesome service deserves more and return business!
:clapping:
Glad you got it sorted out.
As for why you got the power back for the instrument fuse, sometimes a connector lug is loose in the plastic connector and doesn't make a good solid connection. Look at the rear of the dimmer switch plug to see if one of the gold connectors have slipped back within the plastic a little more than the others....if you can contort yourself enough to get a look...
This thread reminded me I need to get Jim to do up one of my dimmers. I have 5, all a little inconsistent.....
Thanks for the great post. This may have fixed my problem also.