V6 Engine won't turn over

[BongoBonkers]

Hi, I wonder if anyone has any ideas? Our V6 won't start. Have checked battery voltage, 12.4 or so. Gear definitely in park. All the electrics come on as they should but when you turn the key to the start position there is just silence, no turn over at all. It appears that something is happening though because turning the key to the start position causes the coolant alarm to sound (as if when you turn the key on 1st thing) so some connection is being made somewhere. I thought it might be the ignition switch but this does not look like an overly easy item to replace so I thought I would ask on here for any ideas before I start swapping out parts semi-blindly. Maybe starter motor?

Does this ring a bell with anyone? It has an alarm and immobiliser but I think they are behaving as they ought to, central locking working as usual. Have tried spare key and alarm fob also, no luck.

Thanks for any input, Dave

[g8dhe]

Can you hear the relay A2-04 click as you turn the Ignition key to Start, see diagram below.
The Coolant alarm should turn OFF when you turn the Ignition key to Start on the Haydn alarm as its power should come from the IG2 circuit.
Has there been any work carried recently or any changes at all ?

Locations;

[BongoBonkers]

Hi Geoff

No click that I can hear. Nothing has changed that I can think of, we've had the van for 14 years as well so I am well used to it's 'eccentricities'. AA coming this afternoon so hoping to get a diagnosis from them.

[BongoBonkers]

I think the coolant alarm does go off when you turn the key to start position. Then when the key returns from the start position the coolant alarm sounds it's test buzzer as I guess it now has power again. I am at work so cannot 100% confirm but think that is correct

[BongoBonkers]

AA man couldn't get it going but he suspects starter motor. Does anyone know by any chance whether it's best to attack the starter from below or above?

[Ian]

I've got a reconditioned V6 starter motor here at Bongo Towers. Email me if interested [email protected]

[BongoBonkers]

Removed starter and tested, that is the problem. Only lasted 22 years, will email Mazda for warranty claim! Thanks for all help

[Hazzobongo]

Its probably just the carbon brushes, changed mine on a hilux and had no more problems with it, it began letting me down and just clicking off and on for six months, sometimes it would turn over and other times not just the dreaded click.

[BongoBonkers]

Unfortunately it is not fixed. I had the starter reconditioned and it still does not turn over at all. The only difference from before is that now there is a clicking noise when I turn the key to start. I have traced that noise to a H270 relay located on the wall to the left of the starter battery as you are looking at the vehicle from the front. There is some evidence of overheating on the wiring leading to that relay (as in the blue wire is blackened). I am not great with electrics at all but my instinct was to replace the relay and see how we go but the fact that it is clicking implies that at least the electro magnetic element is still working but perhaps some other part of it could be faulty? Does anyone have any ideas or experience of H270 relay issues?

[TheLongRoad]

If the wires have turned black due to heat build up, I’d be checking the socket where the relay slots into. Possibly a bad connection has caused an arc and melted stuff. I’m sure you can test relays - could save a bit rather than replacing parts along the line until it’s resolved.

[g8dhe]

Relays have two main parts;
1. The coil that generates the magnetic field,
2. The contacts that are attracted together by the magnetic field.
It sounds like the coil is working and creating the magnetic field, the contacts are being attracted together hence the click but the contacts themselves are damaged and not making proper contact. If its an H270 relay then it should be possible to pull the relay out and remove the cover to inspect the contacts if there damaged then I would suggest replacing the entire relay, although short term you may be able to clean the contacts enough to work for a short while.

[BongoBonkers]

Hi Geoff

Thanks for your help. We have opened the H270 relay and tested it by applying 12V to the coil and testing continuity over the other 2 terminals. The contacts open and close correctly as far as we can see and there is continuity when power is applied. We have checked what we think is the starter motor fuse (10a) under the bonnet and it seems OK. We have put a multi meter in the socket with the fuse removed and cannot get a reading when the key is turned.

We reassembled and the H270 relay still clicks when the key is turned. So power is getting that far. I am stumped really. And even more stumped that I can't even easily get it to a garage.

[g8dhe]

Well if the relay is all working but the starter isn't making any noises at all, you can check that 12 volts is reaching it via the relay, this power operates the solenoid and contactors within the starter, the contactors then connect the main power to the starter windings. A common problem is the contactors have burnt/worn out and need replacing, provided your not a COLD START system for Northern Japan then these are replaceable otherwise they are not as they are sealed within the starter motors itself. New contactors are available on eBay various types of kits https://www.ebay.co.uk/sch/i.html?_from ... s&_sacat=0
also looks like the Cold Starters are available as well.
Replacing the contacts are covered in this Youtube https://www.youtube.com/watch?v=5pnySma88gY

[nth]

Does the engine start if you give the solenoid 12v when the ignition is switched on? Are you getting 12v to the solenoid when you try to start the engine?

[BongoBonkers]

I was wondering if there was a way I could kind of 'jump start' the starter motor? So if I make up a new wire and attach it to the little tab on the solenoid and spark it with 12V do you think that should operate the starter if the ignition is on? I am hoping so. It is driving me crazy. We replaced H270 relay anyway to be sure as it didn't cost much but it's still all dead.