90toytruck

I could use some input from everyone. I have a 90 Toyota pickup 4x4 that I just finished swapping in the GM alternator. I followed the instructions per the instructions at

http://www.frontrange4x4.com/forums/...rnator-Upgrade

And

http://www.rocketcityrockcrawlers.co...%20Project.pdf

Everything worked great, except for now I have no power at the heater blower motor. I can hear the relay clicking, even replaced it with a new one. I have checked the fuses and they are good (the 30a, 10a, and the ign 7.5a under the kick panel. I also checked the resistor and it is fine, I don't have fan on any speeds so I don't think it is that. I have read the white wire into the relay should be constant hot, it is not.

I only used the yellow off the oem alternator harness per the instructions, and changed the fuse box wiring under the hood like it said. Could I have disconnected the power to the heater blower somehow? Everything else works, headlights, dash lights, wipers, and the truck runs great.

Any ideas would be great. Thanks!

scope103

Yes, the white wire to the #5 terminal of the heater relay is "always on." The schematic shows it going directly back to the 80A alt fuse. I don't know anything about the instructions you followed, but it looks like they call for wiring at JB2 (where the 80a fuse is). So I would look for a white wire that is no longer adequately connected.

Good luck!

90toytruck

Thanks, yes the old alternator charge wire was terminated at the alternator. It is still hot because the new 4ga charging wire ties into the fuse box and provides power back through the old alternator wire like the instructions say to do. Does anyone know where the heater wire ties into the 80a fuse wire? It seems to me it has become disconnected from the old alternator wire? Very frustrating...

90toytruck

Just wanted to follow up on this. There are two wires in the oem alternator charge wire harness. One wire goes directly to the 80a fuse in the fuse box, the other is a white with blue stripe and IS the power to the heater blower. I had cut off the oem alternator coupler which disconnected the blower power from the old alternator wire. Connected them together and it now works fine!