More electrical probs

[Jonathan]

This car is driving me mad.

Fitted the SE starter to the GT3, took like 4 hrs to get the 2 bolts that had fused to the bell housing out - cleaned everything up all nice.

Redone the earth post so now I have under 1ohm to the battery - basically gave it a good tart up.

Day 2, connected the starter, done the checks - flicked the key. Engine whizzing round, superb !

Stop, start again, whizzing - fantastic.

1 last time and CLICK.......oh

Looks like the pinion is stuck, hit it a few times and try again.

Click....hmmmmm

Then it just went BANANAS !!!

The lights were coming up and down indipentantly - the binicle is flashing like an x-mas tree, even the brake lights were doing a little number - sure the alarm even started playing the national anthem at one point !!

Everything is fine until you hit the key and it just goes CLICK and the whole car goes dead - it's REALLY werid.

One thing I noticed was the boost gauge goes right over the right for some reason....just bizzar.

I'm thinking it's a sticking stater so I took it out, tried it - no probs, put it back same issue. i must have tried it about 50 times with no joy.

No shorts, perfect continuity between lives and earths - the car just goes mental !

I'm wondering if its the alarm thats gone cookoo, there's just no real symptoms - you try and start and the thing just CLICKS and everything goes dead, then it just goes berserk ! Relays chattering - crazy.

Oh the battery is pretty new - tried it on a freshy charged backup, same issue.

Actualluy had this on the old starter becuase the motor contacts were buggered - all it used to do was just a clikc a few times before starting, this is not the same.

Just completely doing my head in at the moment.

Edited October 30, 2007 by Jonathan

[98GT3]

There are a two things I would check to find out a little more of what is going on..........

1. Test the starter separately off the car. 2. Test the starting without actually having any power connected to the starter i.e. going through all the motions without the starter actually able to spin.

These tests should help determine if you have something like an internal short in the starter motor or something bad in the wiring that powers it.

Phil

98GT3

[superdavelotus]

Check your earth strap from engine to chassis, I think this may be you culprit (common fault with symptoms you are describing). Also check the connection again going to your starter.

The way to rule out your earth strap is to run a wire from the negative to the engine or better still the starter. If nothing, then at least you have ruled it out and it's only a 5 minute job.

Is the SE starter exactly the same as the GT3 one?

Dave

[Jonathan]

Phil :

1 & 2 done - starter works fine. It's been on the GT2 for a year and it always stated that instantly as well, never a problem.

With the red/white wire disconnected it's fine - the start relay kicks in, it only goes spazzo when the motor itself goes.

Dave :

I have re-done the earths, metered them out and they're fine to battery and to other earth points.

The GT3's starter motor was a 3rd party one - as I say it started the car twice but since then it's gone LOOPY !

I've had issues before like this when the battery is really low, there isn't enough power (mainly as the voltage drops off) to start the engine so the motor stalls and a shunt motor in stall is like a short circuit. The alarm cuts in and stops you blowing up the car lol.

It seems this is also happening now - the rear relays flutter like crazy - when you look at it the imobiliser and alarm controller actually stop these from working so I'm half wondering if there is something wrong there.

One thing I did notice was the alarm is flashing 3 times then off for a few secs then 3, then off - never seen that before.

I hate alarms.

[PVK 596Y]

Phil :

1 & 2 done - starter works fine. It's been on the GT2 for a year and it always stated that instantly as well, never a problem.

With the red/white wire disconnected it's fine - the start relay kicks in, it only goes spazzo when the motor itself goes.

Dave :

I have re-done the earths, metered them out and they're fine to battery and to other earth points.

The GT3's starter motor was a 3rd party one - as I say it started the car twice but since then it's gone LOOPY !

I've had issues before like this when the battery is really low, there isn't enough power (mainly as the voltage drops off) to start the engine so the motor stalls and a shunt motor in stall is like a short circuit. The alarm cuts in and stops you blowing up the car lol.

It seems this is also happening now - the rear relays flutter like crazy - when you look at it the imobiliser and alarm controller actually stop these from working so I'm half wondering if there is something wrong there.

One thing I did notice was the alarm is flashing 3 times then off for a few secs then 3, then off - never seen that before.

I hate alarms.

Checking the earth side with a meter is not a great deal of help, as you're not trying to put a couple of hundred amps through the connections when using the meter. It's got to be either a poor earth or as you say, the motor has jammed and is acting as a dead short. Whatever it is, the culprit will be getting very hot, so that might help you track it down. A known good battery would also be helpful.

