93 blazer issue

[stickmn78]

Hello, I'm fairly new to dinking around with trucks but decided to jump in. I have a 93 full size Blazer and its kicking my butt. Bought it from a kid who abused the hell out it and just had to put in a reman motor. Everything was wired up right and i am having issues with the electrical system. Basically, the truck runs decent without the gauge cluster installed, and runs like crap with it plugged in. It does not have any issues if you pull the cluster, but when its plugged in, it throws a short to the distributor and the ignition. Any help is greatly appreciated.

 

[ilikemud]

Ran without this issue before the motor swap? Check all your grounds motor to frame frame to body ect... Also look for pinched wires if your 5 volt reference gets screwy to the computer from a back feeding sensor wire it can cause all sorts of issues. Also try isolating circuits plug in the cluster but disconnect the oil pressure sensor from the motor. See if it makes a difference. If not move on to the alternator, coolant temp sensor ect. Things that are connected to the gague cluster hope something here helps good luck

 

[ktmoutfront]

Take the gauges out of the cluster. Plug the cluster in. If this courses the running issue, it's a ground or shorted main power. If not, plug each gauge in individually to find the culprit.

 

[stickmn78]

i had this problem before engine swap. i have pulled the wire harness out of blazer and run a few test with cluster plugged in and not plugged. Plugged in shorts the gauge fuse and green and also the pink wire to ignition. I pulled each one of the stepper motors on cluster and plugged them in one at a time. No matter what order i put them them back in, they start to show short on ohm meter, getting worse with each one being plugged in. I have tried this with 4 different cluster, 2 with tach and 2 without. same problem.

 

[ilikemud]

Trying different clusters especially 4 with the same results would lead one to believe the problem isn't in the cluster itself. Getting a wiring diagram would be beneficial. Will Help to isolate what other things are on that same circuit. If you had the harness out did you check the firewall pass through connector for bend or badly corroded pins? If it was beat on by the previous owner, I have seen pass through connectors solid green with. Corrosion from deep water passings or a windshield leak...

 

[stickmn78]

i unwrapped the harness and checked every wire. no issues that i could see. Thinking of running another wire to distributor that does not come from cluster so there is no short. i pulled wire diagram from Mitchell and there are quite a few components all linked together. One power wire split into 6 different directions. 3 go to the cluster, the rest to the convenience center and then firewall to distributor. Real pain in the ass trying to isolate which one is causing problem. Also got a gray wire that splits off in 4 directions giving me hell.