I put a mechanical gauge in the left head of the truck and ran a ground wire from the one on the right to the engine block. As I know the left temp unit one needed to be grounded to make the gauge (electrical gauge) to work. Drove the truck about ten miles and the mechanical gauge read about 179 to 180 which I think is pretty good (if that is right for a flathead to be running) while the electrical gauge didn't move till I was about five miles down the road. Then It started to move at a steady pace till it peged out hot. I was driving about 50 to 55 mile an hour. The right temp unit is the one that has two electrical heads on it so I thought in order for it to work I had to ground the wire to the left one. When I didn't ground it the electrical gauge would not move when key was turned on but when I did ground it it worked like it should with going all the way to cold first.

I have been looking for a fan shroud to go on the truck with no luck yet but I PM Denny and he said he might be able to help me out on that. Went to a car and truck show today and talked to an elderly man there for about an hour. He has a 56 ford and he said all the same things about the shroud on the truck and it making a world of difference in the temp of the engine. The elderly gentleman also told me to put have water and have acid in the engine and run it for a short time to clean out any deposits of rust or to help open any water jackets that might be half plugged up. Is this the right thing to do and if so what kind of acid should I go buy? So I'm still looking. Anyone have any ideas besides me going to a machine shop and having a shroud made which will propably cost me a small fortune.

Julie I had to order the flame thrower 12 volt coil for the truck as noone around here including Napa has ever heard of one. I ordered one on line and hope it will be delivered this next week. We have poor part houses around this area. I know from reading a lot of threads that Napa is where you all get a lot of parts from. I also asked while I was there if they (Napa) could get any water pumps for the 239 and yes they could but only the right one as the computer said the left one was not avalible. I was just asking while I was there not that I'm going to buy them untill I try what you all told me to try first.
Thanks for any replys,

Larry
713-410-7481
braular@yahoo.com

 

If you still have the 180 'stat installed, then your cooling system is working better than you could ever ask. The 'stat is regulating the temperature exactly to it's rating and your radiator isn't letting it go up one degree farther. Do you need any more evidence that your engine and cooling system is perfectly fine?

 

Yeah I agree with Wayne on the temps with the mechanical gauge. After reading your post I think there is some confusion on the wiring,or the senders on the electric gauge. We'll look at that tomorrow.

In the mean time, you can always check be flip flopping the electric sender and the mechanical gauge from side to side and re test/compare the temps.

Oddly, I just posted on another thread where the member got a new sender adn his gauge was pegging too.

 

Thanks for the replys and I'll do some flip flopping on the electrical gauge.

 

No, what I meant was to move the mechanical gauge to the other side, so you can read that sides temps while driving now, and hook up the electric gauge sender on the side opposite the new position of the mechanical - that kind of flip flop.

Please confirm for me that you have installed the voltage reducer on the back of your stock electric gauge for use with the 12 volt electrical system.

 

Yes I did install the reducer on that one gauge.Oh I will put the mechanical gauge ing the other head and drive it to see if it reads about the same thing.
thanks Julie

 

Larry , check your e-mail . All the fan shroud details are addressed .Do you have the under engine air defector pan on your truck ? Later , Denny

 

No I don't have the under engine air defector pan on the truck that I know of. I'm assuming that this is a air deflector that doesn't let the air go straight by the engine underneth. It's wide open under there or am I not understanding what I am looking for?

 

52 Merc I have 160 therostats in the 239 and not the 180's I think if I'm not mistaken that is what Ross is running in his is 160 but I have read so many different threads on this that I could be mistaken.

 

Lbraur
The thermostats only control the minimum temp of your engine. If you have 160 stats they will close and make your engine heat to 160 then they open wide open. If you engine cools down below 160 they will close forcing the engine heat back to 160. After the 160 is reached it's up to the radiator, water pumps, coolant flow, and air flow to keep it from over heating. If your flathead is driving with the temp at 180 your doing as well as you are likely to do. Enjoy you truck, you not overheating.
The mechanical gauge is a much better indicator of your engine heat than the electric dash unit will ever be but to be in a perfect world you would need two mechanical gauges, one on each head..

