Volvo Penta Tachometer intermitant

[Rich and Nancy]

I have a Volvo 2002 two cylinder diesel in my early model Ranger 21. It has the Delux instrument panel. The tachometer and hour meter cut in and out every trip. I have checked the wiring harness connections and everything seems to be okay. I'm wondering if anyone has seen this problem or have any ideas that I can check out. Thanks. Rich

 

[bbrh842]

Had same problem with my Yanmar. Found out the tachometer gets it's feed from the alternator. Whoodathunk. There was a small wire plugged into the back of the alternator with a jack similar to that on a telephone. I jiggled the plug. Tachometer has been working fine ever since. That was two years ago. Good luck.

 

[Rich and Nancy]

Thanks. I'm going to check that. I have been wondering how rpms are counted on a diesel engine, since there is nothing "electric" about the ignition.

 

[mspaugy]

Many diesel engines have a magnetic pickup on the flywheel housing that counts rpm on the flywheel.

 

[craigf]

Same problem I had with volvo 2030 engine. Deluxe panel. the left tack would still show rpms but the hour digital woult not lite up. I finally got pissed enough to pull the inst. again and push and and wiggle the connection. thank god that did the trick.. Now the boat is sold and I don't worry about it any more.

What really irks me with Volvo and I suppose Yanmar is same. We had twin diesels. Tacks had to be replaced after lightning strike. One tack was still working so kept in place with the replacemnet ready. volvo at that time did not have a way to equalize the tacks times. so you were in constant flux doing the math.. But I hear tell they have fixed that.

pa

looking for a ranger or rossy