Voytek

For cars with cooling flap control (1987 through 1989 I belive) there is 45 min time delay for auto ON for radiator cooling fans to cover hot spots in cooling system. After John Speak advise, I have waited for 45 min. Sure enough, current did drop to 20 mA. So, all is per Porsche design!! This is complete discussion on this: https://rennlist.com/forums/928-forum/180772-what-is-1987-s4-normal-battery-load-with-ignition-key-out.html

Flott Leben

Voytek,
Thanks for the info. I read your linked thread and this sure seems like the same amount of curent draw as mine. (I don't know why my search didn't pick that thread up!) I will go through the procedure again this weekend and wait 45 minutes and report back to everybody with the results. Thanks for posting!

Flott Leben

Voytek was right on the money. I let the car sit for an hour after turning it off and opening/closing a door and the curent draw was 20 mA - normal. It must be the cooling fan/flaps control remaining charged for 45 minutes. What is a little odd is that if you disconnect the battery and turn the key just to position "I" and then off, it still charges the cooling flap circuit for 45 minutes thereafter. In any case - just thought I would report back with the outcome. On to the next issue . . . Thanks to all for your help.

SharkSkin

Thanks, I'll keep this in mind the next time I help to find a drain on a car with the flaps. During troubleshooting, it's probably easiest to unplug the flap controller, once it has been verified to be operating as expected.

Bill Ball

I found a note about this in one of the technical guides, noting the 45 fan circuit minute drain (will locate again), just as Voytek and John advised. It would be good to find out just what years this affects, as I don't think I have this on my 89 and we didn't observe it on Konstantin's 91 (or was it 90?).

Flott Leben

Voytek e-mailed me this technical diagram:

Bill Ball

Cool. Yeah, I found something that specifically described the 45 minute drain in reference to parasitic drain evaluation. Just like to nail down if it is 87-89 inclusive.

Bill51sdr

Bill, don't look too far ahead model year-wise, I believe Porsche got rid of this system in '91 or '92.

Bill Ball

I know 91 doesn't have it for sure. 89 is a question. It may be 87-88, but one post guessed 89 too.

Alan

Radiator flaps were deleted in 91 if that helps ... seems this is also talking about the fans on thier own as well... so maybe it contiunued longer. My car's fans do run on sometimes when well warmed up - but not for very long 45 mins seems like overkill! ... if it were me I'd just uses a temp switch to supply the thing whil eit was still hot and not maintain a relay delay powered for this... humm.

Alan