Heater blower advice

[kkkarpuk]

Since the car is off the road it is time to dig into things that I want to fix. The heater blower in the engine bay has never worked.
I bench tested the blower and it is dead. The fuses show power, I checked power to relay pin 3 and it is there, I checked the power connection to the motor and it is not there, does this mean that the relay is dead as well? I have read many posts on this and I wanted to confirm that I am understanding all this. Before deciding on how to proceed I want to make sure I am checking things correctly. Maybe backdating is the way forward...
Any advice or insight is appreciated

Ken

[DRACO A5OG]

Put a 12volt source to the motor to see if it is not siezed. It may just need to be taken apart and cleaned and lubed.

If you are not to picky about the varibale speed, go with a cheap replacement but the OEM spec motor out host sell works perfectly, just need to splice the wiring.

[86 911 Targa]

Originally Posted by kkkarpuk

Since the car is off the road it is time to dig into things that I want to fix. The heater blower in the engine bay has never worked.
I bench tested the blower and it is dead. The fuses show power, I checked power to relay pin 3 and it is there, I checked the power connection to the motor and it is not there, does this mean that the relay is dead as well? I have read many posts on this and I wanted to confirm that I am understanding all this. Before deciding on how to proceed I want to make sure I am checking things correctly. Maybe backdating is the way forward...
Any advice or insight is appreciated

Ken

Ken,

Here's the CKT:

pm me as needed.

Good luck,

Gerry

[kkkarpuk]

Thanks for the reply Gerry,
I took the motor apart and found this
and this

so that is confirmed as dead.
I'm suffering from a bit of info overload from all the reading. How do I test the relay to know if it needs replacing?
I don't know the difference between years but mine is a'87.

[timmy2]

Time to backdate your heat?

[86 911 Targa]

Originally Posted by kkkarpuk

Thanks for the reply Gerry,
I took the motor apart and found this
and this

so that is confirmed as dead.
I'm suffering from a bit of info overload from all the reading. How do I test the relay to know if it needs replacing?
I don't know the difference between years but mine is a'87.

First, replace the motor, then let's see if you have heat.

Try used parts on this forum, or eBay.

porsche heater fan motor | eBay

Or:

http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=911-624-151-03-PH&catalog_description=Engine%20Compartment%20Heater% 20Blower%20Motor%20%28motor%20only%29%2C%20%39%31% 31%20%28%31%39%37%34%2D%38%33%29%20%28will%20fit%2 0%31%39%38%34%2D%38%39%20if%20plug%20modified%29%2 0

pm me after motor replacement with results.

Gerry

[kkkarpuk]

Thanks Gerry,
I put an add on wanted to buy and have had some responses. Let's see what happens once a new motor is installed.
Thanks again for your input.
Ken

[aj88cab]

Ken,

Per the diagram above from Gerry, pin 3 is power (from fuse into relay) for the foot well blowers. For the engine compartment heater fan you want to check pins 7/8 for power from fuses & pins 5/6 for power out of the relay to the engine blower.

You reference pin 3 in your first post which is for the foot well blower circuit, but if the above pins (7/8, 5/6) checkout, your relay may be OK as far as the heater blower is concerned, whether the relay operates the footwell blowers will not be clear until you get a running engine compartment heater fan.

To check these items, Ignition must be "ON" (second "click"), but engine doesn't need to be running.

Good luck,
Andrew

[kkkarpuk]

Thanks Andrew,
That's the kind of direct info I was looking for. I wondered about having the car running as nothing was working properly. Pulling the relay and testing the connection holes I do have power at 7/8 but pins 5/6 showed nothing. On the relay itself I put power to pin 7/8 and pins 5/6 showed nothing. Before removing the blower and relay I tested the lead connecting the blower and it showed nothing. As the pic shows this motor was never going to respond. One thing I did notice that when the ignition was on and had someone lift the levers between the seats I could hear clicking from the relay in the engine bay. I look forward to getting this done and moving on. I have time, winter is long....

Ken

[aj88cab]

Originally Posted by kkkarpuk

Pulling the relay and testing the connection holes I do have power at 7/8 but pins 5/6 showed nothing.

If this is at the connector with it removed from the controller, this is correct. 7/8 would be 12v from fuse. 5/6 conductors to blower, so no power to be expected at 5/6.

Originally Posted by kkkarpuk

On the relay itself I put power to pin 7/8 and pins 5/6 showed nothing.

If you are testing the controller with the connector removed then this would be expected as there is no power to the relay coil to close the contacts.

Originally Posted by kkkarpuk

Before removing the blower and relay I tested the lead connecting the blower and it showed nothing.

Was the heater lever between the seats up? Did you check the the 12v pin vs. ground pin at the blower connecter? Did you have a complete test circuit to ground? Was ignition in the the ON position? (sorry if these are basic questions, just want to be sure)
Check for continuity on the wires between relay connector (pin 5/6) and 12v pin at blower connector. Also check for a good ground from the ground pin at the blower connector.

Originally Posted by kkkarpuk

One thing I did notice that when the ignition was on and had someone lift the levers between the seats I could hear clicking from the relay in the engine bay.
Ken

If you hear clicking the relay in the controller appears to be operating, whether it is closing properly and completing the circuit is another question. The ground connection from the blower connector mentioned above is critical in this regard also.

[kkkarpuk]

Thanks Andrew,
Everything was as it should be ignition switched on, levers up, grounded tester. I did test the connection from the controller to the blower and showed no power in the yellow lead. I will check the lead connection to ground and go from there, if I can find it.

Ken