I have a Caterpillar 320c excavator. 5000 ish hours. Bought it new. I replaced the original starter back in winter. (Unless some of my guys replaced the original without my knowledge in past). I bought a ITR aftermarket starter. Installed it. Starter did well. But if I had a water in fuel issue and tried to restart, sometimes it would be weak or glitchy. I let the machine sit a month or two and now the starter has failed. I removed it. I can see some corrosion, and black spots on solenoid. Some melted rubber wire insulation between solenoid hot wire and main starter motor wire. This seems to have happened between the winter and now july. That’s pretty fast. so, I have no ordered a COSTEX starter. the COSTEX/CTP starter looks the same. Looks good. BUT….it has an extra little solenoid flopping on top. It has two screws on side that looks to be where I should mount the little baby solenoid. Looks as though I can choose to bolt the baby solenoid on top or side. Starter main frame near nose cone has the option of top or side mount. this baby solenoid is wired to the main solenoid already. In the box. My original starter did not have this solenoid. The ITR starter I replaced it with did not have this baby solenoid. But NOW this COSTEX starter has the baby solenoid. what is it for? Is the starter I purchase a universal application for multiple excavators with different applications? Maybe this baby solenoid is to turn on a heat strip or glow plug when hitting the switch? If so, that would not be giving the glow plugs ample time to do their job. I noticed when I pulled up cat 320c starters on eBay, many show this little baby solenoid. should I run my switch wire to this baby solenoid even though the original starter did not have this? Is this an upgrade? Any tips? Maybe this baby solenoid eliminates a problem with the original starter design? Takes the load off the switch wire? I will attach some comparison pics of original starter vs. COSTEX starter. Thanks
It's an upgrade. Trigger wire triggers baby relay, in turn, battery 24v goes thru baby relay to main solenoid. Solenoid on starter now gets juice from big red battery wire, rather than the circuitous route of battery to relay box to solenoid. It's a must do for starter long term life. Yes, it takes the load off the original crank wire circuit.
I would not say its a must do, but if you can fit the starter ok with it on i would use it. It does eliminate a lot of problems when cranking in cold conditions and when battery's are marginal. If you choose not to use it be careful to check the primary current draw of the new solenoid as it may be higher to the old one. It just looks a little weird because the solenoid they have there is large for the starter and they are normally a little smaller but it will be fine.
Thanks for the reply. - so, I installed the starter. I tried to put the switch wire on the baby solenoid switch connection. I tried both sides. It would not power the baby solenoid to click on the big solenoid. But, if I removed the power wire from the baby solenoid that goes to the big solenoid and hooked the switch wire to the by solenoid (original switch wire connection) it works and cranked. I’m not sure why it won’t force the baby solenoid to work. It makes no sense unless the switch wire is coming from some type of “smart” connection. Weird. It won’t even fire a small amount of voltage in the baby relay with a test light. It’s as if their is some type of module smart system that is sensing a difference.
Thanks for the reply. - so, I installed the starter. I tried to put the switch wire on the baby solenoid switch connection. I tried both sides. It would not power the baby solenoid to click on the big solenoid. But, if I removed the power wire from the baby solenoid that goes to the big solenoid and hooked the switch wire to the big solenoid (original switch wire connection) it works and cranked. I’m not sure why it won’t force the baby solenoid to work. It makes no sense unless the switch wire is coming from some type of “smart” connection. Weird. It won’t even fire a small amount of voltage in the baby relay with a test light. It’s as if their is some type of module smart system that is sensing a difference.