ExtenZe Overdose

So after doing alot of searching on the forums and testing I am still stumped. My 1980 12A Rx7 heater blower will not work, fuses are good, getting about 14.1 volts from the wire hooked up to the blower and same voltage on both sides of the fuse. I pulled the blower out, hooked it up to another power source and it worked fine. I can turn the **** on all settings and it will not work, so I am thinking maybe its a ground??? I don't think it would be the transistor, speaking of which is the transistor located under the hood behind the driver side strut tower? I also took a look at what I think is a transistor that sits above the blower and all its connections on it (solder) was all intact. I am so stumped at what could be wrong and as soon as I can figure out how to get pics off of my new phone I will post them.

mar3

iTrader: (8)

Never actually had this problem before myself and it's too late at night for me (old man) to pull out one of the manuals to see what might be going on but this problem is very similar in a lot of ways to when I fixed my garage door opener. It stopped working, so I took off the housing, hit the switch and listened. Nothing but a hum for a second and then the lights flashing a sequence. I took the belt off and tried it again. This time, the motor spun freely, so I put the belt back on.

Nothing. It turns out that the motor needed a "starting capacitor" that told it how strong it was, essentially. Once I replaced that part, the garage door opener was fixed....but I have no earthly clue if such a thing is to be found on the 12V chassis of an SA RX-7.

Who thinks they have an answer out there? Time for me to hit the sack!

Mario III

ExtenZe Overdose

Yeah I have no clue whats wrong, about to start ordering parts 1 by 1. Starting at the blower motor and heading back all the way to the battery

Anyone know where the ground is for the switch?

rxtasy3

iTrader: (2)

well the first thing i'd do is check to see if there's power getting to the switch. i've never had this issue so i can't tell u what to do to fix it. and it's not going to have anything to do with the steering column. any grounding of the switch will be in the wiring of the plug to it.

74RX4

iTrader: (10)

No power to switch. Blower motor switch connects the motor to ground to turn it on. Motor has constant 12V when ignition is on. Blue/white wire in blower motor plug should have 12v when Ignition is on. Make sure the black wire in the blower motor switch plug (in dash) has a good connection to ground. There is a ground point on the center console frame, left of stock radio location.

ExtenZe Overdose

So I pull out the switch and it has a good ground. I left it hooked up and was testing the solder points and found out while turning the switch I was not getting any power to the 3 points. So I guess its a bad switch? So I went back to my car to test something and jumped the switch at all 3 solder points with the switch in the correct location. When I did this I heard something like a relay clicking inside my engine bay. Also my blower motor did not crank over on any setting when I jumped the power, just heard a solid 1 click sound when power was jumped.

This is the part in engine bay that is clicking, possible it got wet and shorted inside?

74RX4

iTrader: (10)

Plug G-02 connects to the blower motor switch. This connector has a Black wire which is connected to ground. Blue wire is low power, Blue/red is medium speed 1, Blue/white is Medium speed 2, Blue/green is high speed. If you unplug the connector, turn ignition on and connect a jumper between the Black ground wire and any of the Blue wires the fan should come on at the appropriate speed if the switch is bad.

ExtenZe Overdose

I tryed jumping without the switch and nothing worked, also my wiring is different then what you posted.

74RX4

iTrader: (10)

Sorry, those diagrams are for FBs. SA has different switch, same idea. Not sure exactly what that relay is since I don't have an SA. Wireing diagram appears to show it is the Hot start assist relay A-03. AC Relay B-08, Kick down Relay for AT B-12, EGR relay B-22 are also in that area. Choke Check Relay B-16 is the other relay in your picture.

If grounding the wires in the plug didn't make the motor come on, next thing in the circuit is the resistor. Should be on the air box. Someone with a SA will have to help you with that.

ExtenZe Overdose

Yeah I see it inside and it looks fine, wonder what a bad 1 looks like cause the 1 in my car looks good. I appreciate your help tho

ExtenZe Overdose

So when I plugged in a ground into the ground that laready exsisted on the plug my blower would spin at max speed no matter what posistion the fan switch was turned too. I am novice when it comes to eletrical so does that mean the relay is bad because that is what triggers a ground correct?

rwatson5651

iTrader: (5)

No. The swithch supplies the ground directly. It sounds like you either have a bad switch, or the wire that supplies the ground to the switch is either disconnected or is not grounded properly.

ExtenZe Overdose

Think I found the problem it looked good when I was sitting upside down in my car lol. I said f it and tore out the whole heater assembly which really isn't that hard. Then removed the heater blower resistor and come to find out its burnt out

When I get the part in next week sometime or if I can get lucky and find 1 sooner I will update the thread for future unfortunate people to come across and help them. Thank you all for bearing with my novice ****

ExtenZe Overdose

Drove over to atkins rotary and they had my part, installed the new heater blower resistor and the fan works fine. Thank you all for your help.