 

Hmmmph, this is a little weird. I'll have to think about it for awhile - there's just not a whole lot left that we haven't checked wrt the electric gauge working right.

 

Sorry Larry, I didn't catch that you were using the two-terminal unit alone; that isn't correct. That is the Excessive Heat unit, and no, it should not be grounded on one side. See below, you want to install the single terminal unit, period. Under normal conditions, current flows thru the Excessive Heat unit to the single terminal unit, which varies the current with temperature. Try it that way.

It does seem like your engine is working OK, that is good news!

 

Julie,

I just sent you a message but I did it in the thread about 9mpg. Did you /can you get that?

Michael

 

Julie maybe I didn't explain myself like I thought I did in that post. What I did was remove the single post unit and inserted the mechanical gauge there. But when I turned the key on the temp gauge didn't move to cold like it should have so I thought it was because it needed to be grounded on the single post side. After I did ground from the wire that comes from the excessive heat unit wire that goes to the single unit the gauge went to cold like it is supost to do. I looked at the service bulleton and they say at the bottom of the units that the excessive unit goes in the left head and the single post in the right head. All the places that I got the units from tech told me that it was just the oppisite. Do you think it really matters which side they are in? I have the larger post on the two unit going to the single unit like the pic shows and the smaller of the two post going to the gauge than to the ignition switch. I can change the two to different heads if it will make a difference. Maybe I was told wrong from the teck support people I don't know. I know the gauge will not work with only one unit hooked up. Let me know if I should change the units to the different heads. One way or another we will get to the bottom of this gauge bussiness.
Thanks
Larry brauer
713-410-7481

 

That's what he was told to do in the first place Ross. The diagram was posted in the other thread about 3 days ago with the instructions you just passed again.

The problem with this is that he has three threads going on and they are all out of sync. So he's chasing his tail by undoing on one thread what he's been told to do on the other.

OK,

Please erase everything you are thinking about the electric gauge and sending units in your mind and lets start over.

There are two sending units and one gauge. They are made for a 6 volt electrical system. You installed the voltage reducer - to use it on 12 volt.

One sending unit provides the ground for the temperature gauge circuit. This is the one post unit.

The other sender, the two post sender, is a simple electrical bridge that allows power to flow over to the one post sender.

When the engine is cold, the one post sender allows all the electricity to flow to ground. As the engine warms up, the one post sender starts to restrict the flow of electricity to ground - more so with more heat - and that is what causes the gauge needle to move up.

The two post sending unit is a simple on/off switch and it is normally "on". It allows the electricity to flow from the gauge all the way over to the one post sensor. It's an electrical bridge.

If the engine gets too hot, the two post sensor turns off it's switch, there's no longer an electrical bridge, and the electricity that is supposed to flow to the one post sender (which is providing the ground for the circuit) is cut off (so there's no ground). That causes the gauge to move to hot position - same as if you shut off the ignition.

Your power on your set up should flow from where ever you gauges get power, to the voltage reducer and into the gauge. Then it should leave the other stud on the gauge, go in and out of the two post sender, then over to the one post sender.

It doesn't matter what side either is on as long as power flows from the gauge, through the two post sender first, then over to the single post sender.

It's just that simple. Forget everything else.

FOR NOW, take out the two post sender. Take it completely off the truck along with the wire that connects it to the one post sender. Take that two post sender and that wire completely off the truck and set them on the work bench.

Connect the wire that used to hook up to the two post sender (coming from the gauge) to the one post sender. PERIOD!

The gauge will work as it is supposed to. That is the exact set up as on a 6 Cylinder. The single sender on the one head.

In the hole that you took the two post sender out of, install the mechanical gauge.

When you flip flop the gauges as I mentioned, remove the one post sender and the mechanical gauge sender. Put the one post sender in the hole the mechanical gauge used to be in, and hook up the wire from the gauge to it, then install the mechanical gauge in the hole the one post electric sender used to be in.

That's all. Drive it and take readings off both gauges while driving, then come back, flip flop the senders and drive it again taking readings.