Hi folks, Mk1 Golf GTI cabriolet 8v 1987. I've got an overheating issue. I've had a read of the coolant FAQ so have a list of things to try out, I want to start with the radiator fan, as this didn't come on whilst limping home tonight. I think i understand how to test it, but need a little help...I can't even disconnect the damn connector! First of all, I'm trying to pull out the electrical plug at the bottom of the rad on the passenger side, just below the battery. It just seems to turn about an 1/8 of a turn either way, I was wondering if its a bit like a light bulb if you know what I mean, turn it as far as it goes one way and it should pop out, turn it the other way to lock it in place ? But I've tried both ways and it won't come out, I don't want it to break obviously. Lets assume I mange to get it out at some point, is this where I bridge the pins? I was thinking maybe the lead that goes directly into the main motor of the fan, the one with one of those squeezy type connectors. Basically I'm a total electrical noob and want to see what's going on with my fan. In the mean time, I'm going to scour the web for car cooling explanations, followed by car electrics for beginers... Thanks in advance Rog
You don't need to remove the sender just pull of the wires... iv'e only just got my golf but believe the wires should just pull off ( will look @ mine later) turn on the ignition and bridge the conectors (on the loom not the sensor) If the fan comes on then it will be the sensor that is faulty and not completing the circuit.. If it does not work then test for power either with a volt meter or you could get away with a bulb and two wires ( although it's a bit fiddly) if there is power then it's more than likely to be the fan motor if there is NO power check the fuse and then wires if neccesary... at the worst case you can run a switch off the dash and opperate the fan from that although it's a bit of a nob.. hope this helps
Thanks for the reply, I can get a multimeter from my neighbour. Checked the fuse and its fine, the only thing I did notice was it had a 10amp instead of a 30? On another site specifically for the cabriolet they've got a diagram of the fuses with their ampage and what fuse do what, I noticed a 30 in the headlamp slot so swapped them over, I know the lights work, so that also proves the 30 amp fuse is good I guess? Meanwhile I'm still trying to unplug the electrical connector at the bottom of the rad to try and force it to work, which will hopefully tell me if the switch is dead or not. I've managed to twist the connector all the way round now but it still isn't budging, lack of space to move doesn't help, but I'm not sure if it should pull out, or even if the whole grey plastic part along with the rubber boot should be removed, or just the rubber boot bit.... This is taken from the cab site (http://www.cabby-info.com/cooling_system.htm) I'm trying to follow... Check the fan thermo switch: Disconnect the thermo switch connector; using a jumper wire, make a connection between terminals (2-speed fans: low speed is red/white wire, high-speed is red/black). If the fan runs, the thermo switch is faulty and needs to be replaced. If the fan fails to operate, check for voltage at the thermo switch connector (red wire). If voltage is not reaching the connector, check fuse #1. If the thermo switch is good and the fuse is good, the thermostat (in the water pump housing) may be faulty. Note: Cabriolets up to (and including) 1989 with A/C do not have two-speed cooling fans; these cars have one-speed fans that are two-stage (fan is turned on when the A/C is turned on). From 1990-1993, Cabriolets were equipped with two-speed fans; those with A/C would then have two-speed, two-stage cooling fans. A/C-equipped cars utilize dual temperature thermo switches. This means that one-speed fans have a 2-wire connector, but still use a 3-prong thermo switch. Thanks again Rog
Just found this on here... http://www.clubgti.com/forum/showthread.php?t=193601&highlight=fan Which I believe is the part I'm trying to remove, and from what I can see here this is the grey bit I'm twisting around, so I should be just pulling out the rubber boot and the bit inside that...
Still can't pull the bloody thing out! I had a look in my Mk2 16v to see if that's a similar setup, which it is, but lots more room to move and with a tug it just came out, the MK1 is a different story though, need tiny hands, probably hasn't been removed in years, if ever...
