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Denso starter motor solenoid repair kit

22 September 2005
If you turn the key and hear a click or nothing at all, it may not be the back of the ignition key switch. The same switch and click happens when the contacts in the Denso starter motor solenoid wear out. The pic attached to this post shows how the copper ring and the copper contacts on the solenoid plunger pit and wear over time which weakens the contact.NSX Denso solenoid plunger.jpg

Just rebuilt the starter motor with a new plunger and set of copper contacts that I found on Ebay for about $13.50. The solenoid plunger is made by a Chinese company called Wai Global and is part number 66-82608. The contact set is part number 66-82776. A much better option than the $150+ for a reconditioned or new starter motor.

The rebuild itself is pretty quick, an hour and a half to get the starter motor out, repaired and back in again and you can do all the work from above the car instead of underneath on the automatic trans model. With the battery disconnected, you'll need to remove the air filter box and the small aluminum bracket that holds the filter box bolt that is closest to the front bulkhead (to avoid scratching your left forearms when removing the starter motor). Find the rubber boot that covers the starter motor power cable on top of the solenoid and undo the 12mm nut. Undo the 10mm bolt that holds the power cable on the bracket and move the power cable out of the way. There is also a small black wire with a spade connector on the top right side of the solenoid which needs removing. With a 17mm socket, find the two bolts that hold the starter motor (hold your digital camera down by the starter and take a few pics if you want to know exactly where they are, one is bottom left the other is top right). With the two starter motor bolts undone, the starter should drop down for removal.

Changing out the solenoid plunger and contacts is easy. Undo the three 7mm nuts that hold the top on the solenoid and the plunger will be exposed. Pull the plunger out and don't lose the spring. Replace the contacts one at a time as they are different shapes. I found that the copper bolt on the longer of the two contacts had some splines that bite into the contact when tightened so I had to grip the bolt and the old contact with a couple of pairs of pliers to free them from each other. A 14mm socket will undo the nut that holds each one on the solenoid housing. Take note of the order in which the various seals and washers some off and then put the new contact in. Reassemble the contact bolts and washers in the housing and make sure the contacts are flat to the plate they sit on before tightening them completely. Since one of the contact bolts had a splined head, make sure you fully tighten it so that the splines fully seat into the new contact when the nut is tightened so that the square bolt head doesn't hit the copper plunger ring when the plunger is moving in and out. Drop the new plunger in with the spring on it and make sure it isn't hanging up on the bolts etc. before it touches the contacts. Put the cap back on the solenoid with the rubber gasket in place and then drop the starter back in the car.
Good to know!

These guys provide a video showing the tear down and replacement of the contacts and plunger on a Denso starter. Note the narrator's comment that it is the contacts that fail on Denso starters. They claim the brushes and other parts are not a problem.

To the OP. Do you have a link to the Ebay site where you found the parts? I did a search on the part numbers and didn't get any Ebay hits. At $13.50, the price of 3 Starbucks Venti lattes, I might just order the parts to have them on hand - add to the collection of other stuff that I have never used!
This is helpful. I was planning to get rebuilt one from Denso. Swap it and rebuild mine. But I think at $15 I may just rebuild mine and save. Thanks for sharing
This is helpful. I was planning to get rebuilt one from Denso. Swap it and rebuild mine. But I think at $15 I may just rebuild mine and save. Thanks for sharing

I been doing this for years with the Denso starters, always works. I have never seen one fail for any other reason. ( these were used inall kinds of makes and models, including Harley, Dodge,Toyota of course. ) its a shame Honda switched to the cheaper Mitsuba's with a higher failure rate.
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