Overheating and Electrical Together??

RJRENTON · Sep 13, 2019

Bobby Sixkiller said:
Try unhooking the alternator and driving it. Just pull the main wire off and tape it up good. The alternator might be causing problems.

If you're considering disconnecting the alternator disconnect one or both field supply wires...the alternator will stop charging. DO NOT JUST DISCONNECT THE ALTERNATORS OUTPUT WIRE while leaving the field wires connected. THIS WILL DAMAGE THE ALTERNATOR'S DIODES. The alternator must be connected to a load when its operating. Just my opinion of course.
Bob Renton

6-david-5 · Sep 13, 2019

I'm quite certain you did not put on too much thread sealer! And it's probably not your spark plugs either. You now have an electrical problem. You have to focus on this. You have to troubleshoot for the symptoms you now have. Bobby Sixkiller mentioned something easy--disconnect the alternator (& wrap the charging wire). Does that change matters? Disconnect the temp sender. Anything? Did you happen to strike the back of the alternator by accident with the pass-side header?? Once long ago, I cracked the ceramic insulator for the output lug--gave me a short to ground!
The Charger looks great, & we want to see you get past this!

493 Mike · Sep 13, 2019

1mightymopar said:
The heads weren't changed. Just added hedders with new hedder bolts. They first leaked, so I pulled them out and added thread sealer. Leaks stopped with that.

My mistake. I read you installed new head bolts.
Mike

1mightymopar · Sep 14, 2019

Thank for all you input guys. I really appreciate it.
I'm in the process of hooking up mechanical gauges, but I think the temp gauge is accurate. It heats up at high speed only. At idle, it's firm at 180.
Can it be the water pump, thermostat or possibly a head gasket? No smoke coming out the back though.

Bobby Sixkiller · Sep 14, 2019

Maybe a sticky thermostat or radiator. You could swap in a 160 thermostat or try running without one to see.

Mikeys73 · Sep 18, 2019

On my 73 B-100 Van I have successfully solved a "fluctuating amp meter" problem by replacing the voltage regulator although the last time I got a "fluctuating amp meter" I swapped out the regulator and it did not fix the problem. I eventually replaced the main charge wire(s) (drilled holes in connector area) an connected directly to amp meter, I also replaced both field wires and installed replacement connector at the voltage regulator.

I resisted this change for years but am happy with the results. My van was far from being "stock" anyway. My advise would be to check all your grounds, the regulator case & the alternator case MUST be grounded with no more than 0.5 ohms of resistance to the negative terminal of the battery.

RJRENTON · Sep 18, 2019

Mikeys73 said:
On my 73 B-100 Van I have successfully solved a "fluctuating amp meter" problem by replacing the voltage regulator although the last time I got a "fluctuating amp meter" I swapped out the regulator and it did not fix the problem. I eventually replaced the main charge wire(s) (drilled holes in connector area) an connected directly to amp meter, I also replaced both field wires and installed replacement connector at the voltage regulator.View attachment 836365 View attachment 836364
I resisted this change for years but am happy with the results. My van was far from being "stock" anyway. My advise would be to check all your grounds, the regulator case & the alternator case MUST be grounded with no more than 0.5 ohms of resistance to the negative terminal of the battery.

Mike....
OUTSTANDING FIX....excellent!!!
BOB RENTON

joemish · Sep 18, 2019

1mightymopar said:
Hey guys, hoping someone can shed some light on what's going on.....

I recently installed a set of headers and did a power steering conversion at the same time. Added new head bolts with some threat sealer to stop leaks.

Ever since the install, my ammeter is boucing around when I'm driving and the temp gauge quickly hits 230-240 when in gear. If i put it in neutral, it comes back down to 170'sh. Never had a heating issue before. Gauge on the rad shows 180. Wondering if the fluid is not properly makes its way around the heads or if this is all connected somehow electrically?? Why does it keep temp in park/neutral, but jump as soon as it's in gear?

Any help is greatly appreciated!!

btw... 906 heads, 440, auto, aluminum rad, tti hedders.

Chances are since fluid leaked when changing headers you have an air pocket inside the block which will over heat very fast like you described. To fix, raise the front end slightly take off radiator cap fill with fluid and run the engine for a few minutes, then let it sit front end raised cap off and engine off. the air bubble will work itself out as it seeks the highest point.

AJ/FormS · Sep 18, 2019

In my understanding, this is purely electrical, and I'm guessing you have a short off the temp-sender wire, that only/mostly manifests when the shifter goes into reverse. It should be an easy fix; just trace and isolate the violet wire.
If a column shift, you may have to climb under there all the way to the cluster.
IMO the ammeter could just be responding to the short.
It could also have something to do with the torque of the engine as it cranks the motor mounts in a backwards direction. Yeah I'm sorta guessing.
It could be in the bulkhead connector, but I'm not sold on that idea.

Good luck; I hate climbing under the dash,lol.

1mightymopar · Sep 21, 2019

I ended up changing the water pump, thermostat and water pump housing and sending unit. Was not good to have to flush and redo this again after 3 times. LoL. Added another ground to the firewall and added mechanical gauges.

Ground fixed the ammeter and the overheating looks like it was a bad thermostat. Pump I pulled off seemed fine. Spins freely.

Thanks all for your help and guidance.

Overheating and Electrical Together??

RJRENTON

FBBO Gold Member

6-david-5

Well-Known Member

493 Mike

FBBO Gold Member

1mightymopar

Well-Known Member

Bobby Sixkiller

Well-Known Member

Mikeys73

Member

RJRENTON

FBBO Gold Member

joemish

Well-Known Member

AJ/FormS

Well-Known Member

1mightymopar

Well-Known Member

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