Gary Lewis Posted November 15, 2021 Share Posted November 15, 2021 I did not remove any ducts. That may have made it even easier but I did get it out without removing them. Good to know. Thanks. Link to comment Share on other sites More sharing options...
Atlas75 Posted November 23, 2021 Author Share Posted November 23, 2021 It'll draw some. But if it has power all the time then the ignition switch isn't the problem. Going back to the tach…my test light is telling me that the 12v supply and the grounds are all good. I have yet to test the tach signal from the coil all the way to the tach but I did trace it under the hood and it was getting as far as the connections by the duraspark box. Hopefully tomorrow I can check it at the tach. If it is bad I bet it got ruined when I jumped the vehicle with the tach connected to battery. So much for my great salvage yard find…maybe! Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 23, 2021 Share Posted November 23, 2021 Going back to the tach…my test light is telling me that the 12v supply and the grounds are all good. I have yet to test the tach signal from the coil all the way to the tach but I did trace it under the hood and it was getting as far as the connections by the duraspark box. Hopefully tomorrow I can check it at the tach. If it is bad I bet it got ruined when I jumped the vehicle with the tach connected to battery. So much for my great salvage yard find…maybe! I hope the tach is fine and the problem is elsewhere. Good luck! Link to comment Share on other sites More sharing options...
Atlas75 Posted November 24, 2021 Author Share Posted November 24, 2021 I hope the tach is fine and the problem is elsewhere. Good luck! Well it’s confirmed. I have tach signal at the tach so I must have smoked the tach. Well…live and learn I guess. I have another question. Neither my factory temp gauge nor the aftermarket temp gauge have worked since I bought the truck. Today I replaced the old aftermarket gauge with a new one and it doesn’t work either. Now I am starting to think something else is going on. Where should the aftermarket gauge be plumbed in? I put the new one right where the old one was, which is on the radiator side of the thermostat about 2 inches past the thermostat. Is that a proper location? If the thermostat was missing or stuck open would the engine get hot enough to register on either gauge? Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 24, 2021 Share Posted November 24, 2021 Well it’s confirmed. I have tach signal at the tach so I must have smoked the tach. Well…live and learn I guess. I have another question. Neither my factory temp gauge nor the aftermarket temp gauge have worked since I bought the truck. Today I replaced the old aftermarket gauge with a new one and it doesn’t work either. Now I am starting to think something else is going on. Where should the aftermarket gauge be plumbed in? I put the new one right where the old one was, which is on the radiator side of the thermostat about 2 inches past the thermostat. Is that a proper location? If the thermostat was missing or stuck open would the engine get hot enough to register on either gauge? Bummer! Sorry about the tach. As for the temp gauge, if the factory gauge worked then having another gauge after the thermostat wouldn't be an issue. But I believe you need at least one gauge monitoring the engine's temp, and after the 'stat wouldn't show engine temp if the 'stat were to stick closed. I have both the factory and the aftermarket gauges ahead of the 'stat on Big Blue. Link to comment Share on other sites More sharing options...
Atlas75 Posted November 24, 2021 Author Share Posted November 24, 2021 Bummer! Sorry about the tach. As for the temp gauge, if the factory gauge worked then having another gauge after the thermostat wouldn't be an issue. But I believe you need at least one gauge monitoring the engine's temp, and after the 'stat wouldn't show engine temp if the 'stat were to stick closed. I have both the factory and the aftermarket gauges ahead of the 'stat on Big Blue. Do the 351M and 400 use the Cleveland style thermostat? Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 24, 2021 Share Posted November 24, 2021 Do the 351M and 400 use the Cleveland style thermostat? Yes! See the page at Documentation/Cooling Systems/Thermostats. And that has a link to the 351M/400 page IIRC that has pics. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted November 25, 2021 Share Posted November 25, 2021 Yes! See the page at Documentation/Cooling Systems/Thermostats. And that has a link to the 351M/400 page IIRC that has pics. You didnt use sealing tape on the sender did you ? they need to ground to the motor and the tape can stop this. If you ground the sender wires and turn the key on do the gauges move? If they dont move you need to work back to the gauges. Do you have power to the after market gauge? Dose the fuel gauge & oil gauge work? Dave ---- Link to comment Share on other sites More sharing options...
Atlas75 Posted November 25, 2021 Author Share Posted November 25, 2021 You didnt use sealing tape on the sender did you ? they need to ground to the motor and the tape can stop this. If you ground the sender wires and turn the key on do the gauges move? If they dont move you need to work back to the gauges. Do you have power to the after market gauge? Dose the fuel gauge & oil gauge work? Dave ---- Oil and fuel gauges work as they should. On the aftermarket gauge I installed, I did not use any pipe tape and the only power needed is to run the back lighting if needed. This particular gauge has the ether filled line from sender to gauge. I have not done anything to the factory sender. I did find a troubleshooting guide in my 1980 EVTM but have yet to perform the test. I will also try grounding the wire on the sender to see if the gauge moves. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted November 26, 2021 Share Posted November 26, 2021 Oil and fuel gauges work as they should. On the aftermarket gauge I installed, I did not use any pipe tape and the only power needed is to run the back lighting if needed. This particular gauge has the ether filled line from sender to gauge. I have not done anything to the factory sender. I did find a troubleshooting guide in my 1980 EVTM but have yet to perform the test. I will also try grounding the wire on the sender to see if the gauge moves. Well if the after market gauge is a mechanical there is no reason why it should not work Unless it is not in water to pick up the heat? Boil a pot of water and dip the sender in it and see if it moves. If not bad gauge. On the factory grounding the wire is the easiest way. If you have a test light you can put it on the wire and to ground and it should blink if all is good back to the cluster. They say you can also swap the oil & temp wires on the senders as the gauges are the same just marked oil & temp but work the same. My factory oil gauge stopped working today just have not done the testing to see if gauge (hope not) or the 2 year old sender. Dave ---- Link to comment Share on other sites More sharing options...
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