Volvo lift unit wiring

Fishstick

Seaman
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1979 Pierce-Arrow. Volvo 200D with a 280 drive.

I just picked up this boat last month and the previous owner bent the shaft on the lift unit. I picked up another unit and motor (tested out of the boat in both directions) and installed in the boat today. The unit works well going up.......nothing coming down.

P.S. This is the two wire unit.

I'll assume that the previous owner replaced the dash switc as there it no indicator light on the panel. The switch appears to be a dual load momentary switch (two positions on top of the switch and two positions on the bottom of the switch and hot in the center.

There are three wires from the lift unit relay going to the dash switch. Brown, Blue and Yellow/Blue. The dash switch has a purple wire coming in from the ignition to the hot terminal on the switch, the brown wire is plugged in at the top switch terminal, blue wire at the bottom switch terminal and the yellow/blue wire isn't attached to anything. To further confuse me, about a foot up from the relay back at the engine, he cut back the insulation on the wire bundle and cut the yellow/blue wire and crimped on a short piece of wire with a plug that isn't attached to anything either, it's just hanging there by the battery. So the yellow/blue going into the relay is cut. Not really sure what his goal was on this.

I can splice the yellow/blue where he cut it but i'm not really sure how to wire the dash switch. (Mechanical i'm ok, electrical I'm dangerous). I don't really need the indicator light as it's fairly easy to tell when the drive is down and locked in.

Any help from the sages would be appreciated.

Respectfully.
 

Fishstick

Seaman
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Messages
56
Re: Volvo lift unit wiring

Thanks Don

It appears to be wired correctly based on the diagram. Green/Yellow goes to the indicator light which I should probably install one. I'm thinking bad switch at this point. Much appreciated.
 

Fishstick

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Re: Volvo lift unit wiring

Update: "learning as I go"

The dash switch appears to be working on both positions. Initially I had power only in the up position nothing in the down. I swapped the wires at the switch and now have power in the down but not the up position. Motor turned clockwise on both occassions.

Is it the relays in the system that switch polarity to the motor? I'm guessing that one of the two or both is bad and the likely culprit. Am I on track? or should I steer a different course?

Respectfully
 

Don S

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Re: Volvo lift unit wiring

Is it the relays in the system that switch polarity to the motor?

Yes. it takes both relays to change directions. I have tried to troubleshoot those systems systamatically and it's almost impossible to do by yoursel. It's so much easier and faster to replace both relays than to try to figure out which one. Strangest system I have ever seen.
 

Fishstick

Seaman
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Messages
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Re: Volvo lift unit wiring

I will trust your wisdom and just replace them both. Thanks. Fair winds and following seas to ya.
 

Fishstick

Seaman
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Re: Another update/Volvo lift unit wiring

Re: Another update/Volvo lift unit wiring

Stopped by the local boat shop and he had one (and only one) relay in stock. The old part has been replaced by a new aftermarket relay. Just because I had nothing better to do, I wired it up to see if I could get lucky and find the bad one of the two. On the first relay change over, it blew the 15A fuse. Tried the second one and it blew the fuse again. Double checked the wiring and the leads are marked as well as the relay (both old and new are marked the same - so it's somewhat dummy proof thank god) Looking at the replacement, I see it is marked as a 30A while the original was a 20A. I'm guessing that they both need to match up so I'll order the second tmrw. I just need to cross check the schematics to see if the 15A fuse in-line from the main power lead is the appropriate one. Comments?

Update again: Looking at the exploded parts view, I note that the early type calls for a 20A fuse on the main hot wire and a 30A fuse on the late model. So I'm guessing the 15A fuse from the previous owner was inappropriate in either case. As the replacement relay is marked 30A, I'm assuming that the fuse should be the same......and with a 30A relay it seems logical to stop messing around and ensure that both relays are the new ones........correct?
 

Don S

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Re: Another update/Volvo lift unit wiring

Re: Another update/Volvo lift unit wiring

Trust me, the aftermarket relays (from at least from 2 compainies I know of) won't fit inside the box.
If you have 2 bad relays, when you try to operate it with one, it will create a dead short.
PS: 20 or 30A rating is not the problem. That is just the contact rating in the relay. The 30A would work fine, if it fit
 

Fishstick

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Re: Volvo lift unit wiring

Noted. I did note that the new relay has the additional piece on the housing and figured it was going to take some modification for fitting. The marine shop advised to just "carefully" cut off the tab. I'll pick-up a second one, do them both this weekend. So should I stick with the 20A in-line fuse from the main hot lead, or go 30?
 

Don S

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Re: Volvo lift unit wiring

That 20A fuse is only there to protect the control circuit that operates the relays. Should never really see over 1 amp. The motor itself doesn't run off that fuse, it takes a 90A fuse I believe.
 

Fishstick

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Re: Volvo lift unit wiring

Roger that. Thanks again Don. I'll post next week with the results.
 
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