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Whats this wiring?
Posted: Wed Nov 07, 2012 10:25 pm
by stuc
Was under checking length of glow plugs today and noticed a snapped wire on a connector.
It doesn't cause any problems, unless this is my glowplug problem, but can anyone tell me what it is.
There are a few connectors bundled together.

Re: Whats this wiring?
Posted: Wed Nov 07, 2012 11:10 pm
by Driver+Passengers
Four vacuum valves on top of that bracket (top of the intake manifold, under the accelerator cable).
Right-hand two are
cold-
start, left two are EGR (?) Is your EGR blanked or still active?
http://mazdabongo.wikispaces.com/Parts
Re: Whats this wiring?
Posted: Wed Nov 07, 2012 11:21 pm
by Northern Bongolow
if you remove or break an earth here the ecu thinks there is a fault and can stop the dash glow plug light working and turns them off, in some cases it can isolate the fuel pump and stop the bongo from startiing at all.
just below these solenoids is a bundle of earth straps that are bolted to the inlet manifold. (just seen in the last picture).
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 10:37 am
by jaylee
Agree with the comments above.. The EGR looks to have been blanked & the redundant
solenoids removed..?
From memory there is a 5volt currant coming off the ECU & it can do some funny stuff if any of it grounds when & where it shouldn't, especially the positive side...
If you wanted to tidy that aria up? There would be no harm in removing the connectors & shielding the cut wire ends...
If you do decide to cut them..? Do it one at a time, not both at the same time!!!

But you knew that any way!

Re: Whats this wiring?
Posted: Thu Nov 08, 2012 11:40 am
by stuc
It doesn't cause any problems, but how can you tell EGR valve is blanked off.I am not very mechanically minded, just bodywork.
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 11:47 am
by Driver+Passengers
Under your finger and along the top of the inlet manifold looks like your EGR pipe. If this is not there, you've been blanked, but as it's there you'll have to work out whether it looks like there is a couple of mm aluminium blanking plate or similar sandwiched between that pipe and either end to where it connects (inlet corner piece towards the front and EGR valve towards the rear).
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 1:04 pm
by rita
Hi stuc,
From the picture it looks like it is the wee extension loom going from the connector to the temperature sensor(ECT)I think it should have a blue and red/with a tracer (think it is green)wires.
Can you trace the loom back..
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 1:20 pm
by stuc
Temp sensor for what? I dont think my scavanger fans work but not sure how to check them, difficult to trace as it just disapears into a clump of wires.
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 1:52 pm
by rita
stuc wrote:Temp sensor for what? I dont think my scavanger fans work but not sure how to check them, difficult to trace as it just disapears into a clump of wires.
Its the Engine Coolant Temperature Sensor,it screws into the engine just below your finger,(In the picture)t this sensor is used by the ECU to perform various functions,one being the Glow plugs.
Cheers.
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 2:03 pm
by Driver+Passengers
Another being the rad fans!

Double check the wiring to it is present and correct (item 26 in the first picture
http://mazdabongo.wikispaces.com/Parts)
Scavenger fan is controlled by temp sensor poked down through the centre cowl (item 25).
Not that they're anything to do with EGR
solenoids.

Re: Whats this wiring?
Posted: Thu Nov 08, 2012 2:06 pm
by jaylee
stuc wrote:I dont think my scavanger fans work but not sure how to check them,
Scavenger fan the one in front of the engine you mean??
Scav fan sensor is by the handbrake... If you unplug the connector with the engine running the scav fan kicks in?? With the engine off if you short the connections or run to ground the scav turns on too... Plug the connection back, tun the ignition on & off & the fan will stop & sort of reset....?!! Or run a hairdryer over the sensor beneath the "saddle" & it should come on??

Re: Whats this wiring?
Posted: Thu Nov 08, 2012 4:05 pm
by stuc
jaylee wrote:stuc wrote:I dont think my scavanger fans work but not sure how to check them,
Scavenger fan the one in front of the engine you mean??
Thats the ones, I will give that a try, but sure I unplugged that at some point and they didnt kick in, but ignition might of just been on not engine running.
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 8:27 pm
by jaylee
Un plug it
start the engine... After a while the glow plug light will flash an error & the scav fan will come on.. When you stop the vans engine the scav fan will keep going... Plug the connector to the sensor back in then turn the ignition on & off, the fan will stop & reset...? Kind of!!
I left mine unplugged by mistake after doing a little electrical work...

I thought i was having a problem until i removed the centre console & saw it unplugged....

Re: Whats this wiring?
Posted: Thu Nov 08, 2012 10:12 pm
by stuc
jaylee wrote:Un plug it
start the engine... After a while the glow plug light will flash an error & the scav fan will come on.. When you stop the vans engine the scav fan will keep going... Plug the connector to the sensor back in then turn the ignition on & off, the fan will stop & reset...? Kind of!!
I left mine unplugged by mistake after doing a little electrical work...

I thought i was having a problem until i removed the centre console & saw it unplugged....

Great info will try when I get a chance.
Re: Whats this wiring?
Posted: Thu Nov 08, 2012 10:28 pm
by jaylee
It's the ambient temperature in the engine bay if too high that triggers the scavenger fan....
I fitted a scav fan warning light a while back...
It takes a live feed off the positive to the fan when triggered.
Then flashes a series of red leds in this gutted dial pod on the left. It also flashes blue for the alarm too!
To be honest, its only flickered briefly once the summer before last after a long trip from Bath to Suffolk??
