99 7.3

[mack82]

I have a 99 f450 that when i turn key on i am getting a buzzing noise from what sounds like to be under the dash. today when i turned the key on it acted like i wouldnt getting full current to everything and it wouldnt start i turned the key off and then back on and it started up fine. I just put a new IDM in the truck and I dont want to damage it. the noise was there before i installede the new IDM. would the switch down on the column make that noise

[mxfever090]

A relay will make a buzzing sound when it's only getting around 9 VDC. If I had to put money on it I would bet you have a bad or corroded batter cable. And most likely one on the starter.

[RichardT]

yup every time mine does that, i had to replace the batteries

[mack82]

i will check the battery cables the batteries are only a few months old

Originally Posted by mxfever090

A relay will make a buzzing sound when it's only getting around 9 VDC. If I had to put money on it I would bet you have a bad or corroded batter cable. And most likely one on the starter.