Hydramaster cds 4.7 question

[Larry B]

On a Hydramaster 4.7 CDS what makes the "Service Warning" Light come on?

Just picked up another one of theses machines and it was running fine when i purchased it. Now 2 days later went to start the machine and when you turn the key there is a solenoid clicking and the "Service Warning" light is on.

Any ideas?

 

[Larry B]

Any ideas?


.... while Peeing into the vacuum hose

 

[dgardner]

According to the info I have, either high engine temp or low engine oil pressure will turn on the alarm lamp and prevent the clutch from engaging. There should be a green/white wire (#9) going to a temperature switch on the engine, likewise a blue wire (#12) to an oil pressure switch on the engine. If either of these wires are grounded, the CDS won't run.

If this is what's happening to you, the problem could be:

• You actually have a high temp or low pressure condition - or
• One of the two sensors is bad - or
• One of the two wires is shorted to ground between the CDS and the sensor(s)

If you temporarily disconnect the two wires at the CDS and it runs fine, that's your problem. Hook them back up one at a time, and which ever one kills it will be the culprit.

If the relays on the CDS are marked, both wires will be on relay CR-6, on the same terminal in fact.

If none of this makes sense, it's because I had a big cup of hot chocolate (lots of caffeine) just before bed and I can't sleep - which is why I'm typing this at 2 in the morning.....

 

[Larry B]

Thanks Dan
The info was correct it had to do with the van engine oil pressure. Oil pump pressure was dropping and needed a new oil pump installed.

 

[JS41035]

Ouch. Hope you got a good deal


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