Got a 6V, 3 post Ford relay from ebay for my "74 2.0L Wired it up per the many threads on the subject on this and other boards.

My understanding of its operation is that 1 large post always has 12V (from battery) and the other 2 posts (small "S" and the other large one back to the starter) have 12V when the key is ON. Is this correct??

I'm not getting 12V at the large post that runs back to the starter. I'm thinking the Ford relay is defective.

Any thoughts from Ford relay users??

Paul

Why would you use a 6v relay on a 12v system?

Maybe a visual would help.

Click to view attachment

Click to view attachment

Click to view attachment

You won't get 12 VDC to the large post that runs back to the starter until the key is in the "Start" position. If you don't have 12 VDC with the key in that position, then the Ford Solenoid is defective or you wired it wrong

Because I read the following in an Aug. 19, '14 thread on the subject:

"I prefer the 6v Ford solenoid because it'll fire on under 5v, something that can be an advantage in a car with old wiring, a weak ignition switch, and weathered connections. I ran one on The Thunderbus for 20 years, the last 10 with a 2.4/6.

Have fun, The Cap'n"


and I thought it sounded logical.

Can I ask why your pic has 2 spade connectors??

Paul

Here's how I wired it:

- battery cable/alternator wire to large starter post and then connected to one of the large Ford relay posts.
- ignition wire that WAS on Starter spade connector to Ford relay small "S" post.
- 2nd Ford relay large post to Starter spade connector where ignition wire WAS.

Correct?

Paul

Battery cable & alternator cable to one side of the Ford solenoid. Equal size cable from the cold side of the ford solenoid to terminal on starter and smaller gauge wire from same terminal to starter solenoid spade terminal( in other words, two wires from cold side of ford solenoid to starter).

Yellow wire (normally to starter) to terminal on ford solenoid.

rock&roll

It's just a different version. Does the same thing. Your fine with that solenoid as long as it is making contact.

The 2 small terminals are for the coil. One needs power and the other one needs to go to ground. The power one is from the start circuit so it will only be on when you turn the key to start.

It's a 3 post relay, so there's only 1 small post. It's grounded through the mounting bracket.

Paul

Depending on the coil design it might need to be grounded at the other small terminal. Check for resistance from the terminal that the start feed is connected and to the mounting bracket, it might be grounded through the bracket. If not then it the 2 small terminals would be + and -. sorry if this is confusing but I looked up wiring diagrams an some aplications the 2nd terminal runs to the coil.
http://www.bing.com/images/search?q=ford+s...selectedIndex=2
Sorry if the other post is wrong, but you need pos and ground for the coil.

Any description of why you want to use a relay to run a relay would be helpful. My willingness to believe is high, my understanding is low.

The ford solenoid needs to be a grounded.

6v or 12v solenoid it doesn't matter. Yes the 6v kicks in with even less volts then the 12v, but not enough difference to matter.

Jump a wire straight from the battery to the small post, if it clicks (not hooked up) or turns the starter (hooked up) then the problem is elsewhere

There are 25+ threads on this board regarding adding a relay to the starting sequence. My understanding is that the additional relay requires less current and will reduce the load on the ignition switch (prolonging its useful life) and help in "hot start" situations..

Paul




I will do so in the AM.

Paul

I connected 12V to the Ford relay "S" post (small post) directly from battery (confirmed by test light at post) and got NOTHING --- no clicking, nothing.

Defective relay right out of the box??

Paul

Yes ......... they're made in China. Nuff said?

You could also apply 12 VDC and check for continuity between the large posts with a VOM.

I joked about this on a previous "how to wire an extra solenoid" thread - nobody got it.

Yes you are using a relay to drive another relay.
The solenoid mechanically moves the starter gear to engage AND closes contacts to provide voltage to the starter, so it IS a relay.

The starter Solenoid requires > 8 Amps to drive the mechanism to closure.
The keyed ignition switch is stressed when you turn the key and Arcs when you release it.
This causes premature wear on the ignition contacts.
The current also drops as the wiring ages and the numerous connections in the harness oxidize.

So the solution is to use a secondary relay to provide the ~9 Amps to the solenoid instead of the ignition switch.

These secondary relays only require < 0.5 Amps to engage so wont tear up the ignition contacts as quickly.
And you are not running the ~8 AMPs to the front of the car & back.

Did that also --- NO continuity. Already have it boxed to send back to the seller.

Anyone know what brand of this type relay is not China made? Or do I need to go to a Ford dealer?

Paul

Try the Ford dealer in bejing. The Chinese only send Junk parts to other countries, and with impunity I might add. They sometimes get lucky and make good parts but those never leave the country. LOL

E-Bay Motorcraft Relay

Ah, yes. But relays delivering 8 amps are fairly thick on the ground. Are we going for an antique 6 v design to help in the event of low battery?
I am working on getting around to working on adding switch on relays myself. Easier to replace than the switch. Also I got a whole bunch of them surplus. Not necessarily what I need tho.

I am afraid that for the time being . Not always, but so often I have opened a box to find a part not worth the box let alone shipping. Problem is most companies of any size are international.

The solenoid pull-in current is 35 Amps. Hold-in current is 11 Amps.
Haynes manual, page 119, bottom left.
Now you can see why the ignition switch takes such a beating on the contacts.
Tom