Starter Relays, I recommend them on all cars now Options

[John]

This thread is real interesting. I have never had an issue other than with a bad starter or starter solenoid. Once we went through several ignition switches with the DE car until we got a good one, but that was it. Never put a relay on the starter solenoid.

I have always been under the impression that the starter solenoid WAS a giant relay that took all the major current of the starter. I have replaced starter solenoids, but the last one I replaced was years ago.

The solenoid throws the sprag out into the flywheel teeth and once fully out, the primary contact closes which powers the starter directly fed from the battery. How many amps does the starter solenoid draw? I wouldn't imagine it is too much for a switch.

Not trying to start anything (no pun intended), and I have read about this "fix" in the past, but never resorted to it. I do know that Porsche in it's infinite wisdom has taxed electrical switches in several instances (headlight switch comes to mind), so I wouldn't put it past them to have a large draw on a set of switch contacts being the root cause of switch failure (ever seen the high beam switch contacts in a 911?). Porsche certainly wasn't fond of over design of their electrical systems.

They did at least follow a common color scheme that has proven beneficial on these old air cooled cars, and in many instances, they did run ground wires in a lot of places where other manufacturers simply scrape paint off with a screw in order to ground a circuit.

I suppose the starter solenoid relay fix is a lot more common than I ever had thought. I still say clean your connections and grounds, but I suppose as a last course of action, I do like the clean look of the small relay either tucked into the eng. comp. relay board or directly attached to the solenoid.

[Tom]

Initial current thru the ignition switch is 35 amps, goes down as the holding relay takes over most of the current for the starter solenoid. This is per the Haynes manual.
Tom

[rhodyguy]

tom, if its a liability issue don't bother with the remote start feature.

[Mark Henry]

This thread is real interesting. I have never had an issue other than with a bad starter or starter solenoid. Once we went through several ignition switches with the DE car until we got a good one, but that was it. Never put a relay on the starter solenoid.

I have always been under the impression that the starter solenoid WAS a giant relay that took all the major current of the starter. I have replaced starter solenoids, but the last one I replaced was years ago.

The solenoid throws the sprag out into the flywheel teeth and once fully out, the primary contact closes which powers the starter directly fed from the battery. How many amps does the starter solenoid draw? I wouldn't imagine it is too much for a switch.

Not trying to start anything (no pun intended), and I have read about this "fix" in the past, but never resorted to it. I do know that Porsche in it's infinite wisdom has taxed electrical switches in several instances (headlight switch comes to mind), so I wouldn't put it past them to have a large draw on a set of switch contacts being the root cause of switch failure (ever seen the high beam switch contacts in a 911?). Porsche certainly wasn't fond of over design of their electrical systems.

They did at least follow a common color scheme that has proven beneficial on these old air cooled cars, and in many instances, they did run ground wires in a lot of places where other manufacturers simply scrape paint off with a screw in order to ground a circuit.

I suppose the starter solenoid relay fix is a lot more common than I ever had thought. I still say clean your connections and grounds, but I suppose as a last course of action, I do like the clean look of the small relay either tucked into the eng. comp. relay board or directly attached to the solenoid.

Since I started doing the Ford relay fix back in the late 80's it been common knowledge that the Bosch solenoid takes a minimum 9 volts to kick it, where as a Ford solenoid only take 3 volts.
I did not "invent" this, I first heard of the fix from Gene Berg although he didn't "invent" this fix either.

Sorry I've always chuckled at the blowhards that tell you to replace (hack) wiring and switches, spends hours chasing grounds, etc. I have never once cut into a factory wiring harness (other than repair other PO's hacks) or replaced an ignition switch (and now these switches are burning out). The solenoid works every time if it's just a resistance issue and never took more than a 1/2 hour to install.

[Tom]

Mark henry,
I think you have AMPS and VOLTS mixed up. The Bosch solenoid takes a minimum of 9 volts to operate at initial pull-in of 35 amps. After the internal contacts close the hold-in circuit, the amps fall off to about 11 amps.
Tom

[MartyYeoman]

I've had one installed in a similar location for about 10 years now.
Hasn't failed yet. (IMG:style_emoticons/default/smilie_pokal.gif)

[andys]

To rig up a non-Ford relay, it should be rated in the 40 amp range, correct?

Andys

[ClayPerrine]

I just use a high torque, gear drive starter. They don't pull the draw in amps that the stock bosch starter does, they turn faster, and they never suffer the hot start issue.

[Drums66]

I just use a high torque, gear drive starter. They don't pull the draw in amps that the stock bosch starter does, they turn faster, and they never suffer the hot start issue.

...."Thankyou"(and the beat goes on!) (IMG:style_emoticons/default/idea.gif)
(IMG:style_emoticons/default/bye1.gif)

[dfelz]

Mark, or anyone else please tell me which numbers go where!!

Thanks!

