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This is my second post on the topic but hopefully a bit more descriptive.
Bosch starters use a electromagnetic solenoid for activating the starter mechanism. Like any electromagnet when they get hot the electromagnetic force is substantially reduced. Often to the point the solenoid can't pull hard enough to activate the starter. ALL Bosch starters suffer from this problem, particularly when old and always when installed on an automatic transmission (right under the exhaust manifold, a brilliant piece of engineering)
Symptom: You turn the key and nothing happens. Nothing. Not even a click. The voltmeter does however show you sucking major current.
You can wait for the starter to cool off (about an hour usually) or you can get more current to the solenoid so it can finally develop enough force to run the starter. Although the wiring is fine it's not heavy enough to pass the current required by the solenoid when hot.
Solution #1 get a long screwdriver and short from the main starter terminal to the solenoid terminal. Works great. Makes lots of sparks. Destroys screwdrivers. Sometimes cars.
Solution #2 Get a new solenoid/starter. Doesn't always solve the problem.
Solution # 3 Wire in a relay that's triggered by the keyswitch and has current on a heavy wire direct from the battery.
Bosch makes a relay kit just for this. Seems it's been a problem since VW Beetles roamed the earth. It's called the WR1. In many peoples oprion it's not heavy enough for the job. Solenoids can desire up to 30 amps of current to work. Which makes a small relay a part ready to melt, short out and possibly engage the starter and not let it release. Not good. We need a better relay.
Here's what I did. Went to AutoZone and got what is known around the world as a Ford starter relay. Design dates back to the 30's I think when they used to actually pass the current to the starter thru one of these. So it's kinda heavy duty. The part number is Duralast F496. Cost about $10.
You'll need to make a short wire from the keyswitch wire to the relay post. (S) Another longer wire from the battery terminal to the big post (either one) and another to go from the other big relay post to the solenoid terminal. All of the connectors are available at Walmart/Autozone etc. I always install such relays close to the starter so the current path is short. But realistically you could mount it on the firewall or fender and be ok.
Here's the relay

Here's how the wires attach to it.

I installed it to a tab on the tranny housing since the bracket is the ground of the circuit for this relay.

Here's a closeup of how it's nestled in there.


Here's a wiring diagram I found in another forum but it's nicely made. Note the diagram shows a 15A fuse but that may be too small. Start with 15 and work your way up to a 30A. My hookup uses no fuse at all but I don't really recommend that for others.

Enjoy!!
Have a beer to celebrate!


Modified by Moljinar at 6:58 PM 5-4-2006


Modified by Moljinar at 10:25 AM 5-19-2006
 

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Re: Starter relay for heatsoak problems (Moljinar)

Excellent!!
Added to the FAQ!! http://****************.com/smile/emthup.gif

<edit> copy pasted the following in, got tired adding it to threads linking back here.
---

.........the heat soak relay fix is not unique to automatics. It is far more commonly needed on automatics. Here's a link to Bentley forums, the three jpgs linked in the 2nd post are the factory bulletin on the topic. This factory version of the fix uses a Bosch or other Euro relay and several other VW specific terminals and a terminal block.
http://tech.bentleypublishers....art=0
The "problem" and cure are actually as old as Bosch starters. I have stories from the 6V days.
Anyway, Moljinar's write up uses a Ford relay. The Ford unit is a far more robust and dependable relay, it's perfectly suited to this application. The Ford part is definitely the best to use. Can't expect VW to recommend a brand "F" part, can we?..........
____________________________

</edit>





Modified by tolusina at 12:21 AM 4-8-2007
 

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Re: Starter relay for heatsoak problems (Moljinar)

The autozone part works great, but if you can find the actual ford relay it has recessed terminals. The terminals actually sit down in a hole and there is a slot where the wires run to the terminals. Keeps the odd wrench from shorting against the terminals when working on your car. Any ford truck or van up to 1986 has them so look for it next salvage yard trip.
The fiat x/19 had the same problem, and if you have the x/19 your cabby starter will fit it. (oops now everyone knows Im old)
 

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Re: Starter relay for heatsoak problems (Moljinar)

This post is good save for the 90'ish Automatic cabs.
There is another relay in the system, that is located Behind the Knee-bar.
That is VW's attempt at a heat soak relay. That is also a cause of intermittant No-start..Cold or HOT though...
See:
http://www.toplessrabbit.com/f...=1667
Between the two, we got it covered for all years.
 

