Large curret drain, HVAC fan and radiator fan run when key is out. (Page 1/1)
Rsvl-Rider AUG 18, 12:00 AM
I had a problem a few weeks back. See this link for context ...

https://www.fiero.nl/forum/Forum2/HTML/147755.html

That problem was the result of a frayed and separated Fusible Link A wire near the battery. It must have been caused by friction on something until it finally separated resulting in the issue in the linked post. I did not see any evidence of heat or burning of the wire. Once the wire was repaired everything seemed fine. I did not realize there was another problem until the car would not start the next day due to a parasitic battery drain.

This is an odd one...

One issue is that the HVAC fan will run even with the ignition off and the key removed. I can control the fan speed as usual with the HVAC fan speed control. If I press the A/C button on the HVAC control the radiator fan will start running. This would be normal but in this case the ignition is completely off and the key removed.

Another problem I did not notice until after dark is the PONTIAC letters in the tail light assembly are lit even though the ignition is off and the key removed. These are only supposed to light when the key is in the run position.

I have found that the fuse box FAN E terminal (upper right corner of the fuse box) is hot (battery volltage present) even when the ignition is off and the key removed. It should only be hot when the key is in the run position.

I have a 3amp (yes, 3amp) current drain when placing an ammeter in series with the positive battery terminal and positive cable.These current draw problems are eliminated when the FAN E fuse is pulled. Current draw is reduced from 3 amps to 20mA.

So far I have been unable to track down the problem. Any help appreciated!

(edited to add info... 88GT, automatic, factory air, 3.4 swap, daily driver)

[This message has been edited by Rsvl-Rider (edited 08-18-2024).]

Vintage-Nut AUG 18, 11:36 AM

quote
(edited to add info... 88GT, automatic, factory air, 3.4 swap, daily driver)


Thank you...


quote
One issue is that the HVAC fan will run even with the ignition off and the key removed.


The blower relay has TWO power sources; one is "Hot in Run", the other is "Hot At All Times"
I bet that the relay is your problem - I'll check the "Hot At All Times" contactor on the relay to see if it is 'stuck' on. BUT because you have another similar problem, jump to the next issue which is:


quote
Another problem I did not notice until after dark is the PONTIAC letters in the tail light assembly are lit even though the ignition is off and the key removed. These are only supposed to light when the key is in the run position.


You're correct and the "Hot in Run" source is "Fan E Fuse"


quote
I have a 3amp (yes, 3amp) current drain / current draw problems are eliminated when the FAN E fuse is pulled.


If you have power at with FAN E fuse with the ignition is off, my suggestion is start at the source - the key switch

EDIT - On the "Power Distribution" page {8A - 10-0} / Ignition Switch "Run" to "Fan E Fuse" is the Orange Wire
IMHO - I'll start with this wire to check for voltage when the ignition is off....

------------------
Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

[This message has been edited by Vintage-Nut (edited 08-18-2024).]