924 wiring woes
Discussion
You may have seen my thread on saving a 924 here
The car was a non-runner when we got it. The wiring was in a sorry state having been fitted with various different alarm systems at various points in its life. Relay/Fuse board was dripping wet & there had also been a fair bit of bodgery done .. such as replacing failed relays with random switches added in various places etc. None of this particularly stressed me as I'm pretty ok with electrickery.
However,.... I am struggling with one thing that I'm hoping someone here may be able to help with:
Having removed the bodgery & cleaned up the fuse/relay box, I refitted it all with the wiring as close as I could tell to how it should be (Haynes wiring diagrams for this car aren't the greatest) My plan was to see what worked and what didn't and go from there.
Ignition on:.... All good, but no sign of the fuel pump running. Until I turned off the wipers, which had been on by chance. As the wipers reached the point where self park should kick in (it didnt) the pump stared running. I repeated the exercise and yes the pump actuation was definitely linked to the wipers being turned off at the top of the sweep!. I decided to give the starter a go - just make sure everything turns ok, and to my surprise the tach needle bounced as it cranked and after only a couple of seconds it fired up and ran like a dream having stood for 7 years!
Somewhat elated at this, I set about finding out why the wiper operation should have any effect and first point to check was earths of course. I removed the two earth blooms from under the dash (corroded) and cleaned them up and that sort of fixed it.... I say sort of, because now I can't get the pump to run at all (unless I bridge the relay) and even then I get no tacho bounce on cranking and certainly no starting.
I am suspecting the relay as I cant get it to energise at all.
The w/d says
Pin 15 +ve ign feed
pin 31 Earth
Pin 30 +ve feed from batt
Pin 87 Feed to pump
Pin 1 T1 on the coil
It is this last pin 1 connection where my confusion lies. Is this a feed TO the coil from the relay or FROM the coil to the relay? There is talk on the web about the relay needing not only a feed from the ignition (switch) but also a 'pulse' feed from the ignition system generated by the crank sensor. but nothing in the manual about this.
I cannot get the relay to energise by using pins 15 and 31 so normally I would just pronounce the relay duff but the confusion over pin 1 causes me to hesitate before ordering nigh on £40 squidsworth of relay?
If I bridge the relay (30 & 87)the pump runs but still no tach needle bounce & no start
In short, is it a fault with the relay causng lack of 'pulse or vice versa!?
BTW It's a 2.0 NA so NO DME RELAY
I would be grateful for any advice on this.
Cheers,
Chris
The car was a non-runner when we got it. The wiring was in a sorry state having been fitted with various different alarm systems at various points in its life. Relay/Fuse board was dripping wet & there had also been a fair bit of bodgery done .. such as replacing failed relays with random switches added in various places etc. None of this particularly stressed me as I'm pretty ok with electrickery.
However,.... I am struggling with one thing that I'm hoping someone here may be able to help with:
Having removed the bodgery & cleaned up the fuse/relay box, I refitted it all with the wiring as close as I could tell to how it should be (Haynes wiring diagrams for this car aren't the greatest) My plan was to see what worked and what didn't and go from there.
Ignition on:.... All good, but no sign of the fuel pump running. Until I turned off the wipers, which had been on by chance. As the wipers reached the point where self park should kick in (it didnt) the pump stared running. I repeated the exercise and yes the pump actuation was definitely linked to the wipers being turned off at the top of the sweep!. I decided to give the starter a go - just make sure everything turns ok, and to my surprise the tach needle bounced as it cranked and after only a couple of seconds it fired up and ran like a dream having stood for 7 years!
Somewhat elated at this, I set about finding out why the wiper operation should have any effect and first point to check was earths of course. I removed the two earth blooms from under the dash (corroded) and cleaned them up and that sort of fixed it.... I say sort of, because now I can't get the pump to run at all (unless I bridge the relay) and even then I get no tacho bounce on cranking and certainly no starting.
I am suspecting the relay as I cant get it to energise at all.
The w/d says
Pin 15 +ve ign feed
pin 31 Earth
Pin 30 +ve feed from batt
Pin 87 Feed to pump
Pin 1 T1 on the coil
It is this last pin 1 connection where my confusion lies. Is this a feed TO the coil from the relay or FROM the coil to the relay? There is talk on the web about the relay needing not only a feed from the ignition (switch) but also a 'pulse' feed from the ignition system generated by the crank sensor. but nothing in the manual about this.
I cannot get the relay to energise by using pins 15 and 31 so normally I would just pronounce the relay duff but the confusion over pin 1 causes me to hesitate before ordering nigh on £40 squidsworth of relay?
If I bridge the relay (30 & 87)the pump runs but still no tach needle bounce & no start
In short, is it a fault with the relay causng lack of 'pulse or vice versa!?
BTW It's a 2.0 NA so NO DME RELAY
I would be grateful for any advice on this.
Cheers,
Chris
Edited by H6CJF on Wednesday 17th April 10:31
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