ShckByte Posted August 20, 2012 Share Posted August 20, 2012 I tore apart my dash this weekend so that I could replace just the speedometer that stopped working forever ago. I put everything back together correctly (so I think/thought) and the gauge lights won't work to include turn signals. I changed the fuses because last time I had to tear apart my dash some fuses blew. This time it didn't make a difference. There was literally one wire out of all of the wires that I wasn't 100% sure of where it should go. It is a ground wire (blue) and I believe was just connected to the top of the left cluster gauge to a screw. I was careful not to mess with the computer-like sheet on the back of the cluster gauge (for lack of a better word). My turn signals still work though, but not my lights. Any suggestions from that horrible description of what was wrong? Thanks. Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 21, 2012 Author Share Posted August 21, 2012 To add to this, I tried seeing if I made all of the connections correctly and they seem fine. My speedometer is still reading high even after a new one and cable...could it be my transmission reading incorrectly? My gauge fuse won't light either when I use my meter. I turn on the headlights too and still won't light up...what could cause this? Quote Link to comment Share on other sites More sharing options...
monte70car Posted August 21, 2012 Share Posted August 21, 2012 Brian did you follow a car or go though one of those speed trap machines? How far off is your speedo? If someone changed the rear end gears or put a different size tire on it the speedo will be off and you would need to buy the right gears for the transmission Quote Link to comment Share on other sites More sharing options...
cbolt Posted August 21, 2012 Share Posted August 21, 2012 A good tranmission place should have no trouble swapping out the speedo gear for the correct one. As far as the lights go I would start with an inspection of the headlight switch. I believe there is supposed to be a ground strap attached to it. Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 21, 2012 Author Share Posted August 21, 2012 I will have to look into the speedo gear...don't much about any of that. It is like 10 plus miles off when I get past 30. Said I was going 100 on the highway, so obviously knew something was wrong...AND people were passing me, lol. There's a ground strap on the headlight switch? I do know that I have to push a little back in on the headlight switch for it to turn on. Luckily all of my blinkers work, just not the lights. I don't remember seeing any type of ground strap though. Doesn't mean there isn't though. Just the blue ground wire that I didn't know where it went. So I attached it to the top of the gauges to ground it. Obviously not a right choice. I will have to tear apart my dash again to see what works this weekend. Does anyone have a cluster gauge that is connected properly with pics by chance? That would be very helpful. I don't remember this one connector though (think it's for digital gauges or something) that is based off the main wiring harness. I looked everywhere where it could have gone, but didn't see anything. I'm sure it never was hooked up, but thought I should ask. I guess we have all had the same problem, unless we had our MC's in the family from day one, that a million different hands were on the MC for over 40 years and modifications made everywhere, thus you have to adapt! (referencing more so the speedo and speedo gear...who knew). Thanks! Quote Link to comment Share on other sites More sharing options...
monte70car Posted August 21, 2012 Share Posted August 21, 2012 You say its a blue wire does it come out of the harness and what does the end look like? The only blue wires I know in the dash harness is the turn signal lights and the oil light. If the lmps fuse has no power when the head light switch is pulled out I would check the head light switch for power. With you say the speedo is 10 mph plus higher I would look to see what rear end gear you have, this can be done by counting the number of turn of the rear wheel with the number of turns by the drive shaft. It sounds like the original speedo might have been fine Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 21, 2012 Author Share Posted August 21, 2012 The blue wire is just a ground, so not sure what it truly is used for. I have another wire on the other side that, I believe, is the ground too. How do you check the headlight switch for power? The headlights do work if that's what you mean. But as mentioned if you pull it out too far the lights don't turn on, you have to push it in a little to work. I guess over time of turning them on and off it is wearing out. As usual, everything worked fine before I took the dash apart. The original speedo also did the same thing, that's why I first changed out the cable thinking that was the culprit...then finally broke down and bought the actual speedo to install...note to self, if you ever just want to change ONE of the gauges, do it all at once! Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 22, 2012 Author Share Posted August 22, 2012 So does anyone have a pict where the ground should go on the headlight switch...not even sure if my gas gauge is working either because I accidentally touched it when opening the case. I'm sure that doesn't matter, but somewhere along the line, something isn't connected correctly. Quote Link to comment Share on other sites More sharing options...
