boycie

Active Member
Hi There was a thread on here about the Hevac control dated before 1999 not needing the small relay in the fuse box on the 1999 and after cars ,well my air con was not working correctly and I discovered the Hevac control had been changed to a 1996 model the car is a 1999 so I made a jumper lead fitted it and and bob's your uncle we have air con .So firstly thanks to whoever sussed that and secondly I bridged terminals 86 switched terminal and 87 supply terminal have I done it correctly ?.
 
Hi There was a thread on here about the Hevac control dated before 1999 not needing the small relay in the fuse box on the 1999 and after cars ,well my air con was not working correctly and I discovered the Hevac control had been changed to a 1996 model the car is a 1999 so I made a jumper lead fitted it and and bob's your uncle we have air con .So firstly thanks to whoever sussed that and secondly I bridged terminals 86 switched terminal and 87 supply terminal have I done it correctly ?.
Not if by supply terminal you mean a permanent live, the aircon will run continuously:eek:
 
Hi There was a thread on here about the Hevac control dated before 1999 not needing the small relay in the fuse box on the 1999 and after cars ,well my air con was not working correctly and I discovered the Hevac control had been changed to a 1996 model the car is a 1999 so I made a jumper lead fitted it and and bob's your uncle we have air con .So firstly thanks to whoever sussed that and secondly I bridged terminals 86 switched terminal and 87 supply terminal have I done it correctly ?.

Still same pin on Hevac that switches compressor clutch pin 7. Pre MY 1999 it was done direct after MY 1999 it pulls relay 3 which powers clutch from a fused feed. So if you have relay 3, and it is working properly it should power clutch, check fuse 27. This is only for MY 1999 and on made 1998 registered 1999 do not have relay 3 fitted or wiring for it. Fuse 27 has a different function prior to MY 1999.
 
Thanks Wammers with the relay fitted the air con compressor clutch engages for a second or two the larger of the two pipe,s gets cold then it gets warmer then a while later it clicks in for a second or two then drops out again ,I removed the relay and bridged the terminal that supplies the coil of the relay with the one that supplies the compressor it works fine so much so that the larger pipe was covered in frost when I was trying it heater vents are blowing cold .If I switch the air con off the compressor disengages and the pipe warms up but I want to check I have not done the wrong thing .
 
Thanks Wammers with the relay fitted the air con compressor clutch engages for a second or two the larger of the two pipe,s gets cold then it gets warmer then a while later it clicks in for a second or two then drops out again ,I removed the relay and bridged the terminal that supplies the coil of the relay with the one that supplies the compressor it works fine so much so that the larger pipe was covered in frost when I was trying it heater vents are blowing cold .If I switch the air con off the compressor disengages and the pipe warms up but I want to check I have not done the wrong thing .
Sounds like there is no control.
 
No sorry Datatec should have said ,when the pipework was frosty the air con was on low ,recirculation ,fans and at full speed as soon as I turned the fans down temp up the frost went
 
Thanks Wammers with the relay fitted the air con compressor clutch engages for a second or two the larger of the two pipe,s gets cold then it gets warmer then a while later it clicks in for a second or two then drops out again ,I removed the relay and bridged the terminal that supplies the coil of the relay with the one that supplies the compressor it works fine so much so that the larger pipe was covered in frost when I was trying it heater vents are blowing cold .If I switch the air con off the compressor disengages and the pipe warms up but I want to check I have not done the wrong thing .

You are going to get into trouble, take it to somewhere that does aircon to check over. Ideally you should fit the correct Hevac unit. Latest being JFC102540 less seats JFC102550 with heated seats. Diagnostics if you can get it on some may tell you a better story.
 
I have just sent a PM to Irish Rover it looks like it was him that started the ball rolling with this mod . Wammers I would love to get the correct hevac this is the second one I have tried I say must be post 1999 "yes yes " this is the one when I arrives its date stamped 1998 or before and will only work if I remove the relay and bridge the two terminals ,I have two bloody great Mastiffs in the back of the car at the weekend when we take them out ,and now its starting to warm up I need the air con ,they really don't like the heat inside a car even with all the windows open.
 
