DD Gauge help

[JamesKrucial]

Can’t figure out check engine light wire , another person installed Dakota digital gauges , truck is an 89 v1500 stock 5.7
Having low rpm stumble tha goes away when temp sensor is unplugged , already replaced sensor+ pigtail as well as verify Fuel pressure 11 psi solid , next was try and pull codes but the light isn’t wired into DD box any help would be appreciated

 

[Bextreme04]

The SES light wire should be a brown/white wire coming from the ECM connector. It will have 0v with key off and then 14v with key on. It should be flashing between 0v to 14v to light the bulb up in order to indicate a fault code with the ALDL pins jumpered.

https://www.gmsquarebody.com/threads/check-engine-light-not-lighting-up.18338/

You mention having this issue with the temp sensor unplugged... you aren't using the factory temp sensor connected to the DD gauges.. right? The temp sensor on a TBI is VERY important and will have fueling all messed up if it isn't correct. You should have the factory temp sensor connected to the TBI ECM and then ONLY use the provided DD temp sensor installed in a different location connected to the gauges. The gauge temp sensor should have no correlation to how the TBI runs.

 

[JamesKrucial]

I am not seeing any volts key on , on the brown/white wire on cluster connector

The factory sensor on intake hasn’t been messed with it should still be reporting back to ecm , for the DD they used a port on the water pump housing so theoretically should be fine

 

[Bextreme04]

I am not seeing any volts key on , on the brown/white wire on cluster connector

The factory sensor on intake hasn’t been messed with it should still be reporting back to ecm , for the DD they used a port on the water pump housing so theoretically should be fine

They used a port on the water pump??? WTF would they do that? That's going to be the coldest spot in the system, since it pulls cold water from the cold side of the radiator and jams it into the front of the engine block. I would have expected them to have replaced the original gauge sender on the drivers side cylinder head.

 

[JamesKrucial]

Agreed ^ I was going to swap those out because the harness goes right across the top of the engine

 

[gmbellew]

For low RPM stumble (just off idle) could also be EGR issues?