Just because a fuse looks ok doesn't mean it is.

Joined
Apr 27, 2010
Messages
18,193
Location
Suburban Washington DC
I noticed the under dash fuse box on one of my cars was wet, probably from condensation forming on the inside of the windshield and then dripping down on to it. I pulled out all the fuses and cleaned their tips which were pretty crusty. Just to be certain they are OK, I also ohm'd them. Found five that showed open even though visually they looked fine. If i had put them back I could have been chasing faults that didn't exist except for a bad fuse. I'm guess water may have entered the fuse and frozen, expanding them internally.

IMG_3117.JPG
 
I think that's why you test them quickly for power in the box without removing them. Probe both sides of the fuse where the prongs protrude through the top of the fuse. I never visual check until they show failure, then it's just for an assurance.
 
I'd be concerned if I pulled 5 blown fuses out of my car. Does this car not run? How did you not notice 5 inop circuits?
 
Sitting since 2015 and last ran 2 years ago but wouldn't start since then. Wouldn't even crank. Scanner couldn't even communicate and I found no power at the OBD2 socket. When I checked the fuse box I noticed it was damp. Checked OBD2 fuse and it had some corrosion so cleaned it up and now it cranked but still wouldn't start. Found the fuel pump seized. Replaced that and it started fine but had dash lights for the airbag and no lights for the hybrid system among others so I pulled all the fuses to clean them and when I tested them, five were bad even though they looked fine.
 
Ive had to polish the glass fuse claspers with 400 grit sanpaper wrapped around a bent q tip head wetted with deoxit d5, to get one circuit to work again.
Couldnt believe removing and reinserting the fuse over and over didn't work to break through.
 
Ive had to polish the glass fuse claspers with 400 grit sanpaper wrapped around a bent q tip head wetted with deoxit d5, to get one circuit to work again.
Couldnt believe removing and reinserting the fuse over and over didn't work to break through.
At least the days of chasing fusible links is past
 
I noticed the under dash fuse box on one of my cars was wet, probably from condensation forming on the inside of the windshield and then dripping down on to it. I pulled out all the fuses and cleaned their tips which were pretty crusty. Just to be certain they are OK, I also ohm'd them. Found five that showed open even though visually they looked fine. If i had put them back I could have been chasing faults that didn't exist except for a bad fuse. I'm guess water may have entered the fuse and frozen, expanding them internally.

View attachment 87940
I lost my 98 f150 do to a bad windshield.. water got into fuse box/gem module if this happens when you turn the key you're basically soldering the board.
 
It’s even more fun when you find the fuse box lips lost their tension and full contact begins to fade. I’ve seen two of mine that got so hot that all you need to do is feel around the tops until you get branded . On my old Toyota Celica I found it by just looking under the dash in the dark. The little orange glow said it all. Of course once the holder gets hot enough the plastic deforms and just makes the issue worse. So much for progress, I miss the old style tubular fuses.
 
Sitting since 2015 and last ran 2 years ago but wouldn't start since then. Wouldn't even crank. Scanner couldn't even communicate and I found no power at the OBD2 socket. When I checked the fuse box I noticed it was damp. Checked OBD2 fuse and it had some corrosion so cleaned it up and now it cranked but still wouldn't start. Found the fuel pump seized. Replaced that and it started fine but had dash lights for the airbag and no lights for the hybrid system among others so I pulled all the fuses to clean them and when I tested them, five were bad even though they looked fine.
Is that why you need so many trailers when you move?
 
Back
Top