HOW TO - hot start relay

Discussion in 'How To' started by Stan, Aug 11, 2011.

  1. hailfrank

    hailfrank Admin esq.

     
  2.  
  3. hailfrank

    hailfrank Admin esq.

     
  4. I found the biggest problem with starting was that the volts to the coil went right down when the battery was cranking the engine. Solution(eventually) a new battery and coil. But the get home fix was to connect the plus terminal on the coil to all those nice Volts in the leisure battery while it was being started. a length of wire with croc clips each end is a really useful glovebox filler !
     
  5. Top tip!
     
  6. Oh god - I forgot the important bit. You MUST disconnect the regular live feed (black wire) to the coil !!!!!!!!!! If you don't, you've just connected the starter battery to the leisure battery via the dashboard ! This not good. Once it's running don't reconnect the regular supply to the coil unless you swap it over very quickly and you know the starter battery isn't flat. The only thing the leisure battery should power is the coil, the choke heater and the fuel cut-off solenoid. It'll last for ages. Sorry, hope nobody's toasted their harness and ignition switch already . . . . .
     
  7. This is on my to do list for this weekend, just a couple of questions before i get stuck in:

    is this a one way works only, in other words if the van starts it will always start (hot or not) and the whole wiring is correct and if it doesn't work i have either followed the instructions wrong or i have a duff relay.

    probably going off thread slightly, i do not understand how the earth works and forgive my ignorance, but if i use the rock and roll bolts like on the original message says is there any way it can make the bolt live and do i have to remove the waxoyl and paint to get a good earth, if so can i paint it afterwards.

    Thanks once again
     
  8. hailfrank

    hailfrank Admin esq.

    if it starts after you've fitted it works. if not you need to check you've followed instuctions.
    it really is easy and best mod i've made to mine
     
    thetemple likes this.
  9. Going to have a go at this at the weekend. Has anyone got some pics or a description of where they mounted theirs in the engine bay, and how they routed the wires?
     
  10. Some body help i have just tried this and i will Not start then take it of and it starts am i doing something wrong im put this on a pancake motor
     
  11. one to add to the todo list
     
  12.  
  13. eek,

    just done this, my wire colours weren't exactly same on the solenoid but my ignition feed was red white (That's what was connected)

    Anyway I turn the van over but it won't shut off, keeps turning over so I've got a permanent feed into my starter I guess. Only happens after I turn the key as though to start the engine, ok in all other positions.

    Can anyone throw me a light on what I might have done wrong, I was confident it was all ok.

    PG
     
  14. Hi, I'm near Switzerland on my hols in my camper and I'm being plagued by this non hot start issue.
    I've got a relay,some wire and connectors and have seen your diagram,which I hope will be my saviour because I'm going greyer by the minute over this.
    Just a quick question really,you say pull off the original thin wire off the starter? What do I do with the old ignition wire then? Leave it on the starter?
    I'm not so mechanically minded so please bare with me.
    Thank you for any advice as I'm going to attempt to tackle it in the morning.
     
  15. Do i need to run a wire from my ignition switch off my dash is what I need to know really.
    Please help!
     
  16. the original small wire that ran from your ignition switch to the solenoid is the wire you use to "switch" the new relay, Basically instead of your ignition switch turning the starter / solenoid on its now turning on your relay which in turn puts power from the much nearer (and less likely to be high resistance) direct battery terminal on your starter.
     
  17. Ooh I have been away for a bit and only just noticed these comments sorry folks.
    first of all the wire colours I have might not be the same as yours but the wire locations will be. Our vans are 40+ years old and god knows whats been done to them so you may have to ignore colours and follow the wiring diagram instead.
    So lets try to make this easier for everyone with more detail- its always difficult writing stuff on forums like this, but I hope this full fat description will help thinks to be clearer?

    Please follow the wiring diagram , its easier to understand than my text.

    YOU MUST DISCONNECT THE BATTERY EARTH TERMINAL BEFORE YOU BEGIN!


    BUY 2 relays they are cheap enough (so you have a spare in the glove box.)

