Volvo Penta 290 Trim Sender Wiring Explained

[Jake2603]

I searched high and low and could not get an answer to the following. I have an '88 SunRunner 278 Classic with the old and unreliable V/P little square digital displays with the limits and signal converters built in. I have after trial and error discovered how to wire the sender to work with aftermarket gauges. The wires need to be wired as follows to make the V/P sender work with aftermarket gauges (Faria for Mercury/Volvo specifically) - White w/ Black stripe goes to a good clean ground, White w/ green stripe to sender terminal on gauge, White w/ red stripe optional for a stop (break ground) at about 1/4 lift on the drive (I opted not to use it for now but I plan to in the future using a small relay). You will need to adjust the sender a little bit but it works great. I hope this helps many in the future. I am an industrial controls technician and was confounded as to why it has been said by many this couldn't be done without a V/P control box (Black box).

 

[Scott Danforth]

Way more complicated than simply fixing the gauge

 

[Jake2603]

An additional hint to the above, you will need to take the rack off the the helmet (easy, 1 plastic screw) slowly. When you get to the last tooth engaged right at point the spur gear and rack separate (alignment tooth) mark the spur gear with a sharpie on the tip and a dot on the helmet. Remove the rack and rotate the spur gear 2 teeth to the left (clockwise as viewed from top) and reinstall the rack. You will be in the ballpark on adjustment and you can move the sender around to fine tune (very small window of adjustment). This works fine with old operable senders but you do get a little more accuracy and repeatability with new ones.

 

[Jake2603]

Fixing the old 80's style gauges would have been fine as well but I installed all new modern gauges and dash and thought this would help others do the same if they so choose.

 

[Jake2603]

FYI, from all the research I did, it appears Volvo Penta uses a .9 to 5 volt variable reference for the old style trim gauges with solid state stop limit. This probably does not apply to all gauges but for the small square mid 80's to early 90's it does (it ended with the end of aqauamatic series production). After that, it appears V/P adopted a variation of the OMC syle trim/tilt indication and control.