|
|
Posted by Sherman in Idaho [72.47.9.37] on Wednesday, December 05, 2012 at 14:11:00 :
This is maybe off-topic because it happened on my Chevy, but thought I'd pass it along anyway. Yesterday I took it up in the mountains as usual with the heater on high. Heater worked fine. Started it up this morning and the heater blower didn't work. Disconnected the wire to the blower motor and measured 2 volts. Not zero, but 2, with the heater switch on. Checked the voltages on the fuse, same deal. 12 on the hot side, 2 on the heater side with the switch off. Zero with the switch on. That's strange. should either be on or off, not somewhere in between. Pulled out the fuse and looked at it. Looked fine. Checked it with an ohm-meter. Just barely shows some conductivity on the megohm range. Looked closer at it and noticed a hairline crack across the fuze element. Could only see it by holding it up to the light. No sign of melting or heating at all. It's a BUSS AGC 10 fuse, red paint band around the glass at one end. Probably the original to the truck, so 45 years old. The last few years I've been driving it about as fast as I can over some pretty rough roads to and from my land once a week or so. I always have the heater blower on high because the low-speed resistor is burned out. I guess the vibration, or vibration while it was warm from having the heater on high, finally got to it with a fatigue crack.
The lesson is don't be too quick to assume a fuse is good because it looks good. Check it with a meter and if you don't have the same voltage on both ends, pull it out, hold it up to the light, and look closer. Or if you're out in the boonies and don't have a meter, just pull it out and look closer.
Follow Ups: