53 replies to this topic

[pete l]

Replace the battery in your digital volt meter. I have one that gives out high readings when the battery needs replacing.

[M700FGT]

Thanks guys - New batteries and we are now reading a stable 12.63!

 

Its a rubbish meter, but I haven't needed to use it before 

 

Fan relay removed and marked up.

 

Looks like neither of the two yellow relays on the left control my horn. Removed both and the horn still works?

 

I did however find a connector plug tucked away under the expansion tank that I had not seen before? This might be for the headlights as I know the previous owner disconnected the dimmer system as there was a motor fault? 

 

So I took one of the other relays and put it in the fan relay location - no change. I had previously checked the relays with a 9v battery. 

 

All 3 relay terminals cleaned and all other electrical systems the car work (Except the headlight dimmer)

 

yes the temp gauge is working. Would be interesting to know when the coolest fan kicks in on other MPI's as my previous mini was a 93 Carb. 

 

Thanks again for all the help. 

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Edited by M700FGT, 21 June 2018 - 04:48 PM.

[Wiggy]

That spare connector is for the AC system on Japanese Minis, I believe.

So to summarise:

With the correct pins bridged and the temp sensor disconnected, the fan ran?

With any of the other relays put in, the fan doesn't work with the temp sensor disconnected?

If so, I would be scrutinising the spade connectors inside the relay connector for rust, and lack of springyness.

[M700FGT]

That spare connector is for the AC system on Japanese Minis, I believe.

So to summarise:

With the correct pins bridged and the temp sensor disconnected, the fan ran?

With any of the other relays put in, the fan doesn't work with the temp sensor disconnected?

If so, I would be scrutinising the spade connectors inside the relay connector for rust, and lack of springyness.

 

 

Yeah thats all correct - Just to double check I tried all 3 yellow relays in the fan relay socket. I also tried it with and without the temp sensor connected. 

 

However as soon as you connect the 30 and 87 pins with wire the fan kicks in perfectly. Its also surprisingly powerful 

 

Ive really cleaned the relays up and the spades look good. The connector also looks perfected holds the relay tight. 

[Wiggy]

Hmmmm. Have you tried wiggling the wires at the base of the connector whilst the relay is in.

Also, humour me here, try bridging the relay again, but don't shove the wire right deep into the connector.

I'm just trying to rule out a dodgy connection.

The only other thing I can think of is to give the ECU earth a damn good clean. It's left of the brake servo. Unbolt it, clean it and the surrounding metal. Put back together.

If all that fails. You'll need to unplug the ECU connectors, find the light green/black wire and test continuity between there and the same wire at the relay. (Use the speaker icon on the multimeter. If it doesn't have one, select resistance and look for 0 ish Ohms. If nothing happens there'll be a break in that wire.)

Edited by Wiggy, 21 June 2018 - 05:55 PM.

[Bat]

Hi,

What he said.

Check you have voltage at the purple wire opposite the green black wire then test the green black wire as mentioned above pull the plug off the ECU first. If that's ok you have an ECU problem.

Cheers 

Edited by Bat, 22 June 2018 - 09:24 AM.

[M700FGT]

Evening guys,

 

I gave all the wires a damm good wiggle last night with no change. Fan starts up as soon as the wire touches, let alone going deep into the socket. 

 

I haven't metered the ECU yet as I'm not 100% sure where exactly i meet to meter. The ECU is the large silver box to the let and the connector going in is underneath, is that where you mean?

 

One new development - I managed to catch my neighbour this evening. He's not the social type, so not likely to come round and help. But he did build the most beautiful (and noisy) Mk1 Mexico with a Cosworth engine - so worth listening to!

 

I told him the fault, told him what i had replaced and all he kept saying was "Relay". I even told him i had swapped them round, and he just replied "the relay is wired wrong then". Now im note sure how this would happen, or why, but is it one to check off the list? I did mention ECU and he said just "No". Not that talkative lol 

 

So here is what i current have - the brackets are the pins on the relay

 

                            ( I )  30 Double purple

       ( I )  86 Single purple                ( I )  85 Green with black stripe

                            ( - )  87 Double black with green stripe

 

What do you think? 

 

 

 

 

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[Wiggy]

Your relay is wired correctly.

Go to the big silver box, then push the locking tab on the front of the connectors and pull at the same time. They'll be tight, so wiggle as you pull. Space is tight too, but it's doable.

Find the light green/black wire in one of the two connectors. Hold one of the multimeter probes on the wire here. (you may have to pop a paper clip or something in the connector block for something to probe.) Then put the other probe of the multimeter on the light green/black wire in the relay connector.

It should read 0 ohms. Ideally it won't, because you will have found the problem.

[Wiggy]

Oh, clean the ECU earth. Eyelet bolted to the the bulkhead (well, sort of), left of the brake servo.

[Bat]

Hi,

ItsI the ECU that turns the relay on, so yes its a possibility that it's at fault.

Cheers 

[Bat]

Oh and don't listen to cosworth people they know nothing, I'm one too lol

[Wiggy]

It would be very unusual for the ECU to be at fault. Possible though. I'd want to rule out absolutely everything else first.

[Bat]

It would be very unusual for the ECU to be at fault. Possible though. I'd want to rule out absolutely everything else first.

Too true!

[Eds.mini.lulu]

Good luck sorting this out nice to see some more minis local to me (Tonbridge)I managed to get my aux fan on my 93 carb fixed today shame it's not quite the same on an MPI.

[Carlos W]

Continuity test from the relay to the fan