rite, so ive finally got fed up with the annoying flashy red coolant level light on my cluster which has been there since i swapped the engine. Have swapped the expansion tank and cap for a new VAG one with blue cap to no avail (looks nice and new tho and tried another set of clocks, which did the same thing. Only thing now is i must've made a mistake in the wiring- i had one or two connectors on the engine loom left over that i couldnt work out what they did due to slightly different designs of connectors in the 1990 spec car and 1995 spec engine+loom. been trying to get my head round the wiring, and wanted to check if this is right. cluster: pin T28/02 to fusebox pin U2/05 to fusebox C/08 to Coolant level sensor + Coolant level sensor - to fusebox C/05 to ground so if the circuit is shorted to ground the light doesnt flash if the circuit is opened due to coolant dropping below the contacts in the exp. tank the light flashes. Oddly I have a relay number 42 in position 5, which looking at the fusebox faq should be where a number 43 relay (coolant level control unit) goes. Dont make any difference if i take this out so not sure what that relay does? Any idea what colour/type the connectors on the engine loom that go to the coolant level sensor would be? fanks in advance
I found that I didn't need a control unit. My thread here C5, C8 were right for my CE2 F/B. Mine were shorted by a link on the back of the fusebox, from the factory, so I can't help with wiring colours into the bay. Edit: Except... from a pdf wiring diagram I just found for '91 Golf, I can tell you that the wire from C5 (gnd) is Brown/Red and the one from C8 is Blue/Red. HTH.
hehe cheers pete, been reading your thread already thats where i got most of my info from very useful stuff in there yea i doubt i need the control unit either, just not sure what the number 42 relay is meant to do? i swapped the fuse boxes over when i did the swap as the new one had some breakout boxes on top that i needed for the immobiliser and lamdba probe relay, im pretty sure the 42 relay came from the new fusebox though as it has a 191 part number ie mk3 golf, which came after my 1990 passat. I popped over to my garage earlier to look at the old fusebox and spare relays and i cant find a 43 or another 42 from the old bits so dont think there was one there in the first place.
1st thing, bridge the pins on the level sensder, if that stops it you know its the sender in the tank. next step, disconnect the plug for the dash temp sensor, if THAT stops it the sensor is probably at fault. if the relay wasnt there on your old fusebox and you still have the original dash cluster, then you dont need it. C/5 & C/8 run to the level sensor, it doesnt matter which way the wires are as its just a switch that closes when the level is right. G2/3 goes to the coolant temp sensor, U2/5 is the level sensor wire to cluster (linked to C/8) U2/9 is the dash temp sensor wire to cluster (linked to G2/3) Oh and C/5 is earthed internally in the fusebox. Edit: from a couple Passat diagrams I found this: U2/5 - red/wht - dash pin 2 U2/9 - red/yel - dash pin 23 The diagrams also say the earth for the sensor doesnt run to the fusebox at all, it is earthed elsewhere...
cool cheers for that jonny. was what i thought it was then, all those numbers can be a bit confusing. so to confirm, if i short pins c/8 and c/5 the light should go out? this will let me check the cluster side of things. o and my clsuter loom is a late mk4 passat one and every single wire is white very helpful for diagnostics! im using the clocks out of the donor car as they had electronic speedo and digital tacho (old clocks were analogue and the speedo needle damping magnets were screwed so the needle bounced all over the place ) so looks like i need the relay in place.
ah yes probably! what year is that cluster from and I can check me diagrams to see if it says anything about it
right, I'll get on the case. I was going on the assumption you kept the old clocks! hopefully the US diagrams cver the clocks you have. I already tried elsawin but it has sod all for passats till after 97
yea after realising that B3 and B4 passats are much more similar than i thought I transferred as many bits as I could over, even changed the ignition housing so i could use the chipped key with the oem transponder to start the car. Even the subframe and front cross member/rad support swapped over fine so i could use the huge ABF radiator. i think my car is about a B3.5 now hehe BTW john if we're ever at the same show I owe you a pint!
also, ive just got the relay out the car and it has the following numbers on the bottom: 15, 31, S, G i assume they relate to current paths inside the fusebox?
The pinout for socket #5 is: 1 - ign live - relay pin 15 2 - C/6 - relay pin S 3 - G2/3 & U2/9 - relay pin G 4 - earth - relay pin 31 The US diagrams give me no clues, they dont use the relay either Edit: Aha, found a Golf Rallye diagram showing the relay, tis wired up like so: C/6 - blue/red - level sensor (pin 2 of level sensor socket) C/5 - brn/red - level sensor (earth) G2/3 - temp sensor U2/9 - dash temp
John, youre an absolute legend, thanks so much for that! ahhhhh that explains why it flashes, pin C/8 isnt used if relay 42 is needed, it uses C/6 and C/5 instead. Ive left the original coolant loom in place (coolant level sender and rad thermo switch/fan loom) as i assumed it would be the same on both cars- evidently i was wrong. So the level sender is currently plugged into C/8 but needs to be in C/6. fingers crossed that should work when i drop teh fusebox! I take it that G2/3 goes to the cluster temperature guage (1 pin on side of head) and U2/9 goes to pin T28/23 on the cluster plug.
Yeah I assume thats what the problem is, slight missmatch of loom pins Yeah G2/3 goes to the sensor itself on the head, and I'm pretty sure U2/9 goes to that pin but I dont have a wiring diagram that specifically matches the cluster in your car. However I assume your dash temp gauge works fine so it must be right!
yep the dash temp guage works fine, as does all the MFA etc . . . apart from the MFA outside temp sensor, as with the PB engine it was integrated into the engine loom (pin G2/2), so i took it out, and i cant work out what pin it needs to go to with the ABF loom in place, as this pin seems to be used by something else. ran out of time to get the sensor and associated wiring out of the B4.
hmm not heard of G2/2 being used for anything but the outside temp sensor, its linked internally to U1/2 which then links to the dash. The US passat diagrams agree, but then we all know what use they were for the level relay edit: oops sorry small transistor board in a relay casing edit2: oops again 888 timer chip and a couple of capacitors on a little PCB, in a relay casing
