Starter relay for heatsoak problems

[Moljinar]

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

[tolusina]

Excellent!!

Added to the FAQ!!

<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

[Moljinar]

Quote, originally posted by tolusina »

Excellent!! Added to the FAQ!!

Thanks! I titled it so it'd popup in a search on the topic.

[itschuck2c]

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)

[NJ_Cipher]

Where are you guys terminating your alternator cable???

[briano1234]

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.

[theoldkid]

Thank you for your (as usual) great write-up. That will be included as one of my projects next Spring.

Happy Thanksgiving, everyone !!

[dubaholic92]

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?

[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

[dubaholic92]

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?

[briano1234]

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.

[dubaholic92]

hm so your saying mine shouldnt have a hot start issue... its either a missing bolt, or something with that relay that u sent the link to.

[tolusina]

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.

[dennis2society]

subscribed, I think this is happening to my caddy lately.....

[sweetpea2127]

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

[lotus4]

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!!

[briano1234]

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.).

[lotus4]

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

[weybs]

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

[Moljinar]

I'd check your grounds first. The fact it turns for a second means it should keep turning. A heat soaked starter usually won't turn at all. Go over all your connections to make sure they're good.
...0ran..

[93karmencabby]

OK I understand all you have posted , however 1 Question , I have noticed that on my stock solenoid,( Automatic tranny behind exaust manifold) that the big terminal closest to manifold seems slightly loose and if I turn it counter clockwise till it feels tight (not much movement) it will usally start, Now will just adding the relay solve my problem or should I replace the solenoid as well? Also would this same thing work on my 1974 Harley sportster with a similar type of solenoid setup?

[briano1234]

If the terminal is loose? is that the Spad terminal or the nutted one?

If it is the nutted one tighten it all the way up.

The how to change your starter (automatic) is in my FAQ on page 3.

[93karmencabby]

Hmmm well, the nut and wire seem tight , it seems to be the whole terminal thats moving slightly, also I have noticed that the heat shiel is gone, I got another one from a bone yard but can't seem to figure what it attaches to, and you FAQ page is where? Pictures are worth a 100 words , if I can see pics and diagrams I cana figure the rest out.

[briano1234]

How to remove your automatic starter.

http://www.the152.com/modules....=3110

The faq's are the very first post thread in the forum.

Official Cabrio/Cabriolet FAQ

As in Frequently Asked Questions.

The heat shield on a automatic, is held in place by the lower starter mounting bolt and the to "Y" shaped pieces that attach to the rear of the starter by 2 10mmnuts, and the sheet tin is attached to that by 3 10mm bolts.

If the stud is twisting then you either need to tighten it fully, or replace the starter. You may ne able to take it to a Auto Electrical place and they can rebuild it for you cheaper than you can buy new.

[93karmencabby]

Thanks man , the pictures explain alot, apparrently I am missing the y shaped brackets for the heatshield, but from the pics I can fab something up., also I did read your 93 under the Knee bar article and have locate dthat as well, thanks again. paul

[93karmencabby]

Hey in your article you say f496 but in your average joe wirring diagram, you show an f492 , my local auto zone only had a f492 in stock is there a differance or will either work?

[briano1234]

that is the difference in where the large terminals are located.....

One has them on opposing sides.
The other is about 1/2 inch from each other... (which makes it easy to pick if you need to test it.)

[93karmencabby]

Thats what I figured Thanks

[Nart]

Great work !!!! thx so much

[Moljinar]

Had one of each installed at different times. Didn't realize my pics were different.

A starter relay is a starter relay. Only the terminals move around.

[dubpunk13x]

I used this awhile back and it worked great. Starts every time now. Thanks for the help.

[YJSAABMAN]

Swapping my cabby form auto to stick, but swapped this setup from my car into a friend's Scirocco.

[AutoEtienneAigner]

Related to this, I also have a dead car now that has this same problem. It doesnt seem to be the whole solenoid but just the "guts" that seem to be loose inside. Tried tightening up both terminals (under and on top-of the power cables) but still loose. The car only clicks at the starter relay now when I try to start the car. Any thoughts would be great! Thanks in advance!

[briano1234]

If you haven't installed the heat soak relay then do so now.

Key switch on.
Car in park.
Parking brake on.

Look for the red wire in the picture.

Jumper 12V+dc with a heavy gauge wire directly to the battery. If the starter dosen't engage, then you have a wonky starter and it needs to be replaced.

how to replace it:
http://www.the152.com/modules....matic

[AutoEtienneAigner]

Ok, I plan on giving this a try but I thought it would also be worth noting that a couple days ago before it completely died on me it was having intermittent charging issues. Cruising down the freeway my volts went from 12+v to 10 then back up to 12. Later that day it went back to 10 then down to nothing. Tried to jump start the car afterwards only to get a single click from the starter relay under the dash, nothing else. No crank, only a click. What does this mean?