explosion in dash?

I was driving this morning (45 mph, regular cruising) when what sounded like a gun shot went off in the cab. Sounded like it came from right in front of me. In the dash?? I didnt loose any fluids that i could tell, engine didn't skip a beat. so i kept on driving. Heater and radio still work (newer radio so prolly not a capacitor exploding) what happened?? Could it have been a vacuum hose for the speed control???

Weird!  Did the speedo quit?  Like maybe the cable snapped?  All the gauges work?

I’m just guessing.

Different era, but my 1992 Bronco's dash will pop (not as loud as you described, but loud, and will startle you) when the defrost is on and it warms up or when it's hot out and the A/C cools it down.

I don't know what it is. First time I heard it I thought the glass cracked.

Any chance a rock or some other road debris flew up off the front tire and smacked the floor of the cab?

delco1946 wrote

I didnt loose any fluids that i could tell...

You checked your shorts?

delco1946 wrote

...what happened?? Could it have been a vacuum hose for the speed control???

Not likely - a hose doesn't have enough volume to move the amount of air necessary to be mistaken for a gunshot at a difference of only ~14psi.  I'd be looking at things like the plastic HVAC case, the dash pad backing frame, the cast Aluminum pedal box, and the firewall around it.  It could have been the sheet metal, or the seam sealer.  If there are any soot stains on the engine side of the firewall (indicating an exhaust leak), I'd look inside near them.

grumpin wrote

...my 1992 Bronco's dash will pop (not as loud as you described, but loud, and will startle you) when the defrost is on and it warms up or when it's hot out and the A/C cools it down. I don't know what it is.

Steve83 wrote

delco1946 wrote

I didnt loose any fluids that i could tell...

You checked your shorts?

delco1946 wrote

...what happened?? Could it have been a vacuum hose for the speed control???

Not likely - a hose doesn't have enough volume to move the amount of air necessary to be mistaken for a gunshot at a difference of only ~14psi.  I'd be looking at things like the plastic HVAC case, the dash pad backing frame, the cast Aluminum pedal box, and the firewall around it.  It could have been the sheet metal, or the seam sealer.  If there are any soot stains on the engine side of the firewall (indicating an exhaust leak), I'd look inside near them.

grumpin wrote

...my 1992 Bronco's dash will pop (not as loud as you described, but loud, and will startle you) when the defrost is on and it warms up or when it's hot out and the A/C cools it down. I don't know what it is.

Well cool! Thanks!

Well it was sunny and sort of nice out, so maybe the dash was getting warmer? I’ve only had the vehicle for about a month. I’ll take another look over the  weekends, but so far I haven’t noticed anything. Although knowing my luck something bad happened.  It scared the daylights out of me though, and I’m sure the people driving behind me must’ve thought I was having a seizure .

Let's hope it was just expansion.  But let us know what you find out, please.

forgot to mention, all gauges are still working. The mystery continues...