Ok guys I had to replace my vp44 so I also bought a new airdog 150 lift pump. So my question is. My lift pump wire that comes off the ecm when the key is in the on position it’s only reading 8.9 volts. Will this be enough voltage to trigger my relay for my new lift pump. Or is my ecm bad. Again the key is in the on position not cracking

At initial key on you only get about 1 second of battery voltage to run the pump. If you bump the starter, no engine start, you will get about 20 seconds of battery voltage. So if you are checking power outside of those time frames you should not get battery voltage from the ECM. The only time you have constant power on that lead is while the engine is running.

Edited March 12, 20196 yr by dripley