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Re: Starter relay for heatsoak problems (theoldkid)

so i have a pretty much brand new starter ( bougth and installed last summer) only driven in the summers and late springs/ fall. so its new
But i just installed a 270 cam, and after starting once, letting it run, and esp int he hot weather ( even when tis been sitting a longg time), it wont start ont he first key turn, sometimes not even ont eh second. it just makes a whinning noise.
is this heat soak??? or is my starter not strong enough to turn the new cam when its hot?
 

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Re: Starter relay for heatsoak problems (dubaholic92)

Is it automatic? from your tag line it says 3 speed of fury...
If it is a 90ish Auto, then you have the other problem possibly.. That and possibly your starter is mis-aligned.. When you installed it did you use all 3 bolts?
 

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Re: Starter relay for heatsoak problems (briano1234)

Quote, originally posted by briano1234 »
Is it automatic? from your tag line it says 3 speed of fury...
If it is a 90ish Auto, then you have the other problem possibly.. That and possibly your starter is mis-aligned.. When you installed it did you use all 3 bolts?
http://mk1dubs.com/modules.php...=1920

the 3 speeds of fury is sarcasm yes its auto, a 92. unfortunately i didnt install the new starter so im not sure on the bolts, but it worked beautifully until the cam went in. and what is the other problem?
 

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Re: Starter relay for heatsoak problems (dubaholic92)

The other problem in that VW designed their own version of the heat soak relay.
But they tied half of it in to the Digifant control system.
The link was the location of the relay and the resolution of a no start hot or cold issue.

If the starter is missing one of the bolts probably the top one then it could be out of position so that the bendix isn't engaging the fly wheel.
I don't think your cam has anything to do with the issue, it is just co-inky dink.
 

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FV-QR

That the starter motor spins says it's not an electrical issue.
The starter is either loose and falling off, or it's shot. You're going to have to get under the car and put socket wrenches on the bolts to find out if they are loose.
 

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Re: FV-QR (dennis2society)

well it turns out that it wasn't my starter... it was the nutral switch in the shift console assembly that wasn't all the way clicked in, I have to jiggle the stick thing to get my car to start sometimes..... oh well the hunt is on for a shift console asembly
 

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Re: Starter relay for heatsoak problems (Moljinar)

me. 93 cabriolet auto. having heatsoak prob. installed a new starter starts and works great untill hot. went out and bought wires and the ford starter relay pictured in this post. mounted to inner fender by airbox. ran separate ground from tab on ford solenoid to the battery negative and its bare metal under the bracket on inner fender area, ran all wires exactly the same. car doesn't start the new solenoid/relay clicks. have full voltage at everything. am i missing something? if i take everything off and hook up starter in the factory manner the car starts right up? really wanted to do this since after it is hot car wont restart and i hate waiting for hrs or leaving the car running. help!!
 

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Re: Starter relay for heatsoak problems (lotus4)


There is the wire you spice in to. Take the starter side to a big lug on the relay. Take the switch side to one of the other smaller lugs.
Take the other big lug to the Positive battery and remove the ground. (It grounds itself via the frame mounting point... if you placed a ground on the other little lug I am thinking it wont work if I remember the first time I connected mine up.).
 

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Re: Starter relay for heatsoak problems (briano1234)

fixed it! wasn't the ground. the other wire from big post on the new solenoid wasn't contacting properly to the original post on solenoid of starter. all better now. this was an excellent writeup. only thing i have left to do is put some insulation on the wire to the starter so it doesn't burn up from the heat under there! thanks all the vortex rules
 

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Re: Starter relay for heatsoak problems (Moljinar)

I have a 1997 Jetta GT 5 speed. that seems to have this heat soak issue. Trying the fix detailed above, but not sure that I am connecting the relay wires correctly to the starter. When I connect to the Blue wire, the starter engages soon as I turn the key from off position. It doesn't wait till I get to the Start position. I
The starter only turns for a second, and the engine doesn't start. Don't want to do any damage before getting clarification.
I'm using the relay method described in the Eric Diaz drawing, but am confused because I do not have the wire with the Yellow sheeth.
Any help is appreciated, since I've been having to search for sloped parking spaces for too long. Only vw owners can appreciate seeing me push start this thing like fred flintstone.
http://s494.photobucket.com/al...r.jpg


Modified by weybs at 6:07 PM 11-16-2008


Modified by weybs at 6:08 PM 11-16-2008
 
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