(IMG:http://www.914world.com/bbs2/uploads_offsite/i1293.photobucket.com-14538-1384410071.1.jpg)

[type47]

30 and 87 is the circuit that you want to supply power to. One terminal (30 or 87) will be connected to the starter solenoid and the other to +12 V (starter terminal from battery). 85 and 86 is the control of the relay circuit. When not energized, circuit is open. Connect either 85 or 86 to the wire from the ignition switch (likely to be yellow with female spade connector), the other terminal to ground. When the key is turned to start, the control circuit closes the relay and that circuit provides power to the starter solenoid.

Here's a "Ford" relay with terminals/connectors:

the spade connector to solenoid is a female connector and the spade connector to ignition switch is a male connector. All the ring terminals in the above diagram (connections on the relay terminals) will be replaced with female spade for your relay.
Would you detail manufacturer and PN of your relay?

[Mark Henry]

Mark henry,
I think you have AMPS and VOLTS mixed up. The Bosch solenoid takes a minimum of 9 volts to operate at initial pull-in of 35 amps. After the internal contacts close the hold-in circuit, the amps fall off to about 11 amps.
Tom

Yep sorry, I was in a rush out the door yesterday and never proofread my post.

[dfelz]

30 and 87 is the circuit that you want to supply power to. One terminal (30 or 87) will be connected to the starter solenoid and the other to +12 V (starter terminal from battery). 85 and 86 is the control of the relay circuit. When not energized, circuit is open. Connect either 85 or 86 to the wire from the ignition switch (likely to be yellow with female spade connector), the other terminal to ground. When the key is turned to start, the control circuit closes the relay and that circuit provides power to the starter solenoid.

Here's a "Ford" relay with terminals/connectors:

the spade connector to solenoid is a female connector and the spade connector to ignition switch is a male connector. All the ring terminals in the above diagram (connections on the relay terminals) will be replaced with female spade for your relay.
Would you detail manufacturer and PN of your relay?

Awesome, thanks for the run down.

I guess i should have asked this earlier, but, if i have an IMI-101 hi-torque starter, is a 30A relay big enough?

[ripper911]

I've had one of these on my car for years. Definitely cheap insurance to make sure the car starts, but you have to buy blade type fuses (IMG:style_emoticons/default/dry.gif) .

Hot start kit link

[Mark Henry]

IMHO the Ghia horn relay is a POS for this app.
I replaced 2 horn relays with ford units this summer. I think I still have a brand new Ghia horn relay sitting on my scrap pile.

[worn]

I've been meaning to post this for awhile and Andyrew's recent starter thread inspired me. I used to recommend against a relay at the starter because it was always known as a 'hot start' relay, and hot start issues can be a sign of a wearing starter. So I considered the relay to be a baind-aid to avoid have to really fix the problem - a bad starter.

Jamie (JRust) was having some ignition switch issues and I started to rethink my position on the starter relay. I realized that the crappy reproduction ignition switches that are available now are prone to failure from having too much current pushed through them. They simply aren't built with enough focus on quality to stand up to the way Porsche/VW designed the starting system.

So now I recommend a starter relay on all cars in order to avoid undue stress on either old, tired factory ignition switches or crappy reproduction switches. This can be any 30A or larger relay and Bosch sells a starer relay kit, but I didn't like some of the choices they made, especially because it's sold as a universal kit, which means it doesn't fit nicely on anything. So I put together my own kit designed specifically for our cars. I also found a relay that has a fuse built in, rather than a separate unit.

A starter relay can be made with pieces available from your FLAPS, but for those of you who don't feel like going that route, I've made a few of my setup available for sale. This thread is more about sharing information though, so I'll exclude the details here.

That is a nice setup Mark. BTW, we will be traveling the same route. Me Seattle to Wisconsin and you to Michigan. Offer of help still stands.

I bought one of the Ford tractor relays and it seemed really beefy. So I checked the resistance - about an ohm. So the poor switch would be running 12 amps to run it, supposedly reducing the current?!

I checked a relay similar to yours. Just a 30 amp relay I had lying around. 70 ohms. So that would be a far better solution. Just thought I would add this because I bought the tractor relay based on some of the posts in the forum, and then came to the conclusion that it isn't a good match.

[Geezer914]

You don't need a ground unless the relay is isolated from the body.

[jimkelly]

so the ford solenoid has a much bigger load than a mcmark style relay? good to know as I was leaning ford too. thanks : )

--below/above --

"That is a nice setup Mark. BTW, we will be traveling the same route. Me Seattle to Wisconsin and you to Michigan. Offer of help still stands.

I bought one of the Ford tractor relays and it seemed really beefy. So I checked the resistance - about an ohm. So the poor switch would be running 12 amps to run it, supposedly reducing the current?!

I checked a relay similar to yours. Just a 30 amp relay I had lying around. 70 ohms. So that would be a far better solution. Just thought I would add this because I bought the tractor relay based on some of the posts in the forum, and then came to the conclusion that it isn't a good match."