Ignition relay - now installed

[Ralf85]

I have been advised to fit a relay to bypass some of the cabling to reduce power drop between battery, ignition switch and starter motor. Is this option covered in the Bentley manual (I haven't got mine yet)? I cannot find the topic in the wicki. I believe this is a normal vw upgrade. Can somebody recommend the correct relay and where to get it. I want to get this sorted just after xmas. Cheers guys!

[lloydy]

don't think you'll find it in the bentley, as I'm sure its not a factory part?.
This guy sells the relay upgrade kit
https://sites.google.com/site/vanagonhe ... tart-relay" onclick="window.open(this.href);return false;

and a fitting guide
https://sites.google.com/site/vanagonhe ... all-photos" onclick="window.open(this.href);return false;
haven't seen any UK suppliers

[Ralf85]

Cheers for that mate.

[syncroandy]

Hi chap, most of us manage just fine with the starter circuit as it is, all too often folk install 'fixes' like this to workaround some other problem. Too often the 'fixes' are badly done and cause trouble in the long term, better IMO to deal with the original issue. If your ignition switch or wiring is suspect, then I'd recommended simply replacing the switch, and cleaning up all your wiring terminals as a start.

[CovKid]

If everything on the starter/charging circuit is original, consider renewing as even a relay won't solve poor cables and connectors:

http://wiki.club8090.co.uk/index.php/VW ... ain_cables" onclick="window.open(this.href);return false;

Nothing wrong with relays and lots of places they're needed but do remember that every relay added creates an additional potential for things to go wrong as there are then more connections.

In addition (and i think I've used this analogy before), fitting a relay for the ignition starter circuit when cabling isn't too good to start with is a bit like having a hose with a leak and moving the hose further away from you so you can't see the leaks.

Do some real prodding around and see how good the existing wiring/cable/connectors are before you jump straight into fitting a relay. I found there wasn't really a need for a relay once I'd done it all although no harm in doing both ofcourse.

[California Dreamin]

You can do this yourself at a fraction of the cost..

Interesting statements in their advertising by the way.

1) It will no longer have to carry the starting current to the starter solenoid. The solenoid trigger wire doesn't carry 'starting current to the solenoid' It actually carries the trigger feed to switch the solenoid .. one is around 150 amps the other under 10 amps.
2) This provides a shorter path from the battery to the starter, which ultimately provides more juice to the starter. wrong again...if the feed is taken off the starters 8mm positive post then this has to get its power from the battery, all the way back to the front of the vehicle. Also, remember that this circuit will suffer around a 2 volt drop whilst cranking which may effect the 'hold down' on the solenoid.

If you do have a hefty leisure battery, then Possibly the best idea would be to have a feed from that battery to this relay as it doesn't suffer voltage drop under cranking.

Martin

[syncroandy]

You can do this yourself at a fraction of the cost..

Wut ? Bodge his vans electrics ?

[California Dreamin]

If he has too lol.....


Martin

[CovKid]

As Martin says, the draw on the primary (trigger) part of the starter circuit is about 10amps - possibly less if the wire is in good condition. Don't forget that the starter solenoid is a relay itself.

Some fit a relay to the primary circuit to reduce the load on the ignition switch, although its rated to take it. I'm not wholly against the concept but wouldn't use one myself. It'll be sods law that the relay would fail sooner or later (or the spade terminals part company), rendering me stranded somewhere I do not want to be and more things to suss in an emergency.

My approach is try to keep the starter circuit (as a whole) as simple and as clean as possible as this makes it more reliable, less prone to trouble, and easy to carry out periodic maintenance (if any).

Having had unpleasant experiences laying in snow under other peoples Beetles, Bays and T25s trying to sort out starter problems, the only sure way to obviate trouble is replace/upgrade any ageing cables at the first opportunity and avoid where possible, any kind of crimped connectors. 90% of mine is soldered too. No connector should have strands of wire hanging out either and anything underneath should be covered (original rubber boots or black putty) to help shrug off the wet and minimise corrosion. Its the one part of a car/vehicle that needs to be done really well to offset trouble. Increasing the rating of cables helps no end.

Starters fail, part of life, but diagnosing faults becomes really easy if you keep things simple. I do know people that cut inspection hatches in the body above starter motors to make access easy from within - quite a good idea, but again, if the job is done right, one isn't really needed. If an ignition switch fails, they're cheap enough and at least you're inside replacing it.

[MidLifeCrisis]

Also, remember that this circuit will suffer around a 2 volt drop whilst cranking which may effect the 'hold down' on the solenoid.

But surely the 'original' trigger wire that goes through the ignition switch would also experience the same voltage drop? Or am I missing something?

[California Dreamin]

Indeed....the same voltage drop, the difference being the 'initial' 10amps or so will be drawn off a wacking great 200amp cable 'before' cranking starts, so the relay mod ensures good initial movement and power switching inside the solenoid but then....cranking begins and this heavy cable has to supply 120 - 150 additional amps...that is when voltage drop occurs.
Admitedly, solenoid amp draw drops from initial pull down to hold down (from 8 - 10 down to 2 - 4amps) but voltage drop from cranking could be pulling the voltage as low as 10.5 volts.
The benefit as I see it with a relay, is only with the initial pre-cranking phase where the thick starter feed will suffer little or no voltage drop compared to the original 'smaller' switching feed wire.

Martin

[bigherb]

It is a good idea to fit a starter relay. The the ignition switch has to switch over 30 amps to engage the starter and 11 amps to keep it engaged reducing the load on the ignition switch which aren't the best anyway stops the inevitable arcing of the contacts. If the relay is fitted correctly using a good quality relay and terminals it will be less trouble than any of the original components.

[Ralf85]

Cheers bigherb and thank you lloydy for the supplier. I am going down the relay track. Jay was so helpful in getting me through the US postage cost. He sent me an amended Paypal link which included the postage. Having ordered it he confirmed that it was being posted that day and said thank you. Good stuff.

[Ralf85]

Update. First, thank you lloydy for the contact details for the relay. Second thank you bigherb for the confidence boost.
The quality of the relay/wiring and standard T3 connectors provided by the supplier as well as the build of the relay is superb as well as the speed of service. With the exchange rate so favourable the part and the six day delivery proved a bargain. Tracking was provided and the guy sent me an e-mail saying 'part now despatched and thank you for the business'. Even better were the detailed instructions that came with the pack plus an additional wiring pack and instructions for those with westie conversions.

So the real test was starting the engine this morning when it was nice and cold. The starter usually struggles in the cold. No struggling today for the first time ever. Brilliant. Thanks again guys!

[lloydy]

Cool, the supplier is a good guy and a mine of info on thesamba. Glad it all worked out ok