heat

[koontreeguy]

5.0- bronco runs great but when ever I turn the heat ON the gauge says it starts getting hot, and will even go above operating range heading up a hill occasionally. it never overheated after it went above the operating temp like spewed water or anything so I'm thinking the gauge is feeding me some bs. any thoughts ?

 

[miesk5]

yo K!

Testing;

Pull the wire off the sender & ground it to the block or ground ***** nearby

turn the key to run

if the needle pegs, replace the sender

If not, diagnose the circuit.

Sender Location pic in 84-86 5.0 (ECT & Temperature Gauge Sending Unit)

by Ryan M (Fireguy50) at fordfuelinjection.com

Installation pic in an 86 5.0; pic #1

Source: by Sixlitre (Malcolm H, Eddie Bauer) at SuperMotors.net

Wiring Diagram in an 86

Source: by Xris at SuperMotors.net

 

[koontreeguy]

holy crap! if it's not the sender idea then I'm just gonna have to say f it. hahaha--- nevermind, I just took a closer look at the diagram and it don't seem so bad. once I get home Saturday I'll check out the bronc. thanks M!!

 

[miesk5]

yo,

yw

BTW, I ASSume (yeah, ima a** lol)

the other gauges are ok?

Because;

Instrument Voltage Regulator (IVR) in 78-86;

"...The IVR can fail two different ways. it will quit working altogether, thus none of the gauges will work. Or two, it will stick, and the gauges will peg to the extreme right, then it will unstick and fall back to normal. The IVR is a pulse type. The voltage is regulated by how fast the pulses are. When it sticks, it doesn't pulse, etc... Try tapping on it. Make sure the cluster ground is in good shape. If the IVR isn't grounded or has an intermittant ground, it wont pulse like it should either. Rebuild it, see http://www.turbocoupe.org/techinfo/ivr/IVR.htmold or,Suggest getting one from a Yard; Since there are about 12 different types, make sure to take the old one with you; Fits: 1971/86 F100/350; 1971/91 Econoline; 1978/86 Bronco; 1977/79 LTD II/Ranchero/Cougar/Thunderbird without Tachometer; 1972/76 Thunderbird/Continental Mark IV; 1971/72 LTD/Mercury Marquis for MOTORCRAFT Part # GR513 {D1AF10804AA, D1AZ10804A}..."

Source: by miesk5

 

[koontreeguy]

well come to think of it the oil pressure gauge drops to below operating range when I stop at a stop sign/stop light. but only after the truck is warm. it dosent knock or run any differently at all when that happens and I didn't even think to mention it (if it's even related). but the rest of the gauges work fine if memory serves me right

 

[Seabronc]

well come to think of it the oil pressure gauge drops to below operating range when I stop at a stop sign/stop light. but only after the truck is warm. it dosent knock or run any differently at all when that happens and I didn't even think to mention it (if it's even related). but the rest of the gauges work fine if memory serves me right

The oil pressure gauge problem may or may not be related. The sender unit is a common problem for the oil pressure gauge. Also, that could be an indication the main bearings are getting worn. Mine does the same thing and I finally just installed a wet oil pressure gauge so I could see what it actually was. The pressure does drop at stop lights when the engine is up to operating temperature for a while, but never to "0". The fact that you don't hear any unusual noise when you see this indicates you are at least getting some pressure. As a rule of thumb, about 10 lbs per 1000 RPM is good and my wet gauge shows that to be what I get, maybe just a little higher than that. I have worn main bearings, but have been keeping it going just fine for 4 years now while I get around to replacing the engine by using 20W-50 and Lucas Heavy Duty Oil Stabilizer. The reason for the procrastination on replacing the engine is that it runs strong and smooth the way it is.

Like miesk5 said, the IVR operates the Oil, Fuel, and Heat gages. The problem could be that or just a bad sender in the water jacket of the intake manifold. Senders are not expensive and real easy to replace. If you replace that senders, do not use Teflon tape on the threads. You need that contact to get a good ground for the sender, the threads are designed to make the seal.

Good luck,

>-

 

[koontreeguy]

thanks you guys. I grounded the wire like u said M, and the temp flew all the way up with the key on. and thanks for the heads up with the Teflon tape seabronc!!