P38A Weird Hevac thing

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Ever have those days where you couldn't be more of a donkey if you tried?!? Did the job on the hevac unit this evening and spliced the wire from the cig socket, plugged it in and still nothing!!!!:mad:. Was about to throw car, soldering iron and the whole fecking hevac system into the sea when i remembered I'd taken the relays out of the fuse box to test them!!! Yay all is saved, you are probably saying to yourself right about now. No, no, no my good friend all is not saved, it was only after I'd put the relays back in that I realised that I'd spliced into a wire that gets 12v anyways and was perfectly fine!!!:mad::mad::mad::mad:!!! I thought it best at that stage to leave it until tomorrow for sanitys sake. I shall report back with more news when available and sanity levels are a bit more normal.:confused::rolleyes::confused:
 
Digweed said:
Ever have those days where you couldn't be more of a donkey if you tried?!? Did the job on the hevac unit this evening and spliced the wire from the cig socket, plugged it in and still nothing!!!!:mad:. Was about to throw car, soldering iron and the whole fecking hevac system into the sea when i remembered I'd taken the relays out of the fuse box to test them!!! Yay all is saved, you are probably saying to yourself right about now. No, no, no my good friend all is not saved, it was only after I'd put the relays back in that I realised that I'd spliced into a wire that gets 12v anyways and was perfectly fine!!!:mad::mad::mad::mad:!!! I thought it best at that stage to leave it until tomorrow for sanitys sake. I shall report back with more news when available and sanity levels are a bit more normal.:confused::rolleyes::confused:
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You need to check for 12 volts at cig lighter with ignition on first of all. Then take a wire from that to wire that goes to pin 1 on plug. No need to solder anything at first, just a wrap will do to prove function. Maybe a good idea at some point to ensure 12 volts at C1276 pin 6 BECM (White with pink tracer) on ignition just to ensure relay is actually working and that everything hasn't been rewired from what maybe a low amperage feed.
This may help. https://www.nanocom-diagnostics.com/downloads/preview/p38-becm
 
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I did check that first alright. Thanks for the suggestion on C1276. This BECM thing is going to be the death of me yet (possibly by electrocution)! still haven't got around to removing the second socket in the passenger footwell yet to try and get the eas working.
 
Digweed said:
I did check that first alright. Thanks for the suggestion on C1276. This BECM thing is going to be the death of me yet (possibly by electrocution)! still haven't got around to removing the second socket in the passenger footwell yet to try and get the eas working.
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Only one socket in passenger footwell to do with EAS it is the interface from the selector switch to the ECU.
 
Thanks. I did some searches on here a while back and the advice was to remove both. The two of my connectors were fairly corroded in spots. Anyways that's for another thread i have going. I'll try and sort this one first.
 
Digweed said:
Thanks. I did some searches on here a while back and the advice was to remove both. The two of my connectors were fairly corroded in spots. Anyways that's for another thread i have going. I'll try and sort this one first.
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Do both then. You may want to take a look at drivers side aswell.
 
Bit of a bust this evening. Got 12v onto the pin that was showing low, still not working. 12v showing on the back of the becm. at my wits end with this now.
 
Just thinking maybe i should check the voltage coming out from the connector instead of where i spliced into it. Might possibly be something wrong with the pin itself.
 
Digweed said:
Just thinking maybe i should check the voltage coming out from the connector instead of where i spliced into it. Might possibly be something wrong with the pin itself.
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Corroded connector pins are not uncommon and I have seen connector pins crimped to the plastic outer sheath of the wire where the wire itself has corroded away completely so what looked like a good connection was anything but..
 
Datatek said:
Corroded connector pins are not uncommon and I have seen connector pins crimped to the plastic outer sheath of the wire where the wire itself has corroded away completely so what looked like a good connection was anything but..
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I agree but maybe he is getting a little closer to sorting it. He can now be reasonably sure the break is between his splice and the plug.;)
 
Thanks for the replies. I snipped the wire going into the connector so i must check and see if there's good voltage coming from the cut end, had been showing 2.4ish volts at the pin. If I'm getting the full 12 from the cut end then it's the pin.
 
