D17 Series IV starter solenoid

I dont know of hand any part numbers but I priced one for my series IV and agco wanted like $90.00!!!!! They most likely dont even make the part so I'm curious also about another source. Thanks for the post!! Ryan

If you don't care about correctness go to any auto parts store or eBay and get one for any mid 70's Ford for around $20 bucks give or take.

There is 2 different 4 post solenoids. The 4th wire is a ground for a continuis operated solenoid. The other 4th wire solenoid goes to coil to provide 12v to coil while starter is engauged. MACK

Yeah i would also like the part # or store you used i have 2 more series 4 that will need the same part.

Get the part number off your Delco starter and go on e-bay. I just purchased a new solenoid for my AC 175D for 15 bucks plus 7 bucks for shipping.  I try and stay as far away from AGCO as I can...   

Its like anything else.  You get what you pay for. A $20. relay is just what it is. It probably won't last to long in service.  For that type of application, you need a HD relay that will kick in, and quickly kick out and stay in service a long time. I have HD relays on the shelf for the "D" series Tractors. They are HD, and they are not twenty bucks either. A good heavy relay will run in the range of $45.-$90 bucks depending on its application, but its a one purchase deal when you buy a good one. The relays I have I believe run around $60. bucks if I remember correctly. Its been a while since I sold one. Just the wieght alone between the twenty dollar unit and the sixty dollar unit will explain the difference. Drop me an e-mail if interested.. We have anything electrical for the Tractors in stock...

The NAPA counterman quoted an Echlin ST80 (continuous duty), steel body like original,  about $60.
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I find the 4-termnial ST80 does NOT have the small terminals marked as "S" and "I". One small terminal has to be grounded for it to work with the starter circuit and the ignition bypass feature would be lost.

When the original Delco Remy solenoid is grounded and 12v is applied to the "S" terminal, the coil engages to power the starter and the "I" terminal provides 12v to the coil, bypassing the ignition resistor.


Edited by DEP5 - 31 Jan 2012 at 11:32am

Ancient thread but hoping for assistance with a similar issue. Thanks to the advice from previous replies I've got the right part in but the wiring isn't quite right.

AC 170 starter solenoid wiring

I am far from a mechanic and trying to figure out what's wrong. I took over repairs from my uncle who has fallen ill. Right now the tractor starts but the starter motor continues to run after ignition. I've tried different combinations but nothing is resolving the issue.

Total hail Mary but hoping someone can lend an eye. Unfortunately, I do not have a picture of the original wiring.

Black in picture was added to ground to frame.

Bds86 wrote: Ancient thread but hoping for assistance with a similar issue. Thanks to the advice from previous replies I've got the right part in but the wiring isn't quite right. AC 170 starter solenoid wiring I am far from a mechanic and trying to figure out what's wrong. I took over repairs from my uncle who has fallen ill. Right now the tractor starts but the starter motor continues to run after ignition. I've tried different combinations but nothing is resolving the issue. Total hail Mary but hoping someone can lend an eye. Unfortunately, I do not have a picture of the original wiring. Black in picture was added to ground to frame.

Thank you for the feedback! It's definitely push button start and starter stays engaged.

Sorry about the large picture. Not sure why it didn't crop. I've tried 2 NAPA solenoids as others discussed here. ST80 had the same issue so I've tried ST67(in picture) which has the I and S labeled posts. Both small wires are on one post and the other needs a ground wire back to the tab mount screw or frame. I was also under the impression it grounds through the tabs.Without that wire theres power to the key but the ignition button does nothing.

I was just told this morning that the solenoid issue happened shortly after replacing the battery but I'm not sure how a battery could've caused an issue? Might have shorted something.

If I bypass the wire spliced to the small post to the other side of the large solenoid, it fires and starter disengages but I have to disconnect that bypass to kill the engine.

All very confusing to me and either the part is totally wrong and I'll order off Agco, or it's going to take some wire tracing.

Wired incorrectly. Push button starter wire to "S" on the relay.  Double wire connection on the resister goes to the "I" terminal on the relay and also goes to the coil on the engine. Whatever that black wire is get rid of it.