monte70car Posted August 22, 2012 Share Posted August 22, 2012 When you put the head light switch back in you made sure the large metal eyelet was in front of the head light switch? The metal eyelet acts as the ground for the head light switch and its pop revited to the metal frame work for the dash. That is the only ground I know of for the head light switch. Now for the gas gauge did the cluster plug go all the way in, it will only go in one way in the cluster. Does the gas gauge go to full or to empty? You can test the gas gauge by unpluging it in the trunk and turn the key on the needle will move Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 22, 2012 Author Share Posted August 22, 2012 Ah, so much to learn and do...always been a body mod man...never the mechanics! I need to just look at what I have to understand what you are saying. I'd imagine the cluster plug you are mentioning is the one that goes into the left side (off the main wiring harness)...correct? If so, I pushed it in as far as I could...but to tell you the truth it seemed like there still was some space. I'll probably be pulling my hair out starting Friday evening through Sunday to get this right. Starting to stress me out considerably! Not good when you wake up at night thinking about it, lol. I guess next time I will take picts before I take something apart (like I was telling myself)...getting old(er) is fun;) Quote Link to comment Share on other sites More sharing options...
monte70car Posted August 23, 2012 Share Posted August 23, 2012 Brian here is some pictures I grabbed for a project I haven't even started yet . Here is how the plug should look but with the PCB This is a plug lay out for idiot lights top row the light blue is left turn signal(slot 1) grey dash panel lights(slot 2) brown generator light(slot 3) empty (slot 4) pink fused power for dash (slot 5) empty (slot 6). Bottom row tan fuel (slot 7) tan brake light (slot 8) dark green temp (slot 9) dark blue oil (slot 10) light green high beam (slot 11) dark blue right turn signal (slot 12). Now if you have the u14 style dash tach, amp, water temp and fuel gauge slot 3 will have a black/white wire for the amp slot 4 will have a black wire amp, slot 5 light green high beam, slot 6 dark blue oil, slot 7 pink fused power, slot 9 tach(runs though the fire wall to the - side of the coil) slot 10 dark green temp slot 11 tan fuel. Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 23, 2012 Author Share Posted August 23, 2012 Wow, thanks so much for the picts, that does help a lot. I will print these out so I can work on it tomorrow and this weekend. Quote Link to comment Share on other sites More sharing options...
stangeba Posted August 23, 2012 Share Posted August 23, 2012 Here is a picture of the back side of my 71 with factory gauge package. Perhaps this will help. I also had a problem that I think was related to my aftermarket left ft speaker interfering with the harness where it plugs into the PC. Picture Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 23, 2012 Author Share Posted August 23, 2012 Do you have the (as shown) a ground going to the cluster gauge? This is where I think I have one of the problems. Thank you for the pict. Quote Link to comment Share on other sites More sharing options...
ShckByte Posted August 23, 2012 Author Share Posted August 23, 2012 I see from the photo that the ground strap goes from the headlight switch, but I had a blue wire as well. Quote Link to comment Share on other sites More sharing options...
LostnFound Posted August 24, 2012 Share Posted August 24, 2012 Hmmm....you guys have me thinking. I wonder if we are experiencing same or similar problems? Bruce....I too have an aftermarket speaker with a nice big magnet close to the headlight switch. What did you have to do to correct the speaker problem Bruce? I'll check out this post again this weekend as I'm having my Monte Doctor check out my non-gauge-light problem tomorrow morning as well as a noisy starter. Cheers, Larry Quote Link to comment Share on other sites More sharing options...
stangeba Posted August 25, 2012 Share Posted August 25, 2012 Larry, I modified the mounting bracket somehow to move it away, but it still keeps the pad from sitting properly so it sticks up a bit. Bruce Quote Link to comment Share on other sites More sharing options...
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