KenHen
Junior Member
- Joined
- Nov 12, 2024
- Posts
- 1
- Reaction score
- 1
- Location
- Minnesota
- First Name
- Ken
- Truck Year
- 1978
- Truck Model
- K10
- Engine Size
- 350
In case anyone has had problems with a new blower motor relay...
I was having a problem with getting my blower motor to work, and it blew the fuse when placed in High. After purchasing my second relay with the same results I removed the cap from the relay and snipped out the diode...and then it worked!
The diode is recommended though (called a flyback or freewheeling diode) since it prevents surges and helps the relay last longer.
The problem was it was installed backward (for 1978 K10 at least). Polarity matters apparently so I soldered in a new (1N4007) opposite direction and now the blower works in all settings.
I suppose you could also swap out the black (ground) and the orange (High signal) wire on the plug for the same effect.
As usual I discovered this issue only after replacing the switch, resistors, blower motor and about 10 20A fuses.
I hope this helps someone with the same issue.
I was having a problem with getting my blower motor to work, and it blew the fuse when placed in High. After purchasing my second relay with the same results I removed the cap from the relay and snipped out the diode...and then it worked!
The diode is recommended though (called a flyback or freewheeling diode) since it prevents surges and helps the relay last longer.
The problem was it was installed backward (for 1978 K10 at least). Polarity matters apparently so I soldered in a new (1N4007) opposite direction and now the blower works in all settings.
I suppose you could also swap out the black (ground) and the orange (High signal) wire on the plug for the same effect.
As usual I discovered this issue only after replacing the switch, resistors, blower motor and about 10 20A fuses.
I hope this helps someone with the same issue.
