924Board.org

[Rabbit83]

Hello all,

I'm trying to undo the damage a previous owner of my 924 has done with multiple electrical issues.
At some point the radiatro fan and the fuel pump were put on toggle switches mounted in the console. Right now I am trying to undo and properly repair the fan wiring.

The Haynes manual shows a relay for the radiator fan, but nothing I have found here or online shows a location of the relay. There is an empty relay connector next to the rear defrost relay that has 4 pins in it and 2 have 30 and 15 power as shows in the diagram. The relay is labeled J26 with fuse S18.

The pins in the realy harness do not correspond to the usual 4 pin radiator fan relay and are set up more for a 5 pin set up minus 1 pin but it maybe hanging around up in the dash somewhere.

I'm really at a loss here. Help with the location of the relay and the wiring at the back of the relay carrier would be greatly appreciated!
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1977 Porsche 924
1987.5 Audi Coupe GT Special Build
1992 Passat Wagon

[924RACR]

Correct, IIRC the rad fan relay would be one of the extra relays tacked onto the top of the fuel/relay panel... so it could've been popped off the block at some point.

Sounds like you've located one potential relay socket; do the wire colors match up with the wiring diagram (for the '77)? That'll be the best indicator.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Rabbit83]

Thats part of the problem 924RACR, in the wiring diagram the relay is shown at the top but does not show the wiring colors at the relay.

I am guessing by what it shows that it would have a fuse on top of it like the fuel pump relay and rear defrost relays, but I cant be sure.

I did some checking last night after posting and there is power at the resistor. This is the first component after the relay so either the realy is there and I'm not just seeing it or theres another wiring hack by the PO.

I measured resistance over the resistor it was up around 15 mega ohms, needless to say I have a new one on order along with a thermoswitch for good measure!
_________________
1977 Porsche 924
1987.5 Audi Coupe GT Special Build
1992 Passat Wagon

[924RACR]

Ah. That would be because you have a poor black/white copy of the wiring diagram.

Try this (from the Tech section page http://www.924.org/techsection/elect_diag.htm):


Note that this page explains how to read the wiring diagrams using the fan circuit as an example. This excerpt shows the fan motor and relay... so you should have red, black, yellow/black stripe, red/white stripe, and green/black stripe wires going to the relay plug.

I don't remember if the fuse is supposed to be on the relay, not to sure that it is...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Rabbit83]

Looks like what was tripping me up was the picture of the relay locations in the Haynes manual. I found the correct fuse and relay locations (for my early 77) here:

http://jenniferandjon.com/ABRacing/index.php?option=com_content&task=view&id=16&Itemid=51


I need to keep in mind that the majority of the info out there seems to be for the later 924 and 931, my early car has many differences!
_________________
1977 Porsche 924
1987.5 Audi Coupe GT Special Build
1992 Passat Wagon