    Crawl under the van and look at the Starter Unit.
    Looking at the connections on the back you have 2 bolts with cables connected - 1 is Positive and the other is an earthing connection with braided cable that links the starter to the solenoid unit.(Leave that alone but ensure its a clean connection)

    Unscrew the 13mm nut on the solenoid (which has the thick Cable that runs from the engine bay , from the Battery Positive terminal (Usually RED) , leaving that thick cable on the bolt connector)
    Refer to the Diagram - Terminal 30 connection on the Relay and the soleniod bolt.
    Make or buy a Ring connection that fits the same bolt as the 13mm nut you just unscrewed and run a cable from The Relay Terminal 30 to the Thick Battery connector on the back of the solenoid. Now put a washer on there smear with copper grease and put the nut back on keeping the cable tight.

    Pull off the original thin wire from the ignition, this is a Spade connector all by itself on the side of the solenoid (lets call this cable Fred for reference later) which is terminal 50 in the diagram on the solenoid and plug that into (Terminal 85) on the relay instead.
    Remember this is the original weedy cable that sits alone and frankly is a weak spot on the VW design because its runs all the way from the Battery to the front of the van 50miles away at the from via your key Starter Switch and 50 miles back again from the cab and drops voltage quicker than a Mexican Power Station!

    In Freds original spade connector location on the solenoid , plug in the new cable (spade connectors both ends and red in my photo) this runs from the Relay (terminal 87 on the relay (terminal 50 on the Solenoid)) this will be the replacement feed, still from your ignition switch 50 miles away but it now goes via the relay, in so doing the Relay senses a lower voltage and activates a big voltage change at the other end hence feeding the Starter motor and spinning the engine. No voltage drop and reliable starting.

    One last thing I connected the Earth connection (terminal 86) to a suitable point on the body somewhere. I already had on the body (the Rock and roll bed bolts) but you can use the 17mm bolt on the starter if you want but anything will do, worse case drill a tiny hole in the floor and use a nut and bolt with a thick washer, cleaning up the metal first on the floor to ensure a good earth . Always smear with grease and check periodically to ensure connection remains clean and tight.

    Note:
    Should the relay fail in the future all you need to do is unplug the thin original spade connector cable (Fred for ref) from Terminal 85 on the relay and back onto its original Spade connection ( terminal 50 on the solenoid) (removing the new wire that runs from the relay from terminal 87 , which I would tape out of harms way)



    [​IMG]

    Here is the diagram fairly self explanitory.(I did'nt bother with the inline fuse )
    Cable FRED is (in this diagram only) Rd/Bl running top left to the relay (terminal 85) Remember thats your original Starter motor from the ignition switch cable , it will be any colour so ensure you find it - its the only one with a spade connection to the back of the solenoid

    After doing all this and ensuring you have checked and rechecked the wiring is correct and nothing happens then either the earth connection is duff (clean it) or the relay is faulty - happened to me) so switch relays and try again. Failing that test the relay first on a bench if you can?

    Good luck and if you still have issues please reply to this post or PM me and I will see if I can help

    Regards

    Stan
     
    Last edited: Jul 31, 2014
    hailfrank likes this.
  18. Nice one,thank you.
    Would I be right to leave the original ignition feed to the solenoid in place though,just in case the relay fails in future and I'd still have half a chance of starting it if it's not too hot?
     
    Stan likes this.
  19. if the relay fails then just take the original starter cable off the relay and put it back onto the solenoid as it was before you started.
    BUT AS STAN RIGHTLY POINTS OUT DISCONNECT THE BATTERY BEFORE DOING ANY WORK ON THE STARTER
     
    Stan likes this.
  20. Exactly right - the cable I named Fred in the description above is the original cable that runs to the solenoid from the starter switch (colour is irrelevant),before you begin any rewiring. @ johnnybegud1 if you are short on time during your holiday than any autoelectrician will be able to do this for you in 30mins if you are unsure of the process? Cant cost too much either - but please be careful you are under the petrol tank . Good luck
     

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