FIXED! Howto Inside: Auxillary water pump electrical feed on

[Toad 0]

It appears that I've made an error with my VR.

 

I took it out for a run the other night, and the fuse for the auxillary water pump kept blowing (the pump ran when I stuck a new one in), so for the last few miles I put a 15 amp fuse in, as it was all I had left, and yes I know that was wrong, but I didn't think it would hurt. I got home and the motor was toasted, now I've come to check the wiring and have found that there is no 12v feed to the auxillary pump now when the ignition is on. I've checked the fuse, which is ok, and have fount that there is no power as far as the fuse by running the multimeter from the earth to the fuse itself. The 20 amp fuse next to it gets power fine.

 

Could I have blown a fuse elsewhere in the car? I couldn't see anything blown in the fusebox. Or could I have cooked the relay in the control unit?

 

My next port of call is the connector to the control unit. Does any one have a wiring diagram of this, or know which wire does what?

 

Cheers

 

I'll be feeling sad in the corner now :(

[double-6s 0]

ooh bummer mate :(

 

hope you sort it - you know where to come if ya need any bits! :)

[Toad 0]

Cheers Will.

 

I'll give you a shout if I do find anything....

[Toad 0]

I've been thinking further about this...

 

Does the pump run on for 10 minutes if you just switch the ignition on and off rather than start the engine? If so, I assume that the auxillary pump is controlled by a relay in the cooling relay pack, which is switched on by the ignition and runs for 10 minutes after. So I should be able to find out if the relay is recieving a supply from the ignition. If it is, and there is no power being supplied as far as the fuse, then I can assume that the relay is cooked? If the relay isn't recieving a supply from the ignition, then there will be a fault between the relay and the ignition?

 

I can only assume that the fault will be in the relay, or between the relay and the fuse (Melted connection?).

 

Any thoughts?

 

I'm really annoyed with myself that I didn't just stop and investigate, rather than trying to pootle home....

[bigpants baby 0]

I have a spare pump & aux pump/fan relay box if you need one?

[Toad 0]

I have a spare pump & aux pump/fan relay box if you need one?

 

Cheers. I might PM you, but I think I have a pump and relay box sorted. Will let you know though.

[Goldie 2]

I can drop the Pump in tonight for you Tom, itll be a flying visit though...

[Toad 0]

Cool! When do you want to mocal it up? Friday night? We'd have saturday if things went a little norks up then?

[Goldie 2]

Cool! When do you want to mocal it up? Friday night? We'd have saturday if things went a little norks up then?

 

Mocal is on hold, being the fanny that i am im not happy with the heat exchanger and the hoses so im gonna get a smaller one with braided hoses and stainless connections and then pop it on...

[Toad 0]

Mocal is on hold, being the fanny that i am im not happy with the heat exchanger and the hoses so im gonna get a smaller one with braided hoses and stainless connections and then pop it on...

 

haha. You are a fanny....

 

First dibs on the exchanger and existing hoses then...

 

Do you want to chuck the mount in then anyway?

[Toad 0]

Right...

 

I fixed the problem, and it seems to be fairly common having spoken to other VR owners.

 

When I removed the box, it rattled, so I knew something was up. It turned out that one of the components had unsoldered itself fromt he circuit board, but could be reattached easily.

 

First disconnect the plugs from the relay pack, and test for continuity from the black and red wire which runs from the smaller plug to the positive terminal on the motor. This shows whether the wire is ok. Next test the live feed to the control box, which off the top of my head is the bottom right terminal in the plug as you look at it. This should switch on and off with the ignition.

 

As far as I can work out, the relay pack has a main feed from the battery (One of the large wires) and feeds to the fan speeds (The other 3 wires), A switched 12v supply and connections to all of the thermoswitches, and the auxillary pump through the smaller plug.

 

When I was happy that the fault was inside the relay pack I took it off, and found it rattled. To take it apart, you need to cut the silicon out from the bottom and remove the fuses and screws from the top. When this is done, you should carefully lever the top off of the base using a flat bladed screwdriver and a couple of knives, the lid only clips onto the base.

 

Be carefull taking it apart, as the unsoldered components can fall out at this stage.

 

I found I had a black item (Diode?) which had one leg completely unsoldered from it's hole, and the other leg, and endplate unsoldered from the end of the diode.

 

With a soldering Iron, I removed the spare leg and endplate and resoldered them to the diode, then cleared out the holes in the pcb so that the legs would fit back through (Make sure it fits back in the same way as it came out!) and resoldered them to the back of the PCB. I popped the top on, fuses back in and the auxillary pump worked again.

 

I can't vouch for how how long this fix will last, but it seems to work.