What is best way to add temp gauge to 1985 v-6 merc?

[OceanVU]

the old wire to the "buzzer" horn temp alarm corroded out. Anybody have any recommendation on installing temp gauge on older v-6 mercs? The original motor alarm is only on 1-3-5 head. Anyone add gauge to both heads?

Thanks

 

[j_martin]

Re: What is best way to add temp gauge to 1985 v-6 merc?

Odds are good the other head has a temp gauge sender already installed and wired. Just add the gauge. Hooks up to the instrument harness from the controls.

You can put a sender on each head, and 2 gauges. It's hard to rig up 2 senders to 1 gauge, and even if you got it to work, it would be an average temp, and it would be possible to overheat one side and never know it. Back in the 50's and 60's, we burned down many flathead ford v8's because one of the 2 water pump belts blew off and the temp gauge didn't get into the warning area till the block was cracked.

I think a water pressure gauge is more helpful in preventing failure. If you have any water pressure at all, and it goes up when you speed up, and your pee stream is warm to the touch, yer good.

hope it helps
John

 

[gss036]

Re: What is best way to add temp gauge to 1985 v-6 merc?

I suspect that the one on the 1-3-5 head is for "OVERHEAT". Usually installed on the starboard head and the port side is the temp guage, completly different looking senders.

 

[Silvertip]

Re: What is best way to add temp gauge to 1985 v-6 merc?

Two senders and one gauge is not difficult to hook up and it does not read an average. You simply add a switch to allow you read either head on the same gauge -- not both at the same time.

 

[Yepblaze]

Re: What is best way to add temp gauge to 1985 v-6 merc?

Two senders and one gauge is not difficult to hook up and it does not read an average. You simply add a switch to allow you read either head on the same gauge -- not both at the same time.

Not to be-little you in any way.

But then they start posting......

Why does the right head run at this temp when I do this, but the left one at something else when I do that?

 

[Silvertip]

Re: What is best way to add temp gauge to 1985 v-6 merc?

They will very likely run at different temperatures because of differences in the two senders and the fact that the two sides can and often do run at different temperatures. My question to you is how different are the numbers.

 

[OceanVU]

Re: What is best way to add temp gauge to 1985 v-6 merc?

Thanks for your suggestions. I checked out some kits that come with a sender and gauge for about $50. I don't think my old motor has an existing temp gauge sender, just the old warning buzzer. (can't find any sender on port head). I already have a water pressure gauge, but I think i will add temp gauge and just leave the buzzer disconnected.