I hate brand new bad parts. (Not MC specific)

[Flyinfool]

I was working on the truck installing a new set of LED DRLs. Then it all hit the fan.

 

 

While I was messing around under the hood in the fuse panel I noticed that there was a 10A fuse that was broken, a big chunk missing out of it, It was fuse 48 for the HVAC, It still tested good and everything still worked, but I can not survive nowing I have a broken fuse. So I pulled that fuse and put in the spare fuse that was in the cover for the inside fuse panel. Tested both sides of the new fuse with the test light and it showed as good. The next day I noticed that the compass in the DIC was showing as "--" instead of a compas direction. Hmmmmmm........ So back to my service manual and there is a test procedure for when the compass reads --. So I start running thru the procedure. Step one check the fuse, what do ya know, it is fuse 48 for the HVAC that powers the compass module, the brand new fuse again checked out good as I would expect it to. Step 2 drop the headliner.............. DANG. The compass module is glued to the headliner just behind the drivers head. I was able to loosen things up on the whole drivers side of the headliner to pull it down enough to get my arms in there to get at the module. and test the pins at the connector, my test showed there was no +12V on the pink wire at the module, so I started to follow that pink wire back, it went to a connector under the dash, (I am an old grey fat man, I do not do under dash well anymore) there was no +12V to the pink wire under there either. the next stop for the pink wire is fuse 48 under the hood. So I pulled the fuse and checked continuity of the pink wire from the fuse terminal to the module connector and had good continuity. Hmmmm........................ so just for giggles I stuck the test light probe into the pink wire side of the fuse socket and connected the probes ground clip to +12v. Turned on the ignition and the compass was working again. More head scratching. OK time for more giggles, I put in the old fuse, that has a big chunk missing out of it, back in. Compass is working. I put in the brand new fuse and compass no worky. OK so I have a brand new 10A fuse that tests as good with an ohm meter, looks like good element not broken, will test as good by probing the 2 probe points on the top of the fuse, but will not pass power. I bought some new fuses and installed one at fuse 48 and put another new one in the spare fuse holder for someday, and all is good, then I got to put the headliner back up. I wasted a whole day over a brand new bad fuse that tests good. But then I was home with all my tools and test gear available, It could have got ugly if I were on the road and that broken fuse finally failed and I would have put in the new spare fuse and nothing sill would have worked.

 

I really hate brand new parts that are bad, cuz you tend to go right past them looking for some other problem. How many times on this site have you seen me tell people it is possible to have new bad parts. But yet I still get burned by it. ANd I know better............................ :bang head: :bang head: :bang head:

[mraf]

I read somewhere to beware of the old style glass fuses that are made in China. Seems some of them would not blow thereby frying whatever they were running.

[Flyinfool]

These are modern ATM fuses. I always buy Little Fuse or Bussman brand, more expensive but made in USA, and they blow when they should.

 

ANY style of cheap Chinese fuses have been known to not blow when they should. I have seen Chinese fuses melt into a blob and melt the fuse holder, but still not blow.

[uncledj]

I feel ya.

Rewiring a big industrial HVAC unit, had 3...count 'em 3....bad relays new in the box, picked up at a supplier that morning.

After I figured out it wasn't my wiring, but rather the new relays, I took them apart and there was a white chalky substance on the contacts.

Put an old relay in and was good to go.

Took the bad ones back to the supplier to make them aware of the situation.

I think they were Mars relays, made in Mexico.

[Yammer Dan]

I AGREE:bang head::bang head::bang head::bang head:

[rbig1]

maybe you should check that fuse one more time it could be a left hand one and you tried to use it right handed

[Flyinfool]

These are the fuses that gave me fits, The melted fuse on the right is the one that works just fine, the brand new fuse on the left is the one that tests good but does not work in the truck.

[CaseyJ955]

I read somewhere to beware of the old style glass fuses that are made in China. Seems some of them would not blow thereby frying whatever they were running.

 

It's good to be careful of anything made in China, and by be careful I mean skip it altogether. OEM stuff is expensive but it's worth it, even for a cheap bastard like myself. I have almost completely eliminated this problem by being very careful where items that I buy are made. Unfortunately there are a lot of counterfeit items out of China, designed to look like OEM and in OEM packaging.