I want to wire up the fast glow plug relay in my 1985 golf so when I turn the key my glow plugs cycle through like they would on a stock idi diesel vw. The issue I am having is I have found 2 different diagrams, the fast and the slow glowplug relay pin-outs. It looks as if the slow relay has the same pins BUT has a different circuit flow. If someone can give me a positive answer on what the leads should be for input and output on the fats glow plug relay please let me know. Also confirmation that the fast and slow relays are in fact different in internal wiring.
Anways here are the links to the 2 diagrams.
http://www.4crawler.com/Diesel/GlowPlug.shtmlhttp://www.vwdiesel.net/forum/index.php?topic=27695.0
i can't give you a highly technical answer like it looks like you're searching for, but on my 81 rabbit when i bought it, it had the slow system a few glow plugs burnt out and were near impossible to find, so i just bought 4 fast glow plugs and a fast relay and swapped everything out, so everything is interchangeable, hopefully that helps you.
This is a good and bad news, as this means that one of the 2 diagrams are wrong....
Through a series of trial and error I was able to set up a test bench for my glow plug relay. In the process of doing so I think I burnt out the part of the relay that lights up the glow plugs. I found out the link to
http://www.4crawler.com/Diesel/GlowPlug.shtml has the correct information as well as hints of how to set the test bench up. I ended up using the old electronics kit I had as a little kid for the potentiometer which acted as the temperature sensor input, 1 led for the glowplug light and another to check the voltage out to the simulated glowplugs and added 2 switches to simulate the key-on position and starting. So yes to sum this its fairly easy to test the glow plug relay and the schematic from vince was wrong

edit: I was wrong about burning out my relay, the led simulating the glowplug light must be wired with (+) then to the relay .
I don't see what the difference is between the 2 diagrams... other than that the relay needs to be on a hot in run AND start circuit, instead of a hot in run only, or else it will cycle again after the starter stops, which is the same circuit that the injection pump solenoid needs to be on. Also, I have noticed that the relay will not work properly if it's not getting around a full 12 volts.
I should have been more specific originally lol. The key-on switch goes to pin 86 on the relay which on the fuse box is the same circuit as the injection pump stop solenoid. I should retract my earlier statement of Vince being wrong, I was referring to the injection pump solenoid reference on the diagram, which if I had read the entire post originally he goes on to say was misleading.