Paul.

[Jonathan]

Well the odd thing is nothing's getting hot - and even when it's fitting, the battery is still 13.something volts so there is no short happening - nothing considereable is being drawn on the ammeter either. It's very strange.

Battery is known good, it started the car twice in a row plus I used a second battery incase.

Without chucking 100 amps through the car using a suitable load I can't really test the earth continuity. End of the day if the connection is solid (which it is) and there is low reading you're 99% sure the earth is good. I understand what you're saying about the meter - if the earth was only just about making contact you would get continuity but under load the small cross seciton would increase the resistance massivly as it got red hot, not happening though.

Everything is fine until you touch that position 3 and the motor clicks - then it dies for about 5 secs before going berserk !

I should really take a movie of it - it's like the car is having a seizure - the headlights had me rolling up, how do they move independantly like that ?!?!?

Brake lights come on too lol - although thats the ABS computer doing it's test.

Looking over the circuit for the umpteenth time I just cant see what's going wrong.

When the key is pos 3 the starter relay clicks and sends the pinion forward, the fly wheel is free because you select gear and see the thing moving so the engine's not seized (lol). The engine turned twice so it's not the motor (plus it's been tested off the car as well).

I've taken off the earths, cleaned the up, tested etc - no apparent probs there.

If you don't try and start it all the functions work perfectly - alarm works, stereo, lights, windows.

Try stripping the motor tomorrow, who knows might have stopped on a damaged part of the comm or something.

[wiseraven]

You say you're getting 13+ volts when it's going nuts. Have you checked that at the exact moment it starts to go nuts? It could just be a transient dip that sets it off and by the time you measure it, the voltage is back to normal.

Another possibility - is it possible you're getting some HT leakage? It doesn't have to be shorting (which would probably be terminal anyway), just induced voltage pulses could send the system haywire. The pulses would be short enough not to register on a voltmeter.

Phil

[superdavelotus]

Hi jonathan,

I know we've talked about earths and you're confident that yours is OK but to rule it out 100%, run a wire to the battery (try a jump lead or better still clamp something to battery and engine (or better still starter).

I wouldn't want you to strip your starter down again if later you find it's this.

Dave

[98GT3]

Hi Jon,

I am not sure from your wording if you have checked the starter motor off the car since it has started playing up. We know it was fine as it did turn your engine on a couple of occasions before it went wrong - if you haven't checked it since, it may have had a meltdown.

If you want to check your earth integrity, then you can do this by putting a meter set on DC volts and taking a reading between the car chassis and engine, while someone else trys to start it. Measuring the volt drop will tell you how good your earth connections are - the better the connection the lower the voltage drop.

Phil

98GT3

[PVK 596Y]

A couple of thoughts....

If the battery voltage is staying at 13+v when attempting to crank the engine, there's not much current being drawn. Normally you would get 8 or 9 volts across the battery terminals when cranking. That means a relatively high resistance in the circuit somewhere, either supply or earth side. Is there a good connection between the body of the motor and the engine?

Instead of stripping the motor, why not take it to South East Auto Electrical Services in Tovil, Maidstone. They will put it on a proper test rig and will tell you very quickly if it's OK. I think they will do this free (or at least for very little cash).

Paul.

Edited October 31, 2007 by PVK 596Y

[Autocross7]

This type of thing can be crazy for sure... not sure of your alarm system, but I have seen an alarm system relay go bad a cause some intersting issues? I would def. get it checked as suggested if possible. There does not seem to be a great place to start tracing since the starter checked and everything is 'berzerked' at once?

In the spirit of Halloween... you might need to get a hold of that little woman from Poltergiest?

Cameron

Edited October 31, 2007 by Autocross7

[Jeff Clements Danton]

just a suggestion, I had an S3 that used to do this, and it turned out to be a voltage regulator - worth checking as it cooks the battery eventually... hope that helps? :clover:

[CNH]

Have you checked the voltage cut off relay?

When properly working it is supposed to cut power to all except ignition, ecu and starter then cut back in all electricals when the key taken off the starter position. It makes similar symptoms to what you describe if this fails.

Calvin

[Jonathan]

Rebuilt the starter today, no probs with that (very nice actually) The comm is a bit worn but then again it is from 1989 !

Wont have time for a while to check the car.

