aki 0 Posted January 24, 2006 hi my vr6 is poorly again :( seems im fixing somthing every week! anyway on my way home from work after sitting in traffic for 15mins i get to the end of my road and suddenly the lights go dim and theres an almighty sound of fans from under the bonnet then the coolant light starts flashing at me,im guessing ive reached stage 3 of cooling fans! i pull on the drive and it boils over coolant everywhere! ive not got a live feed to the aux pump after tracing the wiring it enters the coolant control module i have continuity btwn the module and pump after removing the module i give it a shake and it rattles surly this cant be correct,does anybody elses rattle? sounds like somthings broken off! ive read that i should have 3 fuses on the module but i haven got them,i belive the fuse for the pump is shared with the horn is this correct? my horn works oooh eerrr i cant find any blown fuses so im guessing i need a new module due to the rattle.but why would my car overheat when it was moving along is the aux pump so important? any suggestions before i buy a new expensive control module cheers andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted January 25, 2006 I think the aux pump is there becuase the cooling system on a VR is almost twice the water capacity of the 4cyl models... Are the fuses under the plastic cover in the module?? Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 25, 2006 The aux water pump is also there to circulate the water after engine switch-off to stop any hot spots hanging around. Quote Share this post Link to post Share on other sites
aki 0 Posted January 26, 2006 hi thanks guys, spent last night looking at my fan control module in a threatening way.............didnt work! but i did manage to crack it open and two diodes have fallen apart ive soldered then back in after testing them for current flow so i know they work must have got hot for some reason over time and melted the solder! but i dont know which way round to refit them as they were rattling around going to give it a go tonight! and see what happens :lol: bet it doesnt work and im off to vw to spend £85 yep the coolant pumps fitted for a reason but im sure it should run all the time the ign is on as well as after switch off to circulate the hot coolant. theres not any fuses under the cover of the module just a very big one of 50 amp for the fan itself inside the module is 4 relays with lots of electrikery that i dont stand a chance of fugureing out :? why did they get hot in the first place.......... any ideas cheers andy Quote Share this post Link to post Share on other sites
aki 0 Posted January 26, 2006 hi been out there tonight,fitted my repaired module,let it run and it got to 100 degrees without any fan or auxiliary pump action :( arse! seemed t pressureise up the coolant quickly too i took the cap off at 90 degrees indicated on the dash and it boiled over a bit i want my car back!! andy Quote Share this post Link to post Share on other sites
mattingg 0 Posted January 28, 2006 Well, If you disonnect the multiconnector you should be able to jump the pins and run the fans in ignition live? This will get you car back if it is the fans that are the issue? Will give you time to figure it out? Quote Share this post Link to post Share on other sites
aki 0 Posted January 29, 2006 hi, thanks for the help. been out there in the daylight and problem solved, the rattly module caused a miss diagnosis by me im guessing my aux pump has siezed causing the diodes to get hot and melt, my actual cooling problem was the thermostat stuck ni the closed position the top hose was getting hot from the bypass for the heater! the rad was cold by the thermoswithc for speeds 1 and 2 the stat is in the bottom hose. no heat to sensor = no fan action. about a month ago my horn fuse blew i thought nothing of it untill now! the aux pump shares the same fuse so that must be when it siezed and melteed the diodes after replacint the fuse my horn returned oooh errr :lol: but because the diodes had dropped out the fuse didnt blow again! so for future refernce if your horn stops working check your aux pump and the fan control module as your diodes may have dropped out! re soldering them back in has saved me £85 for a new one the pump cost £60 needed one anyway so im happy just got to locate a thermostat for a vr6 on a sunday frankly i aint got a chance! thanks guys! andy Quote Share this post Link to post Share on other sites
J-Lynch 0 Posted December 1, 2009 Just stumbled upon this thread of gold dust info whilst looking for an answer to why my aux pump isnt working when its brand new. I thought the same thing that it must be blocked or something. Oh and why my horn mysteriously stopped working at the same time! (He says whilst sat in his living room with the fan control module) I had actually decided earlier to have a butchers at dismantling it as I heard that the copper or solder tracks can burn out leaving aux pump in the lurch. How mine started was actually when the (B***t**d of a) 'rad neck' did its notorious disintegration and then blew off the hose whilst I was hurtling down the A45. It left my car completely covered in coolant! I was instantly left with no aux pump and no horn. A bit strange I thought. Im gonna go check the fuse situation out, put the module back in and see what the score is. Any advice on dismantling the module aki? if it turns out that im in the same boat you were? Any info that anyone else has please feel free to share. Many thanks, James Quote Share this post Link to post Share on other sites
aki 0 Posted December 1, 2009 hi strewth that was a while back!! didnt realise id had my car that long....kepp thinking its time to change but struggle to find anything that will do the same job....audi coupe quattro possibly or alfa gtv or celica gt4 who knows! anyway the control module does come apart its a bit fiddly, you have to remove the sealant stuff with a knife of some sort and carefully pop the plastic cover off the pcb with the electrikery bits attached the doidey capacitor bits that have come unsoldered and fallen out due to getting too hot then just need resoldering back onto the board easy really! i cant remember which way around they go .....i think i guessed (either that or it doesnt matter) anyway if i remember correctly it cured the aux pump problem!! and i havent had any issues since! except that i got the new stat from vw on monday after this incident ,fitted it and that failed too! allbeit 2 years later! im currently using a spurious stat that only allows the coolant to reach 80 deg too low i know but im not taking it all apart again unless i have to!! hope this helps and any more problems feel free to ask as just like most people on here ,there isnt much on my car that i havent taken apart at some point!!! andy Quote Share this post Link to post Share on other sites
aide 0 Posted December 1, 2009 timely, have been looking at this problem on mine. i changed the yellow temp sender and the auxhillary pump last weekend, as i didn't trust the 65 - 70 deg water temps and the pump was making a racket anyway, pump now quiet but still have very low temps, but thermostat only opens at 80 degs according to IR thermometer so its not a low temp one what still doesn't happen is the auxhillary pump and rad fan overrunning for ten mins after ignition off, which i understand is controlled firstly by the yellow sender and then by the fan relays - so am guessing its a diode problem as above, had a quick look/shake tonight but there's no rattle from it iirc the aux pump is used to transmit heat from the exhaust side of the manifold to the heater matrix to prevent hot spots/ head warp now have inspiration to unseal and cut open the unit :) Quote Share this post Link to post Share on other sites
