another query on the AQD40 - battery charging.

[symondo]

we had 1 engine charging fine friday and saturday its not.

Im hoping its not fried the alternator and its somethng like a fuse/loose wire

ive been pawing through manauls for diagrams of wiring, i can only assume they charge batteries through the large cables that are connected to the starter as i cannot see any other way the alternator can get power back to the battery?

the other engine is fine and charges with no issues so i'm hoping to compare the wiring on each but any insight into this would be useful.

 

[Peanuts]

Have to ask, do you by any chance have one of those red handle battery switches mounted in the cable that charges the battery? If so I would suspect that, quickest way to see is to disconnect one lead and connect it directly to the other cable on the same connector, start engine and check the charging voltage at the battery - hopefully that made sense?

 

[Spi D]

Did you check at idle or at higher rpm? Might take a short rev-up to excite the charge

 

[symondo]

Have to ask, do you by any chance have one of those red handle battery switches mounted in the cable that charges the battery? If so I would suspect that, quickest way to see is to disconnect one lead and connect it directly to the other cable on the same connector, start engine and check the charging voltage at the battery - hopefully that made sense?

it doesnt actually

its on the to do list as there is 2 isolator switches which seem to have been removed from circuits - and i suspect this is where from.

We have had the starters replaced so im curious if the cables have been attached securely enough

 

[Peanuts]

"We have had the starters replaced so im curious if the cables have been attached securely enough"

I think that would be a good idea. Have you checked the output from the alternator with the engine running since you noticed the problem?

 

[symondo]

"We have had the starters replaced so im curious if the cables have been attached securely enough"

I think that would be a good idea. Have you checked the output from the alternator with the engine running since you noticed the problem?

When we had it running and revved up she was producing 14v happily on friday
We just pottered about saturday but i noticed the voltage didnt go above 12.4v before eventually dropping to failing to turn the starter without a set of jump leads

Spi D - kinda answers your query too - this was at idle and also low revs but not upper rev range (1200 max)

EDIT _ Not checked the alternator voltage yet - that was the reason of todays visit, so just getting clued up with some info, i also have my printed manual and highlighter with me

 

[symondo]

Did a bit of investigation work...

It appears we may have a dead alternator. I can't get a meter on it when the engine is running, its a bit tight on space. However looking at the gauges its pretty evident that its not doing as it should be.

We tried it on idle and upper revs and I also checked the cabling for continuity at various points

I'm assuming these things are expensive....

 

[rosssavage]

Swap to the other engine to check it's dead before you get a new one.

If it's dead, motor factors can usually rebuild / repair.

If you go for a new one, DONT go to volvo. They're common parts not manufactured by volvo, they're off the shelf motor factor units.

When you get it off, look for a manufacturer and part number. My Volvo engines use Paris Rhone units, and recon and new ones are easily available from non marine sources.

 

[symondo]

Swap to the other engine to check it's dead before you get a new one.

If it's dead, motor factors can usually rebuild / repair.

If you go for a new one, DONT go to volvo. They're common parts not manufactured by volvo, they're off the shelf motor factor units.

When you get it off, look for a manufacturer and part number. My Volvo engines use Paris Rhone units, and recon and new ones are easily available from non marine sources.

Shall do. Will probly use the other engine to suss out how to remove it as visibility and access to the problem part is a bit of a nightmare