Blower motor runs only on settings 2-3
 

Hi everyone, the other day I replaced the heater core in my 84 Camaro Berlinetta. I now have heat and that is what I was going for...(YAY!)haha but here's the deal, I only have heat on setting 2-3. The first and last(1&4) settings do not work at all. I pulled the heater resistor and checked it thoroughly for any damage, it appears to be in "new condition" so I am thinking the problem is something different. What else can I do to get my heater working properly? Could the heater switch be cooked in those settings and if so how can I test it to see?

onthedownlow

Re: Blower motor runs only on settings 2-3
 

Yes the switch could be bad.

Also, high speed uses a relay, with a feed of hard battery instead of all that power passing through the switch.

There is a connector of incredibly STOOOPID design in that battery feed. Specifically, it uses the PLASTIC of the connector, which MELTS when it gets hot, to provide tension on the terminals. So when the connection between the terminals gets a little weak, it heats up; which softens the plastic; which reduces the connector tension; which weakens the connection; which melts the plastic; which loosens the connection even more; which eventually burns the plastic to ash; which completely removes the tension; which kills high speed.

Follow the purple wire from the bolwer motor. A few inches away from the motor it goes into a connector that plugs into a small box. That's the relay. One of the other wires in that same connector is a big fat red one. Follow that wire. It goes across the windshield cowl above the motor. About over the pass side valve cover, you'll come to the STOOOOOPID connector. Cut it off, both ends, and replace it with a set of the BIG HEAVY-DUTY yellow slide terminals; not the little weenie ones that are just like the red ones except with a yellow barrel, but make sure they're the BIG HEAVY-DUTY kind. Insulated preferably. Or, cover them with heat-shrink.

You can test low speed and just make sure that there's 12V reaching the resistor. There are 3 resistors, and 4 wires in the connector to the resistor assembly. One wire goes toward the same relay as described above (you can look at the relay and find the color) and is at the end of the chain of resistors. The wire for 3rd speed goes to the first junction between resistors; the wire for 2nd speed goes to the 2nd junction; and the wire for low speed goes to the opposite end of the chain from the wire going to the relay. The relay when not energized sends the output from the resistor chain to the motor; in high, it's energized, and sends (or doesn't send ...) hard battery to the motor instead.

Re: Blower motor runs only on settings 2-3
 

sofakingdom,


I just wanted to say thanks for answering my question. It makes sense what you said about the relay. I haven't got around to removing the stoopid connector yet but as soon as I am done with my trim work I am gonna get on it. Thanks.
onthedownlow