Frustrating, tedious, but problem solved (I think and pray). And THANK YOU
@scotts90ranger and
@Curious Hound - without all your input and bench testing and images, etc., I’d probably still be scratching my head wondering why it doesn’t work.
I put 1.5 V on the old/no tach speedo and set it at 40. As I connected and disconnected the wires, it would come back to 40 MPH. That’s with the speedo sitting upright in a vice.
Then I put the new/tach speedo in the vice and checked it with the 1.5. Needle rose to 40 where I had set it before.
Remember, test drives through the school radar warning signs showed I was running about 7 mph higher than the speedo was reading.
Then, crazy time. I invested $11 in eight Ever ready energizer batteries, brandy new. I usually buy 24 for less than that at Harbor Freight. Anyway, as I was fiddling, after the initial check, neither speedo would climb sitting vertical. So I flipped them horizontal like I did the first time, but this time it was in the vice that held them steady.
Next biggest problem I had was my own shaky hands, not the best to use when you’re trying to set that needle precisely. Frustrating. When I got it where I wanted it, and I put the voltage on it. It would rise from the pin to just over 40. If you pushed it lower with your finger, it would rise to the same place. But if you pushed it higher with your finger, it would only come down to maybe 44. But it did it consistently. Then I tried it vertical and the needle wouldn’t rise. With the power on it if I pushed it past vertical, it would fall to the high side. Frustrating.
I put it back in the dash with a just a couple screws and I did the test drives past the school radar sign. I was still running 7 mph high. So I took it back out and went through the process again.
Since it was reading pretty consistently 7 MPH over, I applied the 1.5 V, looked where the needle was, popped it off and placed it 7 mph higher (after a half dozen shaky hand episodes). When I pushed it lower with my finger, it would return, and when I push pushed it higher it would come back to about 3 MPH higher. I was out of time because I wanted to see the cute little brunette one more time before I drove up to Carlisle, but I also needed a test drive the truck for other reasons. I was planning on doing the CB calibration now that I have my radio working properly.
So after a quick shower, I headed up the interstate about 7 PM. Due to the bad weather, the traffic was too congested to play CB calibration. However, when I was coming home about 11 PM, the rain had stopped and the road was fairly empty. But when I called out to the rigs next to me, no response. When I called for a radio check, two out of three times somebody would tell me my radio was working. So I tried about 10 times riding down the interstate, but I had no takers. Obviously, they were all simply intimidated by the Road Ranger and didn’t want to play.
So around midnight, and it had started to rain again, I went back-and-forth past the three school radar set ups not too far from home. Two said the speedo was dead on the money at 35 and at 42 mph, and one said I was reading 41 when my speedo read 40. Problem solved, huh Not quite.
When I was radar checking that last little bit, and I was down to less than 1/4 of a tank of gas, the “check gauges” light came on, also a new feature on this cluster, and the gas gauge went to zero. Then the gauge would come up in the light would go off, three times in maybe 20 minutes So when the rain stops this morning, I’m going to pull the cluster one more time and just check all the connections with that sub cluster, and put it back together. Either way, that will be the last thing I do, but now I’m planning on bringing the old cluster with me because I’ve become an expert at opening and closing the dash in about 15 minutes, and I’m going to need the gas gauge more than the speedo if it acts up on the trip.
BTW, side note: when I first got the truck and I went into the dash to replace all the burned out dash lights, I changed all those 7 mm and 8 mm hex heads to Phillips head screws. With a long bit and a short bit on the drill, I can get them all out in a couple minutes. I still kept the 8 mm hex heads on the metal panel behind the lower plastic panel.
But, hey, I’m still happy as a clam, and I really appreciate all the effort you guys put into this. Really. If we fool around with 30-year-old/320,000-mile trucks, we’re going to have bugs. It’s not life and death, it’s a hobby It’s all heading in the right direction and I’m looking forward to the show.
