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  #1  
Old 1st April 2012, 03:53 PM
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brainbug007 brainbug007 is offline
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Default Need Some Help...

So I've been trying to finish off my electrics for good and get all the wiring in it's final places inside conduit tube etc. Because of using the donor loom, it's involved alot of shortening & extending wires etc. I've go everything connected up except for the cluster, cig lighter, fog light switch, and fan. I tried cranking the engine to make sure it all still worked and nothing happened

So I got my trusty multimeter out and started checking readings between the key barrel and the battery. Strangely I get continuity and voltage readings on the live (red) wire when the key is off or in position 1. As soon as I turn they key to position 2 or onto the cranking position, the voltage drops to 0?

I also tested the yellow/black wire at the barrel (which I think is the switched live?) and I get no voltage in any key position. I then checked the continuity between the battery and the yellow/black wire, and again it works when they key is off or in position 1, but nothing past that??

I'm guessing there's something wrong with my switched live circuit as it seems to get blocked when trying to start up? I've had a look at the wiring diagram and the only linked thing I could see to the yellow/black wire is the fan relay but I struggled to work out which one it is in the fuse box to see if there's something not right there

Any help or guidance where to go next would be appreciated!
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Old 1st April 2012, 04:19 PM
minicountryman1961 minicountryman1961 is offline
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Is there an interlock to make sure the clutch pedal is depressed while cranking??

Quote:
Originally Posted by brainbug007 View Post
So I've been trying to finish off my electrics for good and get all the wiring in it's final places inside conduit tube etc. Because of using the donor loom, it's involved alot of shortening & extending wires etc. I've go everything connected up except for the cluster, cig lighter, fog light switch, and fan. I tried cranking the engine to make sure it all still worked and nothing happened

So I got my trusty multimeter out and started checking readings between the key barrel and the battery. Strangely I get continuity and voltage readings on the live (red) wire when the key is off or in position 1. As soon as I turn they key to position 2 or onto the cranking position, the voltage drops to 0?

I also tested the yellow/black wire at the barrel (which I think is the switched live?) and I get no voltage in any key position. I then checked the continuity between the battery and the yellow/black wire, and again it works when they key is off or in position 1, but nothing past that??

I'm guessing there's something wrong with my switched live circuit as it seems to get blocked when trying to start up? I've had a look at the wiring diagram and the only linked thing I could see to the yellow/black wire is the fan relay but I struggled to work out which one it is in the fuse box to see if there's something not right there

Any help or guidance where to go next would be appreciated!
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Old 1st April 2012, 06:26 PM
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sounds really daft but have you checked that the battery terminals are tight?
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Old 1st April 2012, 06:49 PM
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Quote:
Originally Posted by minicountryman1961 View Post
Is there an interlock to make sure the clutch pedal is depressed while cranking??
The pedal box & cables aren't connected yet so it can't be that as it started and ran ok before when I was testing the edis & megajolt.


Quote:
sounds really daft but have you checked that the battery terminals are tight?
They're not mega tight, I'll have to check that just incase. I thought though I should hear the relay's in the fusebox click when I connect the battery? (which I don't hear btw)
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Old 1st April 2012, 07:11 PM
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Ok went out and check all the terminals and earths and tightened them right up and I still don't get any volts or continuity at the barrel when the key is in position 2 or 3. any other ideas of what I can check to find the problem?
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Old 1st April 2012, 07:19 PM
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Sounds like you have one of the earths or battery feeds missing.

TT
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Old 3rd April 2012, 12:47 PM
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That makes sense TT, as far as I can tell though the only circuit I don't have connected yet which might be affecting it is for the fan switch. I'm sure I had trouble with this before when I was first trying to get the engine to run and for some reason the fan switch had to be plugged in and earthed for it to work. I need to check the wires coming out of the fan relay but I can't work out which one it is as it doesn't give the number for it in the haynes manual on the wiring diagram (eg IV). Any idea how I can ID it or do you know what the code number or color of it should be in the fuse box?
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Old 3rd April 2012, 02:12 PM
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On Gus's Sierra the fan relay was on its own in a yellow holder, with a fuse built onto the side of it. It would have been under the dash originally.

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Old 3rd April 2012, 05:22 PM
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Quote:
Originally Posted by brainbug007 View Post

So I got my trusty multimeter out and started checking readings between the key barrel and the battery. Strangely I get continuity and voltage readings on the live (red) wire when the key is off or in position 1. As soon as I turn they key to position 2 or onto the cranking position, the voltage drops to 0?
I had a similar problem.
used a 6 pin universal ignition switch (came with no instruction notes) and after checking with multi meter found the common + supply, acc, on and start pins. Everything works well until one turns the key to start, and nothing happens....
After connection pilot test lamps to ignition switch to check the lights goes on at acc position, again on at on position but when turned to start, the on lamp went off and the start lamp lit! This explained why all systems died when starting and no juice supplied to ecu, coil etc when starting - obviously it will never go.

The solution was a simple jumper wire on the ignition pins to keep 12v continuity on the on position whilst cranking the starter.

Hope this helps
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  #10  
Old 3rd April 2012, 06:50 PM
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Thanks dave, that gives me a good starting point. Cant say I remember seeing a relay that had fuse built into it though. Just out of curiosity though, is that how the wiring looked behind the firewall on gus's completed car or did he put all that into conduit tube right up to the fusebox?
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