Truck has been dead for 5 days A mechanic did some troubleshooting and told me the transfer pump is only getting 7 volts, any ideas????????????

 

Where do you get 7V? at the pump or at the relay?

Do you have 12V into the relay and only 7 out? Change the relay.

What is your battery at and what do you get into the rest of the fuses? Should be 13V or so at the batteries and 12 or more to the fuses.

Cya

 

The batteries and the alt. were just replaced last week and are putting out 13.75v. The relay seems to be the problem, cause thats were the voltage drop is. Is this relay a common problem.

 

If I remember correctly you will have low voltage in the prestart mode. Is he checking it with the engine running?

 

By "bumping" the starter you should have a full 12v at the pump. Like stated change the relay (cheap fix) and check the wiring to the LP and/or fuses.

 

His is a third gen. Might not be the same (most likely is not the same) as 2nd gens. Besides, the 2nd gens do not give full power to the LP unless the engine is running, so on starter bump the LP will not get full 12V I think. ECM will limit the voltage it gets to improve starting.