Relays - Some questions
Discussion
Unfortunately I think I am going to have a series of electrical questions over the coming days...I have a 'disaster' electrical woes (correct collective noun?) and need to get my head around whats happening.
Anyway, onto relays...
- Can someone advise of the model / type of relay on the Fuel pump and horn? If there is a list of all, that is even better.
- Is there any difference (apart from the obvious) between a relay housed in metal to one in plastic i.e. if the same diagram is on them, can the be considered a suitable replacement.
- Can a relay be tested to determine that its operating as intended? i.e. multimeter?
- Do relays frequently burn out? What would cause a burn out?
At the moment I have identified the following issues:
- Horn not working
- Engine fans not working
- Boot release button not working
I know that some of the relays were swapped about when it was in for other repairs and want to validate that the correct ones are in place.
Thanks
Aidan
Anyway, onto relays...
- Can someone advise of the model / type of relay on the Fuel pump and horn? If there is a list of all, that is even better.
- Is there any difference (apart from the obvious) between a relay housed in metal to one in plastic i.e. if the same diagram is on them, can the be considered a suitable replacement.
- Can a relay be tested to determine that its operating as intended? i.e. multimeter?
- Do relays frequently burn out? What would cause a burn out?
At the moment I have identified the following issues:
- Horn not working
- Engine fans not working
- Boot release button not working
I know that some of the relays were swapped about when it was in for other repairs and want to validate that the correct ones are in place.
Thanks
Aidan
I'm no electrical expert, but I have picked up a few tips.
To test your fuel pump relay on the umbilical cord in the pax footwell (normally one of two grey coloured relays). You can swap it with the ignition relay and then see if the fuel pump primes. If it doesn't, you may have a sticking or faulty relay. The replacement item is a Bosch AFU2913L and can be found here: http://www.ebay.co.uk/itm/140929423310. I think all of the relays are now plastic (manufacturing costs).
As for the various things not working, I would also test the fuses. You could try swapping a few of the relays around to see if it makes a difference. As for the fans, do you have a manual override switch and does it work? If you don't have the override switch and you have exhausted the relays/ fuses route, it would be worth checking the otter switch on the swirl pot and the wired connections to the fans that reside under the radiator as they have a habit of corroding.
To test your fuel pump relay on the umbilical cord in the pax footwell (normally one of two grey coloured relays). You can swap it with the ignition relay and then see if the fuel pump primes. If it doesn't, you may have a sticking or faulty relay. The replacement item is a Bosch AFU2913L and can be found here: http://www.ebay.co.uk/itm/140929423310. I think all of the relays are now plastic (manufacturing costs).
As for the various things not working, I would also test the fuses. You could try swapping a few of the relays around to see if it makes a difference. As for the fans, do you have a manual override switch and does it work? If you don't have the override switch and you have exhausted the relays/ fuses route, it would be worth checking the otter switch on the swirl pot and the wired connections to the fans that reside under the radiator as they have a habit of corroding.
The engine cooling fans and horn work from the same fuse, so check that fuse first, or check all the fuses and replace any that have blown, If they have been swapping relays round, make sure the fuel pump and ecu relays are in the correct socket on the umbilical, as they work slightly differently than the rest, these are either metal relays or brown bosch ones. Ensure the correct ones are fitted else the battery will drain quickly and you may/will have running issues.
Chuffmeister said:
I'm no electrical expert, but I have picked up a few tips.
To test your fuel pump relay on the umbilical cord in the pax footwell (normally one of two grey coloured relays). You can swap it with the ignition relay and then see if the fuel pump primes.
No please do not do this, it will have you chasing your tail.To test your fuel pump relay on the umbilical cord in the pax footwell (normally one of two grey coloured relays). You can swap it with the ignition relay and then see if the fuel pump primes.
The ECU and the fuel pump use similar relays. The ECU one is often called the ignition relay. The two relays are interlocked, that is to say the failure of the ECU relay will stop the fuel pump relay from working, therefore swapping them will not identify where the fault lies. Do not ask me how I found this out, but that is a few hours of my life I would like back, though hopefully, as I have shared this with lots of other Tiv owners it will have helped them to avoided wasting their time.
Relays are easy to test - you need a multimeter and a 12v supply. Have a look at the picture on the sIde. It's basically an electromagnetically operated switch. when 12v is supplied to one of the coil terminals and the other is earthed, the electromagnet is activated and switches the contacts. Depending on the type of relay, this will shift continuity between contacts if a 5 pin, or on/off if 4 pole. The pictogram wll show whether it is normally open or normally closed. With a 12v source you can check what the relay is switching with a multimeter.
