Pos & Neg terminals for attaching a tyre inflator

[DDJC]

Was checking the tyre pressures before my last trip and found that they were a tad low. Stuck the 12v socket plug on the dealer supplied tyre pump and nothing happened. Checked the fuse (10a) and it had blown. Replaced the fuse and tried again.

Good grief, it struggled. Wheezing and whining like me on a Monday morning. It barely moved the pressure then just got hot and shut down.

I bought a more powerful twin cylinder pump. 15a fuse and it too has a fag lighter socket plug. However, it also has the option of crocodile clips direct onto battery terminals.

My questions are:

1. On the Ducato base, where are the battery terminals to attach the crocodiles to? It is a bit of a faff to lift the battery box cover (see other post) every time you want to put some air in.
2. Can you use the leisure battery terminals to power the pump?
3. We have an EHU socket on our mains. Is keeping it plugged in while operating a pump a good thing? Or do I need to turn the engine over?

Thanks,

Dave

 

[denisejoe]

If you keep needing to put air in you have a puncture

 

[DDJC]

No, they should be about 70psi and I checked them and two were below 65psi. Just a bit of a top up.

 

[mfw]

I'd run off leisure battery better if you have solar but why drain starter battery power could cause problems with actually starting vehicle

 

[eddie]

Was checking the tyre pressures before my last trip and found that they were a tad low. Stuck the 12v socket plug on the dealer supplied tyre pump and nothing happened. Checked the fuse (10a) and it had blown. Replaced the fuse and tried again.

Good grief, it struggled. Wheezing and whining like me on a Monday morning. It barely moved the pressure then just got hot and shut down.

I bought a more powerful twin cylinder pump. 15a fuse and it too has a fag lighter socket plug. However, it also has the option of crocodile clips direct onto battery terminals.

My questions are:

1. On the Ducato base, where are the battery terminals to attach the crocodiles to? It is a bit of a faff to lift the battery box cover (see other post) every time you want to put some air in.
2. Can you use the leisure battery terminals to power the pump?
3. We have an EHU socket on our mains. Is keeping it plugged in while operating a pump a good thing? Or do I need to turn the engine over?

Thanks,

Dave

Use the jump start connection under the bonnet on nearside. If your battery wont run a compressor for a couple of minutes you have issues

If your worried about it start the engine and check/pump them up prior to driving off

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[SpeedyDux]

The Maplin heavy duty tyre inflator blew the 10A fuse for the 12v dash socket the first time I used it. After that it was OK and I still have it as a backup.

These small compressors all tend to get very hot and must be allowed to cool down every few minutes or else they will pack up.

You didn't say which Ducato yours is. The X290 handbook has a diagram showing a small cover under the bonnet you lift up to put one crocodile clip on and a bolt elsewhere for the other clip. Best for the more powerful compressors that draw a bigger current. The compressor lead should have an in-line fuse.

 

[tinks703]

On using a new tyre pump it blow a fuse, looked at the instruction needed 20 amp. When connected to the tyre would not run, so now I run the unit just as I connect to the tyre. No further problems 70 psi plus.
Tried a with a neibours pump same problem until I ran the pump and connect to tyre.
This is the first time I have had this sort of problem in all the years I have cars, vans and M/H.

 

[golly]

There is a positive terminal under the bonnet, under a plastic flap. I connect positive to that and negative to a decent earth to the chassis when i use tyre inflators.

 

[stevec]

When I use the inflator plugged into the 12v outlet I set the pump going before I attach to the valve. That way the load is gradual and the fuse doesn't blow. I may use the jump start terminals from now on though after I put some clips on the cable.

 

[pappajohn]

The Maplin heavy duty tyre inflator blew the 10A fuse for the 12v dash socket the first time I used it. After that it was OK and I still have it as a backup.

These small compressors all tend to get very hot and must be allowed to cool down every few minutes or else they will pack up.

I found with the MAPLIN, if you get rid of all the black plastic crap, the pretty bits, they tend to run a lot cooler
Mine would fill a 25ltr air tank from empty to 115psi in around 7 minutes running continuous without problem. It's around 7 or 8 years old now.

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[Reallyretired]

I use a cordless rechargeable one for checking and adjusting pressures So convenient I also have a biggish twin cylinder one if a tyre needs inflating from flat.

 

[ToBoldlyGo]

I carry either a mobility scooter battery for this purpose or a small ex car battery.

 

[Reallyretired]

Vaguely connected to this topic. Tyre pressures should be checked cold, but how cold is cold. There can be 5psi or more difference between a warm autumn day at 15C and a cold one at 2C never mind a summer day in Spain.

 

[jezport]

We fitted a heavy duty 12v socket directly to the battery with heavier cable and fused at 25a to run any higher load equipment like our 12v coffee machine and a compressor

 

[Richard n Ann]

Vaguely connected to this topic. Tyre pressures should be checked cold, but how cold is cold. There can be 5psi or more difference between a warm autumn day at 15C and a cold one at 2C never mind a summer day in Spain.

You could always use nitrogen ??

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[kevenh]

Vaguely connected to this topic. Tyre pressures should be checked cold, but how cold is cold. There can be 5psi or more difference between a warm autumn day at 15C and a cold one at 2C never mind a summer day in Spain.

And if the tyre pressure is right at 20C why adjust if the temp drops & now they’re low?
When the vehicle is moving and the tyres warm up the pressure will increase.
I don’t understand why vehicle instructions say add more pressure.

Wait until the temperature is a match for when you last set them and adjust if needed.
I look for a tyre that is offset to the others - that’ll be an indication of an issue.
Or the one tyre not in shade on my drive. ?

 

[Deneb]

Unless you're using F1 tyre heaters or you have serious brake problems at each wheel the warm tyre pressures will surely be just as affected by ambient temperature as the cold pressures, so it's always made sense to me to start with the recommended cold pressure whatever the temperature when checking them. A few psi here or there is of no concern though as long as they are all at compatible pressures so I don't go round altering mine for temperature variations unless I find them 5 psi or more over or under what I desire.

Be wary of serious underinflation or incompatible pressures across axles, but it's quite normal now to see recommended pressures for economy in vehicle handbooks which may be up to 10 psi or so higher than "normal" pressures to lower rolling resistance at the expense of passenger comfort.

 

[Reallyretired]

Being tight I use the economy pressures. This reduces rolling resistance and thus also the amount the tyre heats up in use. Possibly may reduce grip too, we all know about letting tyres down to improve grip on mud etc.

 

[pelican]

If you keep needing to put air in you have a puncture

Magic quote!