I just wonder if my first thought was correct in that the starter is getting stuck forward and the voltage is dropping so low the alarm is cutting in.

I've got the laserline one - I remember when the battery goes low (when I had a duff one) the alarm was always cutting out the start sequence.

I'll give the jump leads a go just to check and see whats going on.

Voltage cut off, thats the drop out relay - it's very hard to tell becuase ALL the relays were going nuts - it's possible I'll just have to have a longer look, at least I know what I'll be doing at the weekend !!

Thanks for the suggestions.

[Jonathan]

Well pats on the back everyone who suggested earths.

Done what Dave suggested and put another earth on the car and it starts (sounds like it's sparking somewhere !!!) - take it off and it wont go.

The other test I done is why it's going mad.

Seems the starter is engaging and getting stuck which is pulling the motor in. Problem is without the good earth (still puzzled by that but there ya go) the motor wont crank so it draws and draws more current - I believe the car or the alarm has an over current protection which is cutting in to stop the starter from exploding - its the only thing that can be happening as the power dies the starter is still left in so as the trip is re-setting hence I get the relay chatter.

I know my flywheel is burred - this was from the old starter which wasn't really made for the car (not my modificaiton btw) - stationary gears are much more prone to stick than spinning ones so I'm happy now whats going on (phew).

Still can't work out what's gone wrong with the battery to engine earth - seems fine to me, 'spose I'll have to take it off and clean it again.

Anyone run extra earths in the car ?

Considering how much GRP cars have earth issues and how easily they can be overcome I wonder if it's worth having a little earth bus bar in there and running suplimentary earth much like you do in a house or something with earth bonding - not sure how it'd fair in the car what with electronics and parallel conductors. I remember my earth bond to the front of the car was somthing like 2 volts !!

I'll have to remember the one in the future - cheers all !

[Simon350S]

Doing a continuity check for your main engine earth is pretty meaningless

It will tell you its connected and will give you a reading but you will get a good earth reading if you ran a bell wire as a main engine earth, but you'd blow it to bits the moment you tried to start the car.....!!!

An old mini of mine was earthing itself through the throttle cable.....!!!!

Check the main braided straps between the chassis and the engine, and also the main strap from the battery to the chassis.....

Could be it looks good but is frayed/damaged almost completely through.....

Keep at it mate, you'll get there....!!!

Simon

[superdavelotus]

Hi jonathan,

Well good news is that you now know it's earths. Do you have a diagram showing where they all are? I may not necessarily be the engine to chassis one although this is the most favourite. Your local motor factor sells earth straps off the shelf. Bolt a new one in for now then look into where the other is failing. Have you check the cable from engine to chassis yet? It also could be one carrying the ignition inside the car?

[PVK 596Y]

Well pats on the back everyone who suggested earths.

Done what Dave suggested and put another earth on the car and it starts (sounds like it's sparking somewhere !!!) - take it off and it wont go.

Where exactly did you put the extra earth? Battery to chassis, battery to starter motor body, or where ?

If you move it around, it could tell you where the problem is located.

Paul.

[Jonathan]

On the continuity check, on the Esprit you can see the earth cables are there and pretty much tell whether they are secure - the idea was to see if I had something like 0.5 ohms or something to the battery - I KNOW putting an ohmeter on something like this is not going to tell me a huge deal but I didn't have access to an earth bonding tester so it's the best I could do.

Fact is I've worked on many vehicles with bad eartyhs and starting issues and lo and behold they have 1-2ohms restistance.

And the leakage of the previous starter I had on there was about 35 ohms becuase of the corroded terminals - so it's not an althogther meaningless excise.

The jump lead I put on was to the battery and to the startermotor fixing bolt on the bell housing so as close as possible - I took the engine block fixing off and had a look, nothing dirty on it at all but I wiped it over with a scouring pad and now it's OK - thats the only one that could cause the start to fauil as it's the closes return loop to the battery. Connected it back up and it worked so there was obviously something on the terminal which was reducing the CSA of the joint - perhaps the 3rd party starter needed less cranking current - who knows, seems to work now.

Think the sparking is the motor contacts dripping out, they were a bit pitted but loads of meat left on them (it is off a 90,000 mile car !)

The engine block to chassis was well rusted - I carefully took it off and ran a die down the thread to clean it up, would have thought all the earths are busted up I'll have to go over them sometime - big issue was if the '89 starter worked with the 97 car which it does so all is good.