G60 Ignition Relays - what does what?

[Alex_G60_Fanatic 0]

Hi fella's,

 

done a few searches but couldn't get a definitive answer to the question above.

 

What relays are used in the ignition circuit of a G60, and what do they do?

 

The reason for the question is that I have a non-starting car. I have changed the ignition switch and the starter motor and still the engine doesn't crank/turn over. The car push starts so i'm getting sparks/power to the plugs, isv, fuel pump etc. just the key doesn't turn the starter motor. So.. I'm changing some of the relays. Which ones do i need to replace? :confused4:

 

I'm going to check the voltage on the battery but TBH... I can bridge the gap on the starter and that turns but DOESN'T turn the engine flywheel... very strange, I thought the starter so long as it's spinning will jump out into the gear box and turn the engine... maybe I'm wrong

[Supercharged 2]

Nothing to do with relays mate but I would look at the alarm / imobiliser if fitted - maybe a fuse hidden somewhere...

 

All you do when you turn the key to crank is send 12V down the thick red / black wire to the starter solenoid, this engages the starter and cranks the engine. (The circuit for this only involves the battery and alternator)

 

Take the single wire plug off the starter solenoid and look for 12V when key is turned to crank, if you don't get any then it's an Alarm / Ignition / wiring issue

 

If you do get 12V then it's a dead solenoid / battery / earth wiring issue - could also be a problem with the brass bush in the gearbox etc...

 

Do you have AA cover or similar? - If so call them out, should be able to diagnose quickly.

[Alex_G60_Fanatic 0]

Nothing to do with relays mate but I would look at the alarm / imobiliser if fitted - maybe a fuse hidden somewhere...

 

All you do when you turn the key to crank is send 12V down the thick red / black wire to the starter solenoid, this engages the starter and cranks the engine. (The circuit for this only involves the battery and alternator)

 

Take the single wire plug off the starter solenoid and look for 12V when key is turned to crank, if you don't get any then it's an Alarm / Ignition / wiring issue

 

If you do get 12V then it's a dead solenoid / battery / earth wiring issue - could also be a problem with the brass bush in the gearbox etc...

 

Do you have AA cover or similar? - If so call them out, should be able to diagnose quickly.

 

Got the RAC out before, They said it was the starter motor. So just swapped that over on Saturday, refurbished one. Still wont crank.

 

I did have an immobilizer fitter but it's been disconnected for years, since before I bought the car... I'm unsure on the wiring for it? but i have no alarm ect.

 

Starter solenoid I assume is the little bit attached to my new starter? that looked fine... It all looked fine. The ignition switch was swapped over about 4 months ago, again a brand new one. :cuckoo:

 

I'll test for 12v tonight when i get back from work but I've had the battery attached to jump leads while trying to crank it and that didn't help.... I'm no good and electrics you may have noticed.

[Alex_G60_Fanatic 0]

wait... if my alternator isn't correctly connected would this make it not turn over either?

[Supercharged 2]

Yep... does it not do anything at all then???

 

When checking 12v to the solenoid plug maybe check the connector inside the plug, check the water seal is there etc...

 

Could then try feeding 12V straight onto the solenoid from the battery

[Alex_G60_Fanatic 0]

hmmm, i did change the alternator... maybe i didn't connect it up properly? How can I check?

[Supercharged 2]

Maybe stick a pic up but you can't really go wrong...

 

The car - does it do anything at all when you turn the key - ie turn slowly or dash lights dim etc??

 

Where was the starter from - I've had a refurbed starter from GSF that did what you describe becuase the solenoid was dead...

[Alex_G60_Fanatic 0]

Maybe stick a pic up but you can't really go wrong...

 

The car - does it do anything at all when you turn the key - ie turn slowly or dash lights dim etc??

 

Where was the starter from - I've had a refurbed starter from GSF that did what you describe becuase the solenoid was dead...

 

turn the ignition on and you hear the fuel pump priming, dash lights come on radio etc.

Turn the key to start position and you can hear a low "buzz" noise coming from the engine bay, lights dim (slightly) and that's it. Motor doesn't turn or anything.

The motor turns when i bridge the gap between the connections but i assume that cuts out the solenoid...

the motor I got was a original bosch starter... but from ebay. Was sold in it's original box. I got a picture of it here

[Supercharged 2]

Any luck dude?

[Purple Tom 0]

Might be worth checking all of the engine earths. I'm not sure about the G60 but the VR6 definitely has a crucial engine earth that is held by one of the starter motor securing bolts.

 

If that was missing or loose then it could potentially cause the problem you're having. Check the other earths and also the battery earth wire while you're at it too.

 

Tom

[Alex_G60_Fanatic 0]

Well, didn't get home till 7 last night but still decided to brave the weather and have a go! Got the multimeter out and got 11.89volts across the battery. So measured from the starter to the battery got 11.84v. Then tried the red/black wire from the ignition switch... Got nothing to begin with. Then pulled it off and stuck the multimeter into the plug then turned key and got 10v. Stuck it back on and now the starter motor clicks and try's to turn!! Woop! :D

 

Going to buy new battery as it was still REALY slow to turn over but I think my late night fiddling solved it! That ignition wire must have either been dirty or connected to the coil wrong. Eitherway happy days! :grin: