Strangle noise under dash 7.3idi

[AmishAdam]

I recently have become a owner of a 1990 F250 7.3idi. It sat for 14 years and I have been slowing restoring it. I have been stumped on a very strange noise coming from under the driver's side dash. It seems to only happen when the ignition key is on and also while the truck is running. I've felt under the steering column and can't seem to find the culprit.

 

[IDIBRONCO]

Is it some type of hissing (or similar) noise? That would say "vacuum leak" to me. The power brake booster could be a source. If it's old enough to have vacuum controlled cruise, the cruise control cancel switch could be another source. I removed the vacuum line from mine and plugged it off. I gained 1" of vacuum just from doing that.

 

[AmishAdam]

It sounds like a constant clicking sound but really fast. Like a relay.

 

[Brian VT]

Is it coming from the steering column? Maybe the sliding ignition mechanism needs adjusting or cleaning? (not making proper contacts and "sparking"?)

 

[DirtyWood]

When you hear this noise does the voltmeter twitch at all?

 

[AmishAdam]

I did fix the sliding ignition prior. "It had come apart". Voltmeter doesn't seem to budge when the noise is going on. It almost seems like its towards the top of the dash, like right behind the cluster. I wasn't sure if there was something behind the cluster without having to pull it.

 

[AmishAdam]

Turns out the wiper motor was seized and every time I turned the key on the wiper motor was trying to cycle!