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TL150 engine preheat light glowing while running

Stephen Doyle

Member
Joined
Oct 26, 2022
Messages
16
Location
Pike, MO
When the key is turned to left the preheat light doesn’t come on but the battery light blinks. Turn to right and machine starts ok. Not sure of the history of machine to compare how it used to start. Seems sluggish like battery’s low. By the time I turned around to check smoke in exhaust it’s already cleared up so that doesn’t seem to be an issue I pulled the cab and a few other covers back today and cleaned out the debris and did general inspections. When I pulled the relay cover back i pretty much found what Mccall said would be back there. Some of the fasteners were missing so wasn’t too surprised to find so much dirt. cleaned everything best I could and removed one of the big relays and pulled it apart to see what it looked like. Everything looked surprisingly good and I didn’t entirely know what the “cold solder joint” would look like so I took a picture of it. I expected a solder joint to be cracked or show sign of burning? There’s one spot in the upper left of one of solder joints that looks suspect but I think it’s just flux and dirt. reinstalled it and replaced all the missing fasteners and put everything back together. I only did the one relay. It has a little suspect area but also looks good to me so I’m attaching a picture so McCall and others can comment.
Afterward the machine started up fine and the light didn’t come on. Haven’t lowered cab or tested machine but still not sure if the preheat is even working. I did locate the glow timer and by visual inspection it looked alright. While I was in there I verified the alternator belt was still tight as it was loose last time I Inspected it. What a relief the belt was tight because it was a sob getting it there last time.
 
Last edited:

skata

Senior Member
Joined
May 10, 2007
Messages
1,541
Location
midwest
Yeah just get a solder iron and re melt the solder. I couldn't see any obvious cracks on mine, but after solder, problem solved.
While you got the cab up, put a test light or volt meter on the glow plugs, then cycle key to see if it turns on, and how long. Turn key left and hold and see how long it stays on
 

Stephen Doyle

Member
Joined
Oct 26, 2022
Messages
16
Location
Pike, MO
Yeah just get a solder iron and re melt the solder. I couldn't see any obvious cracks on mine, but after solder, problem solved.
While you got the cab up, put a test light or volt meter on the glow plugs, then cycle key to see if it turns on, and how long. Turn key left and hold and see how long it stays on
 

Stephen Doyle

Member
Joined
Oct 26, 2022
Messages
16
Location
Pike, MO
I do plan to reflow all the solder joints and do as you suggested with test light. That’s simple and effective. Not sure why I didn’t think of that while the cab was up. Spent a ton of time just cleaning debris out of machine and taking care of more pressing issues. Ran out of time and had to button her up. Thanks for your input and Hope your TL140 doing better.
 

Stephen Doyle

Member
Joined
Oct 26, 2022
Messages
16
Location
Pike, MO
Tha
These are broken solder due to heat cycling and the manufacturing process is inferior.
View attachment 271146
You can reflow the solder and they'll be better than new, or just replace them and kick the can down road, as the replacements are manufactured the same way.

Here's a link describing it.
http://www.electronicsandyou.com/blog/cold-solder-joint.html#:~:text=Cold joints increase the solder,the board in that case.
That’s a really thorough article on cold solder joints. It’s a bit dry and technical and I’m gonna finish over a couple sessions. Thanks for sharing that. Next week I’m gonna pop those relays out and reflow all the joints that look suspect. After reading that article I see there was a couple spots that need attention on the one relay I did inspect and I’ll do all three at that time.
It was Apparent the cab hadn’t been lifted in awhile as it was filthy in there so spent most my time cleaning machine and assessing and addressing other issues. The issues that concern me most are the whining in the pump sound and the ticking in exhaust. I put a stethoscope on exhaust tick and found it loudest right around the turbo but didn’t see any obvious carbon footprint from exhaust leak. Have you seen this pattern in any of your turbo Yanmars?
 

heymccall

Senior Member
Joined
Feb 19, 2007
Messages
5,349
Location
White Oak, Pa
All my TL150 machines have a distinct, moderately loud, whine. Since new. Almost sounds abnormal, but it is intrinsic to them. And, yes, it sounds like a gear pump whining.
 

Stephen Doyle

Member
Joined
Oct 26, 2022
Messages
16
Location
Pike, MO
All my TL150 machines have a distinct, moderately loud, whine. Since new. Almost sounds abnormal, but it is intrinsic to them. And, yes, it sounds like a gear pump whining.
Whoohoo! One less thing I’m gonna worry about! Now can worry more about that exhaust tick sound coming from turbo or near it…
 
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