Hi, I have a 1997 Ford F350, just installed two new batterys and on start up the battery gauge pegs real low and when started it fluctuates from about a 1/4 to 1/2 for about a min, then it stays at about 3/4. Is this normal? it doesnt seem to have any problem starting.

 

THat is from the glow plugs , & its normal ...

 

Yes. It's the glow plug relay kicking on and off, not good for the relay but it is normal.
I turn my headlights on and hvac fan on high to cause electrical draw till the GPR shuts off.

The PCM is set to have the relay on up till 14.1 or 14.2 volts, once the charging system reaches that it shuts the GPR off to prevent over-voltage to the GPR. Then, the volts drops and it kicks the GPR on, then the volts rise and shuts it off, then the volts drop and kicks it on......and so on...

Edit:
Seems to be common on '97. Both my '97 do that, but my '95 and '96 do not.
??

 

Alright thanks for the info!

 

Read this thread, it might answer your question, eventually....

https://www.ford-trucks.com/forums/1...warning-3.html