Right gave the connector a bit of a blast from some WD40 and left it, came back and with a bit more wiggling the thing has come out. Only two contacts, so bridged them and the fan spins. So from what I've read this means the thermo switch is broke? So have I understood this correctly...Due to the fan not kicking in, the water temp rises building the pressure up and then the cap (older black crappy type) starts to spray out the water/anti-freeze? With a new fan/thermo switch the fan will kick in at the required temp, and the pressure shouldn't build to a point of losing water? I guess the sensor is the grey plastic part that bolts directly into the bottom of the rad, where I disconnected the connector, when I remove this I assume the water will come out, so its time to get a new switch... Here's a useful link for how the coolant works, not entirely sure how accurate it is for the Golf, but its helped make things a bit clearer for me. Click the start button and you can see it work as the temp increases. http://auto.howstuffworks.com/cooling-system2.htm Thanks again folks Rog
Typical, none of the local places have a fan switch in stock, so can't get a replacement until Wednesday. Until then would it be reasonable to permanently bridge the switch with thickish piece of wire or paper clip until I get the new switch? This would mean the fan was permanently on whilst the car is running, but this sure means the end of the over heating? But is this a good idea in the mean time? Thanks in advance Rog
This isn't working quite as I expected :/ When I bridged the connector originally to test the fan switch I had the ignition on, therefore I thought it only worked because the car was ready to start, so with the car switched off the fan wouldn't work, well I found something suitable to bridge the connector permanently and the fan kicked in even though the key wasn't even in the ignition! So, if I remove the fuse for the radiator fan, and have the connector bridge will it not work until the fuse is put back in? So I can put the fuse in when I want to use the the car, remember this is only to get me to and from work on Tuesday/Wednesday, work is a 20 minute trip... Rog
I'm going to try the semi-permanent fix, have the fan switch bridged, and pop the fan in before I set off, and remove it once I'm at work. Hopefully I'll be able to pick up the new switch Tuesday or Wednesday... Thanks again Rog
Well I've got it set up so the fans on permanently and the temp is still going almost to the top, temp light didn't flash, was only driving for about 15 mins, and its gone 9, so not exactly hot out there this time of night. I reckon my overheating must be more than just the faulty fan switch. No sign of the reservoir cap spitting any water/anti-freeze this time though. When I got back home, I popped the bonnet to check the res cap, and I could just hear the water bubbling away and hissing quite a lot, thing is, I'm not sure if this is normal, as I don't finish a journey by looking under the bonnet, so this could be fine, I'm thinking not, and more importantly don't want to wreck my engine I think I'll have to ride the push bike tomorrow, order a new switch from somewhere local rather than VW as I won't be able to get to them to pick it up, then when I get home tomorrow I'll follow the coolant FAQ and see if I can identify whether the thermostat isn't working, or the water pump, or maybe the radiator...
A couple more questions... Does the temp light only flash due to lack of water/anti-freeze? I figured it was also a warning that the car was over heating. I've been reading that overheating, due to water loss could be down to a head gasket problem. Are there any simple tell tale signs for a head gasket problem? Thanks again Rog
Right, filled the res back up, ran the car with the cap off, squeezing pipes and hoping to get out any air that may be trapped. Kept an eye on the lower rad hose and this didn't start to get warm until the temp gauge was half way which makes me think the thermostat is working correctly. Top hose gets too hot to touch eventually. Due to the potential head gasket issue I thought I'd keep an eye on the exhaust as it all warmed up to see if I got lots of water coming out or steam, but all I got was possibly very tiny droplets of what might be water. Decided to take the car for another test run, noticed the gauge getting towards the top, so put on the internal heater to help take away some heat, this helped, then after a run along a decent bit of road around 60ish, pulled straight over, wanting to have a look under the bonnet and before I got to completely stop a puff of steam came out the res side of the bonnet and a load of hissing, I'm thinking this isn't good. The red temp light never came on, let the car cool to below half way on the gauge refilled with more water and drove home, took another 5 mins and the temp barely got above half way, also kept the heater on full whilst driving. Before I set out I found a small leak which I think is either coming from the rad or the lower hose that connects to the rad, will jack it up tomorrow and run it so I can confirm, could this be my issue, seems a bit harsh to me, but I'm not the expert obviously. Has anyone got any suggestions as to what I should try next? Riding 15 miles to work is going to kill me before the weeks out Thanks in advance Rog
