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Discussion Starter #1
Hi all not been on here for a fair while as i bought a T25 wanted to go back in time a bit lol ( had a 2.5 Tdi ) still like to read stuff about T4s etc any way helping a friend out who as a 2.4 d m reg he as two probs going on one is van fails to turn over and dash lights go out ! total power failier but only now and again ! and secound is relay 38 buzzes like mad ! so need to know what that does and it shouldnt be buzzing like mad unless i am wrong ! and what relay powers the starter/glow plug circuit think its 104 but i have nothing to go on help pls :)
 

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Looking at the wiring diagrams, it looks like relay 38 is associated with the coolant pump system. When the engine is running it should receive a supply from the D+ wire opening the relay and the normally closed contact to the pump motor. Presumably you must have a faulty relay of a fault on the D+ cable causing the relay to chatter.
 

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Discussion Starter #5
Ok guys this is a 2.4 d i dont know anything about coolant pump system and if this as one does it ? my T25 does is it on the same line ? fully understand how the relay works and i have suspected a faulty relay ! if the relay was kicking in and out would it not be triggering the coolant pump to be switching on and off ? if these have an electric pump ! not my van so i cant just have a look easy as this is a friend and he keeps the van lol and he knows nothing about spanners etc !
oh thanks for the replys by the way !! please give me info if you can thanks
 

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My understanding is that the relay works in conjunction with the coolant temperature switch. If the temperature of the coolant is too high, the pump runs (this is in a situation when the the engine is not running). The relay only enables the coolant pump switching via the coolant temperature switch.

The normally closed relay is energised by the alternator D+ signal opening the contact that feeds the coolant temperature switch. When the engine is not running the relay contact is made and enables the coolant switch to bring on the coolant pump if required due to the temperature in the pipework. So in essence the pump will only run if the temperature is high or if you short out the pump enable switch with the engine in the off position.
 

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Discussion Starter #7
Thanks for the replys should not be to much problem to sort out then !! now i know what it is ! T:
 

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Remove the 109 relay take cover off look for the top two small terminals check the solder have not dry jointed thats what I had on mt 2.4
 

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There is no 109 on a 2.4D. According to my info the coolant run on pump is fed by a permanent + and grounds via the 4 pin temp sender G2. There is no reason for there to be a relay preventing this pump from operating when the engine is stationary, this is the whole purpose of this pump, to continue circulation after the engine stops. Can you say which position this relay is in?
 

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Again check the earth on the engine by the vac pump, i left mine loose and it caused glowplug relay to chatter i think waterpump is earthed on the same bolt
 

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There is no 109 on a 2.4D. According to my info the coolant run on pump is fed by a permanent + and grounds via the 4 pin temp sender G2. There is no reason for there to be a relay preventing this pump from operating when the engine is stationary, this is the whole purpose of this pump, to continue circulation after the engine stops. Can you say which position this relay is in?
Martyn, J235 (relay 38) opens the NC contacts via the D+ from the alternator and therefore preventing the pump running when the engine is running. It inhibits the run on puimp and the pump is therefore only allowed to run when the engine is off and is then controlled via the coolant temp sensor.

 

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Martyn, J235 (relay 38) opens the NC contacts via the D+ from the alternator and therefore preventing the pump running when the engine is running. It inhibits the run on puimp and the pump is therefore only allowed to run when the engine is off and is then controlled via the coolant temp sensor.

Thanks Paul, I missed that. Where is that diagram from? It doesn't show it in Elsa.
 

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Thanks Paul, I missed that. Where is that diagram from? It doesn't show it in Elsa.
I dragged that picture up from the T4 Wiki site at the time:
http://www.t4-wiki.de/wiki/J235

I only dragged it up from there as I was out fishing and on my iphone replying. It was easier to use that than to try and trawl through online wiring diagrams and didn't have access to Elsa etc.

It seems strange that Elsa doesn't mention it though, so perhaps I'm barking up the wrong tree? Will have to browse through my own copy of Elsa to see.

Interesting stuff...
 

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It could be a model year thing. My Elsa only has info for 1998 on models.
 
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