Engine alarms on a 2009 Merc 5.0L TKS

badrano

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I looked at a 2005 Chap 204 SSi with a 2009 Merc 5.0 TKS. Had a mechanic look over things and he made a note that the lower unit oil lube reservoir was a little low and seemed surprised that there was no alarm sounding.

After the fact, I realized that when the broker rep went to start the engine, there was no alarm sound when the key was in the ON position but the engine had not been started yet. When the mechanic started the engine, he didn't make any comment about the lack of alarm when the key was ON but engine not running.

I've done some searching on this topic and I've seen a couple of different responses.
- There's a delay in the alarm to give time to start the engine
- There should be alarm the minute the key is turned ON because of no oil pressure....makes sense to me.
- The oil, temp, and lube oil alarm go through the ICM and maybe there's an issue with the ICM
- Could just be a pure wiring issue somewhere

I did notice some unconnected wires off the harness in the vicinity of the carb. All the gauges do work.

Either way, I believe there is an issue here and will require some trouble shooting, but I'm not sure if the "delayed" alarm applies to this engine.

Is the ICM just for the TKS or is it on the regular carbed 5.0.

Any off the top thoughts?
 

alldodge

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The ICM can retard timing when the Tan/Blue wire is grounded by (oil pressure, drive lube, etc). To verify if there is a time delay, turn key on and wait, it should come on in less then a minute. If it does not come on, check for 12V on the buzzer, and then ground the Tan/Blue coming off the other side of it
 

badrano

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I found the main cause....someone cut the purple wire to the buzzer. I now may have to cut the zip ties on the wire bundle to find the loose purple wire.
 

alldodge

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Wonder if the buzzer was drawing to much current and blew the fuse. Might also be they didn't want to listen to it anymore
 

badrano

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Found the other end and it looks like it may have been cut once before since there is already a splice crimp connection on it. Luckily there was enough wire coming out of the buzzer to strip the insulation and tie everything back together again.
Knock on wood, I haven't had any issues with unwanted chirping.
 
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