Odd relay problem

[captain Byrne]

Odd problem here - When taking sharp bends or going over the occasional bump I get a clicking relay sound from the fusebox. However, if taking a large enough bend the coolant level/temp light also starts flashing. The temp gauge sits perfectly in the middle and the water in the upper coolant reservoir is full to the brim so can discount the level indicator. The clicking sequence is similar to that of a indicator relay. It obviously sounds like a loose wire somewhere but can't figure out why this would trigger the coolant light to flash and how two issues are connected as I assume the coolant level/temp light isn't connected to any relay. Thanks for any help as per usual.

[robertneill602]

Could point out a symptom with the wiring loom chafing on somewhere. Could strip the steering columb of its panels and check around the fusebox/relay plate. Have to check individual wires/loom for signs. The fusebox would click if it was removed without first disconnection of the battery -so not advisable. Seems to be from the flasher unit. Would check its brown/(white) grounding wire for corrosion at attachment to the vehicle body. Task is easier with Bays and Split-Screens.

[syncroandy]

TBH from what I've seen of older vehicle wiring (and I have quite a lot), most if not all T3's, even late models, are at risk of flakiness due to failing electrics. This is typically caused by deterioration due to water ingress etc. and just simply old-age, or by cack-handed modifications.

Thankfully, they are also extremely maintainable and most problems can be fixed relatively easily, with basic knowledge and tools.
Compared to modern vehicles anyway. Firstly the wiring is relatively easily accessible for troubleshooting and repairs, secondly they use 'industry standard', still widely available terminals types, thirdly they follow the awesome DIN standards, fourthly they are superbly well documented in the factory wiring diagrams.

[Robsey]

I suppose another thought could be the earth terminal 'crown' up on the inner wing near to the fuse panel.

Could easily be corrosion of the crown, it's fixture screw or wires going to it.

As it is caused by a turning motion, this would indicated a loose or damaged wire or its connector.

As mentioned - possible water damage from where water seeps in at the bottom corner of the windscreen if it is corroded.
Any water dribbles will run down the inner wing in this area.

The image below shows the fuse box bracket in my hand, and you can clearly see brown rust dribble lines from the bottom of the screen in my '83 van.

[Mocki]

it could also be the wiring in the engine bay floating about, making either a poor connection to the header tank,, or damaged and making a open circuit with the movement and force of the cornering 

it could be the coolant level id just on the cusp of low too,, but i would expect that to show on braking and acceration and youve checked the levels anyay ??

[captain Byrne]

Thanks for your replies. The coolant level is right up to the brim so have discounted the level indicator. There's no water ingress via the windscreen & the earth crown was all stripped & cleaned a couple of years ago so that's unlikely the problem but I will check it anyway. I'll have another rummage for loose wires/relays around the fusebox & wiring in the engine bay. The one thing which really puzzles me is how I can get a clicking relay and flashing temp light simultaneously. Seems strange but nothing really surprises me with these vans.

[Mocki]

Because relay 43 is the one that controls the flashing red light 
it maybe the actual relay is faulty ..... or has dirty contacts 

[captain Byrne]

Ahh thanks Steve - makes sense now. Cheers.

[Mocki]

It sometimes up above the fuse box, above the earth crown , up , up bit 

[AngeloEvs]

Modules 42 and 43 contain an electronic circuit that detects low coolant and triggers the LED. There are no  moving or mechanical parts inside.     

[Mocki]

Well theres a thing .... I’ve replaced several over the years, never taken one to bits 
every days a school day , even after 25 years of owning these ....

[captain Byrne]

Modules 42 and 43 contain an electronic circuit that detects low coolant and triggers the LED. There are no  moving or mechanical parts inside.     

So there's no relationship between a clicking relay & flashing temp light?
 

[AngeloEvs]

In the event of low coolant,  module 43 (or 42 as there are two types) sends a series of pulses to the circuit inside the temp gauge, these pulses trigger the led and continue until the ignition is switched off.   If your temp gauge led is flashing  intermittently while you are driving it is unlikely to be the module 42/43.    I would first remove the module 43 and see if the problem persists.   If the temp gauge led still flashes when going around bends then the fault could be something that is interfering with or interrupting the supply voltage to the dash.

The temp gauge led is controlled by a circuit in the gauge itself.    The circuit can be triggered by earth faults  and voltage changes.    I would check the x load relay.

[captain Byrne]

I would check the x load relay.

Thanks Angelo. Please excuse my lack of electrical knowhow but which is the x load relay?
 

[AngeloEvs]

Its a stab in the dark regards the X contact load reduction relay but usually numbered 18.   It reduces the load from the battery during start up by switching off components but I think it also reduces current through the ignition switch.   You really need a passenger to 'feel' the relays when you hear the clicking -  if a relay starts clicking you can feel the vibrations.