Blown Relay

[rossl]

Hi All,

Boat would not start at the weekend and i tracked it down to this relay for the fuel pump. (1996 SAN GT40 MPI Engine on LPG)

RELAY 12V 4RD-Discount Inboard Marine

To get it running I put in an other 30A SPDT relay from maplin.

40A SPNO & 30A SPDT Automotive Relay

It started and ran fine but the rpm would change from 700rpm in neutral at idle as normal to 1350rpm then return to 1000rpm, then up to 1350 again, then return to 700rpm (this happened over a 3 hour period, 10-20mins at each rpm), a bit of a pain when shifting into gear to pull a boarder, apart from that the boat ran fine?? Any ideas if the relay can change the rpm or is it something else.

Cheers
Ross

[ben8473]

Rossl, I would give skidim a call and ask them what they think mate. There aint nothing they dont know about boats. Put a post on one of the nautique specific sites also ( if you haven't already ).

Where's Saltwater Cowboy when you need him....

[saltwater_cowboy]

The RD part in the relay part numbers refferes to resistor - diode.

Basically these have a bit extra gubbins to supress any noise from the switching action.

I think the standard relay you have fitted it spiking the loom and making it go screwy.

[saltwater_cowboy]

Oh just to add if its doing this on LPG as well as petrol then its defo the relay as the excess noise will be keeping the air idle valve open and altering the idle speed.

Oh and you should be able to tell the 2 parts are not the same when you can buy a part cheaper in the UK than the US!

[rossl]

Thanks saltwater, i'll order a couple from skidim (can't seem to find the exact one in the UK). unless somebody know where i can get one?

Cheers
rossl

[saltwater_cowboy]

You should be careful about using it with the current one installed. In theory the voltage spikes could damage the ECU or may have already done so.

I'd get back on to your dealer and let them source the replacement under warranty.