Got back looking at this today. I've no idea where to turn after this, all the pins on the white connector that are supposed to be getting 12v are showing 12v and it's still not working, doing my head in now. I've three different units and not one of them are showing anything other than lighting up when I turn on the headlights. nothing on the LCD and nothing lights up when I push any buttons. whenever I plug out the white plug and have the ignition on the fans comes on and thats it. I've a good battery in as she will start first turn of the key. it's getting on my nerves at the minute as I want to get the aircon going to get the damp from the inside.
 
Digweed said:
Got back looking at this today. I've no idea where to turn after this, all the pins on the white connector that are supposed to be getting 12v are showing 12v and it's still not working, doing my head in now. I've three different units and not one of them are showing anything other than lighting up when I turn on the headlights. nothing on the LCD and nothing lights up when I push any buttons. whenever I plug out the white plug and have the ignition on the fans comes on and thats it. I've a good battery in as she will start first turn of the key. it's getting on my nerves at the minute as I want to get the aircon going to get the damp from the inside.
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It's nothing to do with battery voltage, just lack of volts in the right places. You say have 12 volts on the pins of the connector, have you checked it gets to the printed circuit board on the other side? Have you checked that you have a good ground on pin 4 of the white connector actually on the PCB? If the HEVAC has power it will light up.
 
Are these things earthed via the becm? Is the hevac earthed that way?o_O possible to have the positive end but not the negative side of things:eek:
 
Datatek said:
It's nothing to do with battery voltage, just lack of volts in the right places. You say have 12 volts on the pins of the connector, have you checked it gets to the printed circuit board on the other side? Have you checked that you have a good ground on pin 4 of the white connector actually on the PCB? If the HEVAC has power it will light up.
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I have three units and not one of them has anything on the LCD, the button back lighting is all that comes on. I might be able to get back to have a look at it tomorrow, SWMBO might have different ideas!!
 
Mark Piercy said:
Are these things earthed via the becm? Is the hevac earthed that way?o_O possible to have the positive end but not the negative side of things:eek:
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Earthed via a splice to a point I couldn't easily access, I put a new earth for the HEVAC on my project car to prove a point. The OP may have volts on all the correct pins on the connector but that still doesn't mean it's reaching the PCB.
 
E0562 ground also grounds Inhibit switch. Ride height switch. Hevac. Cruise control and cruise ECU. Can't remember but did you say you were struggling with EAS also? Run a good ground to earth pin on plug and see what you get.
 
wammers said:
E0562 ground also grounds Inhibit switch. Ride height switch. Hevac. Cruise control and cruise ECU. Can't remember but did you say you were struggling with EAS also? Run a good ground to earth pin on plug and see what you get.
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Yep. There was nothing electrical working when i got this. The windows were sorted with a new switch pack. I'm getting continuity on the ground pin but I'm finding these things are so sensitive it's unreal. Just had a look at the board, there getting continuity between the pins and the board and can't see any damaged tracks, don't have anyanything to bench test it so i can go no further. I'll try a new earth and see.
 
Right finally got something! When i plugged it the connectors earlier i gave it a good shot of contact cleaner and when i plugged it back in there the lights for the direction buttons lit up and when they changed when i pressed them. Still nothing on the lcd but its a start. Must see if i can find some tiny files to try and get in and clean them.
 
Digweed said:
Right finally got something! When i plugged it the connectors earlier i gave it a good shot of contact cleaner and when i plugged it back in there the lights for the direction buttons lit up and when they changed when i pressed them. Still nothing on the lcd but its a start. Must see if i can find some tiny files to try and get in and clean them.
Click to expand...
The LCD could just be the bulb.
 
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