mrmamiller
Petty Officer 2nd Class
- Joined
- Mar 7, 2011
- Messages
- 167
While researching things that may be causing my heating/cooling problems (1986 Johnson 110HP), I find that there are two different Sierra part numbers which suppliers use as being the correct part number. I believe some of this was due to a misprint in the Sierra catalog during several years. The most current (2012) Sierra number is 18-3543. There are a multitude of suppliers that are specifying the 18-3553 as being the correct thermostat (as may have been shown in certain year Sierra catalogs). My question is, what is the difference between the two and could it contribute to problems if the wrong one is used? Can someone tell me the difference between the two? My repair shop Service Order shows that they used a part number 5005440, but I am sure that they are just using the original factory number and who knows what t'stat they actually used. Thank you.