Worth knowing is that the relay contacts have standard numbers:
85/86 are the coil terminals, and 30, 87, and 87a the switching terminals, so power acorss 85 and 86, and check continuity between 30 and 87, and 30 and 87a
Good web page here: http://www.bcae1.com/relays.htm
No difference between metal and plastic AFAIK.
HTH
Worth knowing is that the relay contacts have standard numbers:
85/86 are the coil terminals, and 30, 87, and 87a the switching terminals, so power acorss 85 and 86, and check continuity between 30 and 87, and 30 and 87a
Good web page here: http://www.bcae1.com/relays.htm
No difference between metal and plastic AFAIK.
HTH
NiceCupOfTea said:
No difference between metal and plastic AFAIK.
HTH
The relays do the same job but I would recommend the plastic ones as the metal ones tend to corrode in the footwell and this then contaminates the internals of the relay, it takes a long time for this to happen though.HTH
A very good and simple description of relay testing, some can make it quite confusing.
Chuffmeister said:
I'm no electrical expert, but I have picked up a few tips.
To test your fuel pump relay on the umbilical cord in the pax footwell (normally one of two grey coloured relays). You can swap it with the ignition relay and then see if the fuel pump primes. If it doesn't, you may have a sticking or faulty relay. The replacement item is a Bosch AFU2913L and can be found here: http://www.ebay.co.uk/itm/140929423310. I think all of the relays are now plastic (manufacturing costs).
Wow, that's a tidy little markup on that, they're about £6.00 cost.To test your fuel pump relay on the umbilical cord in the pax footwell (normally one of two grey coloured relays). You can swap it with the ignition relay and then see if the fuel pump primes. If it doesn't, you may have a sticking or faulty relay. The replacement item is a Bosch AFU2913L and can be found here: http://www.ebay.co.uk/itm/140929423310. I think all of the relays are now plastic (manufacturing costs).
Pink_Floyd said:
jamienshelly said:
The engine cooling fans and horn work from the same fuse, so check that fuse first
On my 1998 I have seperate fuses and relays for each fan, I think it depends upon what relay/fuse board was on the shelf at the time. NiceCupOfTea said:
Relays are easy to test - you need a multimeter and a 12v supply. Have a look at the picture on the sIde. It's basically an electromagnetically operated switch. when 12v is supplied to one of the coil terminals and the other is earthed, the electromagnet is activated and switches the contacts. Depending on the type of relay, this will shift continuity between contacts if a 5 pin, or on/off if 4 pole. The pictogram wll show whether it is normally open or normally closed. With a 12v source you can check what the relay is switching with a multimeter.
Worth knowing is that the relay contacts have standard numbers:
85/86 are the coil terminals, and 30, 87, and 87a the switching terminals, so power acorss 85 and 86, and check continuity between 30 and 87, and 30 and 87a
Good web page here: http://www.bcae1.com/relays.htm
No difference between metal and plastic AFAIK.
HTH
Good information. As an aside, it's a bit confusing as to why they've used the numbers which ended up becoming standard!!Worth knowing is that the relay contacts have standard numbers:
85/86 are the coil terminals, and 30, 87, and 87a the switching terminals, so power acorss 85 and 86, and check continuity between 30 and 87, and 30 and 87a
Good web page here: http://www.bcae1.com/relays.htm
No difference between metal and plastic AFAIK.
HTH
Oldred_V8S said:
No please do not do this, it will have you chasing your tail.
The ECU and the fuel pump use similar relays. The ECU one is often called the ignition relay. The two relays are interlocked, that is to say the failure of the ECU relay will stop the fuel pump relay from working, therefore swapping them will not identify where the fault lies. Do not ask me how I found this out, but that is a few hours of my life I would like back, though hopefully, as I have shared this with lots of other Tiv owners it will have helped them to avoided wasting their time.
I was told to do this by Fernhurst TVR...???The ECU and the fuel pump use similar relays. The ECU one is often called the ignition relay. The two relays are interlocked, that is to say the failure of the ECU relay will stop the fuel pump relay from working, therefore swapping them will not identify where the fault lies. Do not ask me how I found this out, but that is a few hours of my life I would like back, though hopefully, as I have shared this with lots of other Tiv owners it will have helped them to avoided wasting their time.
Before you go chasing an electrical / fuse / relay problem with the horn just make sure the steering wheel end is all working correctly.
Test the wire on the back of the button is OK. Pull the button out and ground the wire on the back of it (there should be just one and its black). If that works the problem is the button.
Also check the wire is connected at the other end. Its a short wire to a bullet connector on the steering ring. You may have to remove the shroud to check this, I can't remember.
Been there, done that, lesson learned the hard way.
Test the wire on the back of the button is OK. Pull the button out and ground the wire on the back of it (there should be just one and its black). If that works the problem is the button.
