No Crank after Engine Install
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No Crank after Engine Install
I'm new to posting so forgive me if I'm doing something wrong.
Truck: 1996 Ram 1500 5.2L 5spd
I just rebuilt the engine (high mileage) and threw it back in the truck yesterday, I went to hit the key and nothing happened. Here's the steps I went through while troubleshooting, the battery tested at 12.4, I've bench tested the starter and it works, looking at voltages on the starter posts I'm not getting anything at the switched post when hitting the key, but I have constant power at the other post. I swapped the starter relay with the fuel pump relay and no change. When looking at the voltages getting to the relay I have constant power on one side but no other power when the key is on or off. I've done a bit of research and it seems the neutral safety switch could be the culprit but the previous owner said he "bypassed" it and I thought that was just a automatic thing, so I'm not sure what's going on there. I plugged in my cheap OBD2 reader and it would go through the reading process but then throw an error that it couldn't get any info.
I'm mainly worried I forgot some plug while installing the engine although the starter circuit seems pretty bare bones.
Any help would be greatly appreciated.
Truck: 1996 Ram 1500 5.2L 5spd
I just rebuilt the engine (high mileage) and threw it back in the truck yesterday, I went to hit the key and nothing happened. Here's the steps I went through while troubleshooting, the battery tested at 12.4, I've bench tested the starter and it works, looking at voltages on the starter posts I'm not getting anything at the switched post when hitting the key, but I have constant power at the other post. I swapped the starter relay with the fuel pump relay and no change. When looking at the voltages getting to the relay I have constant power on one side but no other power when the key is on or off. I've done a bit of research and it seems the neutral safety switch could be the culprit but the previous owner said he "bypassed" it and I thought that was just a automatic thing, so I'm not sure what's going on there. I plugged in my cheap OBD2 reader and it would go through the reading process but then throw an error that it couldn't get any info.
I'm mainly worried I forgot some plug while installing the engine although the starter circuit seems pretty bare bones.
Any help would be greatly appreciated.
Record Breaker
Joined: Dec 2018
Posts: 1,075
Likes: 165
Yes the starter circuit is fully "analog" and doesn't rely on the PCM like in newer vehicles. Normally the manual transmission vehicles have a clutch interlock switch at the pedal but that can be jumpered so you can start in gear (typically a Jeep thing). You might want to double check that. The neutral safety switch for automatics is on the other side of the starter relay and closes the ground connection (classic 90s Chrysler wiring....) and manual trucks connect to ground directly. Things to check: Relay pin 85 connects to ground, pin 86 should get power when the key goes to "start", jump relay pins 30 and 87 to confirm the starter load circuit is working (DOUBLE CHECK TRUCK IN NEUTRAL FOR THIS !!!).
Edit: Also make sure you have a proper ground between the engine and the frame.
Edit: Also make sure you have a proper ground between the engine and the frame.
Last edited by DerTruck; Mar 25, 2024 at 11:56 PM.
