[kcastle]

When I hook up the batteries to a 90 IDI, there is a buzzing noize like a glow plug relay or vacume pump. It clicks off and on a few times like it comes up to temperature and pressure, then shuts off. It will repeat this at random it seams. No key is in the ignition, and the ignition is in the off position. Any ideas?

 

[tim94f250]

Is this noise coming from under the hood, or under the dash?

 

[agnem]

The vacuum pump is mechanically driven, so it's not that, and the glow plug relay clicks, but that is all. Did somebody put an electric fuel pump on this truck, or is the heater fan on?

 

[kcastle]

The noise is coming from under the hood. I have not seen an electric fuel pump.