I have just sent a PM to Irish Rover it looks like it was him that started the ball rolling with this mod . Wammers I would love to get the correct hevac this is the second one I have tried I say must be post 1999 "yes yes " this is the one when I arrives its date stamped 1998 or before and will only work if I remove the relay and bridge the two terminals ,I have two bloody great Mastiffs in the back of the car at the weekend when we take them out ,and now its starting to warm up I need the air con ,they really don't like the heat inside a car even with all the windows open.

It's the part number you should be going for get the latest unit. Sometimes Hevacs are on eBay for a reason. They don't work. Buy one from a breaker you have some come back, not a private Joe.
 
You right Wammers but when I bought my car I had a 1996 hevac fitted so it did not have the correct part number .I found out that is why the air con did not work I took it to a air con specialist who recharged the system and told me the compressor was duff ,as I said I removed the relay and bridged two terminals as per the mod on here and it works fine But I would still love to get the correct part but no one seems to know there was a change in 1999 I have tried to get the part no from a couple of dealers and all I get is has it got heated seat's air con ect post or pre 1999 does not matter . If any one on here could find the correct part number or know were I could get the correct part I would be very grateful .I bet I can change a hevac control faster than most on here .
 
You right Wammers but when I bought my car I had a 1996 hevac fitted so it did not have the correct part number .I found out that is why the air con did not work I took it to a air con specialist who recharged the system and told me the compressor was duff ,as I said I removed the relay and bridged two terminals as per the mod on here and it works fine But I would still love to get the correct part but no one seems to know there was a change in 1999 I have tried to get the part no from a couple of dealers and all I get is has it got heated seat's air con ect post or pre 1999 does not matter . If any one on here could find the correct part number or know were I could get the correct part I would be very grateful .I bet I can change a hevac control faster than most on here .

Half the breakers on eBay know the square root of f*ck all.
 
Probably quite a little less than that Grrrrrr ,if you take a look most of the hevac controls are marked up 1994-2002 the bloody arguments I have had you would not believe .
 
Think if it was me I`d use a new stand alone relay fuse fed from the battery and use the original compressor live to switch the relay.
 
That does not work kds the hevac is looking for a voltage demand of about 3 amps to confirm that the compressor clutch has engaged a relay only pulls about 1/2 amp,I could put a dummy load across the relay coil .To be honest the hevac works but I would really like the correct unit, I have now found the correct part number which is JFC102550 if anyone wants to know
 
That does not work kds the hevac is looking for a voltage demand of about 3 amps to confirm that the compressor clutch has engaged a relay only pulls about 1/2 amp,I could put a dummy load across the relay coil .To be honest the hevac works but I would really like the correct unit, I have now found the correct part number which is JFC102550 if anyone wants to know

Do you mean the one i posted yesterday. Do you read the replies at all?:confused:
 
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Of course I do read your replies Wammers and I am grateful for the help and I think I have replied to most you have posted on my thread's. I did take the part number along to the dealer I am friendly with and confirm part number JFC 101890 which appears to be the part I have is a different beast that is why I said I now have the part number prior to your post the only number I could get was JFC101890.
 
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Of course I do read your replies Wammers and I am grateful for the help and I think I have replied to most you have posted on my thread's. I did take the part number along to the dealer I am friendly with and confirm part number JFC 101890 which appears to be the part I have is a different beast that is why I said I now have the part number prior to your post the only number I could get was JFC101890.

JFC101890 was fitted VIN number WA381431 to XA411504. JFC102550 is the latest version. Mine was made 1998 registered 1999 it has the latest JFC102550 fitted but no relay 3. Aircon works fine from it. But i do have a spare one just in case. :);)
 
You know the part number's and it makes sense to you, prior to me posting on here the only part numbers I could find was JFC101890,and to be honest I don't think the people I was asking gave a **** it was easier to say they did not know.If you have a spare JFC102550 how would you like to sell it or swap for a JFC101890 my one works fine if I remove the relay
and fit a jumper?.
 
You know the part number's and it makes sense to you, prior to me posting on here the only part numbers I could find was JFC101890,and to be honest I don't think the people I was asking gave a **** it was easier to say they did not know.If you have a spare JFC102550 how would you like to sell it or swap for a JFC101890 my one works fine if I remove the relay
and fit a jumper?.

Look round you can get them cheaper. RANGE ROVER P38 THOR HEATER CONTROL UNIT 99-02 JFC 102550 | eBay
 

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