1988 RD690S Solenoid ?

[Casper1988]

I am having some electrical gremlins in my Mack. Volt meter is sporadic and also the Dynatard stops working at the same time. I have checked the fuse block, ignition switch, battery grounds, fuses, I changed the solenoid under the dash by the fuse panel and it solved my issue but the metal solenoid is getting pretty hot. Do they run hot or do I have resistance somewhere else. Could my Alternator be putting out to much?. I'm not all that competent on electrical. Thanks, any thoughts would be appreciated. Need to move wood during mud season but don't want to melt anything. 

[Mackpro]

All the ones I have ever seen get hot , really hot. The original ones were good but then Mack changed suppliers and the quality went down hill. I think they went through 4-5 different suppliers/styles before the ones they sell now. I remember changing them out once a month till we finally got some better ones. 

[fjh]

They run hot! If you replace this with a constant duty cole hersey It will work with a few mods! If your lucky enough to get a hold of the old silver bullet relay you'll be laughing PAI may still carry it! don't accept the plastic bacolite one if they offer it to you absolute junk! 

Edited March 17, 2022 by fjh

[Casper1988]

Ok, I've been checking grounds and any connections. Spent hrs yesterday looking. I have a metal one, seems crazy it would run this hot but thanks for your answers.

[Casper1988]

On 3/17/2022 at 9:35 AM, Mackpro said:

All the ones I have ever seen get hot , really hot. The original ones were good but then Mack changed suppliers and the quality went down hill. I think they went through 4-5 different suppliers/styles before the ones they sell now. I remember changing them out once a month till we finally got some better ones. 

What is the amperage I'm looking for, 100?, or more. Thanks. 63$ at Mack shop, 33$ for a metal Cole jersey at the auto store.

[Mackpro]

Not sure on the amperage but make sure it’s a constant voltage one and not a Ford tractor starter solenoid like I’ve seen a lot of people try to use, they don’t last a day.