Also check the wire is connected at the other end. Its a short wire to a bullet connector on the steering ring. You may have to remove the shroud to check this, I can't remember.
Been there, done that, lesson learned the hard way.
Be very careful here! The 5 pin relays used in the ECU are wired internal so that two contacts are switched live at the same time. These physically the same as the more common two way relays that switch either one or the other contact live alternately, but are NOT inter changeable. The ECU ones also have flywheel diodes built into them so they dont spike the ECU electronics when they switch. Do as you will with the horn and fans, but keep to OEM / Bosch relays for the ECU. The loss of the main relay in the ECU loom will stop the fuel pump relay from working as the main relay provides 12v to the FP relay.
Chuffmeister said:
Oldred_V8S said:
No please do not do this, it will have you chasing your tail.
The ECU and the fuel pump use similar relays. The ECU one is often called the ignition relay. The two relays are interlocked, that is to say the failure of the ECU relay will stop the fuel pump relay from working, therefore swapping them will not identify where the fault lies. Do not ask me how I found this out, but that is a few hours of my life I would like back, though hopefully, as I have shared this with lots of other Tiv owners it will have helped them to avoided wasting their time.
I was told to do this by Fernhurst TVR...???The ECU and the fuel pump use similar relays. The ECU one is often called the ignition relay. The two relays are interlocked, that is to say the failure of the ECU relay will stop the fuel pump relay from working, therefore swapping them will not identify where the fault lies. Do not ask me how I found this out, but that is a few hours of my life I would like back, though hopefully, as I have shared this with lots of other Tiv owners it will have helped them to avoided wasting their time.
But like Blitzracing writes above, the failure of the ECU one will stop the FP one from working, so swapping them will not help.
Chuffmeister said:
Oldred_V8S said:
Interesting.
But like Blitzracing writes above, the failure of the ECU one will stop the FP one from working, so swapping them will not help.
Well, goes to show, you learn something everyday!But like Blitzracing writes above, the failure of the ECU one will stop the FP one from working, so swapping them will not help.
Wow, loads of useful information! Unfortunately a flat battery (perhaps related) prevented me taking a look this morning and work stopped me looking this evening...
I think my first course of action is to short the connections going to the otter switch and see if I have fans. When I press the horn I just hear the relay click
I think my first course of action is to short the connections going to the otter switch and see if I have fans. When I press the horn I just hear the relay click
Didn't notice if anyone mentioned the fans wiring, which lies under the radiator. When I had no fans I tested the otter switch by pulling the wires half off and then, with the ignition on, I put a screwdriver across the otter switch and one fan came on.
Got the engine hot 95 degrees, no fans, shorted the otter, fans. Bought new otter switch. Mine (99 Chim) was low down on the left hand side of the rad. Brass thingy. 30 mm socket required. About a tenner. 92 on, 85 off.
The two fans on my Chim are wired separately and the connector in the middle of the wires was corroded and needed a waggle and then a clean to make the second fan work.
Horn - worth checking that the wires are on the loud bit properly.
Boot release. I have never had fuses blow other than the 100 amp. Try the connections. Is there a solenoid somewhere?
Got the engine hot 95 degrees, no fans, shorted the otter, fans. Bought new otter switch. Mine (99 Chim) was low down on the left hand side of the rad. Brass thingy. 30 mm socket required. About a tenner. 92 on, 85 off.
The two fans on my Chim are wired separately and the connector in the middle of the wires was corroded and needed a waggle and then a clean to make the second fan work.
Horn - worth checking that the wires are on the loud bit properly.
Boot release. I have never had fuses blow other than the 100 amp. Try the connections. Is there a solenoid somewhere?
Edited by QBee on Tuesday 10th September 23:30
Well, my small issues are now a major issue.
I placed my newly charged battery into the car and tried the alarm fob. Doors still not locking / unlocking from the fob -this issue is what led me to think that the battery was flat. Button on the centre console works OK though.
Car started OK but then I tried the wipers which no longer work or the indicators, both which were working previously. The only thing that has changed is that I inserted a fuse for the horns that seemed to be missing since being returned from the garage.
Could this be water ingress causing this? Any ideas where I should be looking?
Anyone recommend an auto electrician in or around Glasgow?
I placed my newly charged battery into the car and tried the alarm fob. Doors still not locking / unlocking from the fob -this issue is what led me to think that the battery was flat. Button on the centre console works OK though.
Car started OK but then I tried the wipers which no longer work or the indicators, both which were working previously. The only thing that has changed is that I inserted a fuse for the horns that seemed to be missing since being returned from the garage.
Could this be water ingress causing this? Any ideas where I should be looking?
Anyone recommend an auto electrician in or around Glasgow?
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