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Guys, the project is moving along nicely! Finally got the freshly rebuilt 351 fired up, and that was awesome. We now moved on to hooking stuff back up. My son (his truck) didn’t like/want the green cluster lights so he took them apart and scraped the green film off so he could put in blue LED lights. Now once reinstalled none of the gauges work. I tried pulling apart and gluing the pins back on their respective post. Only thing that moved was oil pressure which just immediately pegged to the high side. Fuses are good. Plugs on back of cluster are in correctly. Not sure where to look. I checked all of the grounds (thanks subford for the pics) and they’re good. The only thing that is standing out is I don’t have the fenders or core support completely bolted down. Fenders are just resting in place. Could that be causing a bad ground?? Not sure otherwise if taking the cluster apart ruined them?? . Thoughts?? Contemplating putting pillar gauges in but would rather get originals working. Original
How far did he break down the cluster? Did he just take off the clear plexi, the black surround, then remove the needles and face? Or did he pull the gauge motors. Out of the back of the cluster?
There are a few things that can cause something like this. What I think you have going on is the that you didn't reset the motors to start positions before putting the needles back on. Basically what you will have to do is take the cluster back out and remove the Plexiglas cover and the black spacer. Then remove the needles. I use two spoons. Sounds dumb but works amazingly and won't bend your posts. Just put the tip of the spoons under the center of the needle. Rounded side of the spoon towards the faces. And just push the handles towards the face. They pop right off.
Once off, very gingerly grab a post between to fingers and lightly turn counter clockwise. Like your turning a combination lock. You should feel just a bit of resistance after a second. That is the start position of the gauge. Once you fee that. Let go and without moving the cluster around put the needle back on, wit it pointing to the "low" spot on the gauge face. The do the same for the others. The fact that your one gauge pegged out and your speedo is way off pretty much tells me this is what is going on.
The next thing to try is what you were talking about which is grounds. If the motor doesn't have a good ground the sensors won't work properly and wont send correct info. If the entire dash got pulled out and a ground wasn't re-attached this could also cause fluky gauges.but they should still kinda read something. Double check that the grounds in the clips that go on the back of the cluster didn't come loose from the clip and isn't making good contact.
Next up is the clips might not be seating right. The back of the cluster clips just suck. The suck to take off. They suck to get back in right. If one side of the clip doesn't lock in 100% it will cant the clip just enough to throw things off. Bot sides of the clip have to lock in at the same time or else one side or the other won't lock in.
That's what I've got. Good luck. Let us know what it was.
How far did he break down the cluster? Did he just take off the clear plexi, the black surround, then remove the needles and face? Or did he pull the gauge motors. Out of the back of the cluster?
There are a few things that can cause something like this. What I think you have going on is the that you didn't reset the motors to start positions before putting the needles back on. Basically what you will have to do is take the cluster back out and remove the Plexiglas cover and the black spacer. Then remove the needles. I use two spoons. Sounds dumb but works amazingly and won't bend your posts. Just put the tip of the spoons under the center of the needle. Rounded side of the spoon towards the faces. And just push the handles towards the face. They pop right off.
Once off, very gingerly grab a post between to fingers and lightly turn counter clockwise. Like your turning a combination lock. You should feel just a bit of resistance after a second. That is the start position of the gauge. Once you fee that. Let go and without moving the cluster around put the needle back on, wit it pointing to the "low" spot on the gauge face. The do the same for the others. The fact that your one gauge pegged out and your speedo is way off pretty much tells me this is what is going on.
The next thing to try is what you were talking about which is grounds. If the motor doesn't have a good ground the sensors won't work properly and wont send correct info. If the entire dash got pulled out and a ground wasn't re-attached this could also cause fluky gauges.but they should still kinda read something. Double check that the grounds in the clips that go on the back of the cluster didn't come loose from the clip and isn't making good contact.
Next up is the clips might not be seating right. The back of the cluster clips just suck. The suck to take off. They suck to get back in right. If one side of the clip doesn't lock in 100% it will cant the clip just enough to throw things off. Bot sides of the clip have to lock in at the same time or else one side or the other won't lock in.
That's what I've got. Good luck. Let us know what it was.
it was my sons project. In the learning process he did remove some but not all of the gauge motors…….
