Well...It was a day.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

hey mister

Full Access Member
Joined
Jun 15, 2024
Posts
213
Reaction score
563
Location
North Coast
First Name
Marty
Truck Year
1978
Truck Model
C10
Engine Size
350
Finally got the radiator thing sorted out...for now.
It started about a month ago. The newly converted, rad/elec fan upgrade started to overheat. This was caused by the fans just not turning on when they were supposed to. Even the manual over ride would not function.
The coolant had also become very cloudy, like pond scum and it's only 6 months old. Unacceptable, for sure.
So, drained the coolant and flushed every thing until clear and then some. Pulled the thermostat and boiled the new one. It opened at 185°.
Got Zerox, original formula for old cars. Mixed it 50/50 and poured it in. Purged the air and topped off the overflow. Ran it up to temp and the fans kicked on.
Everything seemed to going well. Screwed down rad cap and waited for another fan cycle. It never came. Temp started to climb to second hash mark. Flipped the fan manual over ride switch...nothing. Temp got to second hash mark...no fans. Both should be screaming on, long ago. I decide to tap the controller relays with my finger.. both fans wake up. Temp immediately immediatly starts to drop.
Now, Iv'e been suspecting a bad relay for a while, but it wasn't consistant. One minute, fine..next minute, nada, next minute, fine.
So now I'm on the phone to Summit. Told him the issues and symptoms, had to, his name was Doc. He warrentied out the old controller and said, we don't need it back. Great, that works. Drove over and pcked up the same controller. Got home and swapped out the 2 relays. Fired it up and everything seems to work as it did 6 months ago, when new. Question is: How long will it last? Is it a fluke or a trend?
Only the "Shadow" knows...

BTW the fans are rated 28amps and the relays are 40amps. Each fan has a relay.
Now unless one of Mao's workers has not been forthright on the fan and relay ratings, there shouldn't be a problem.
But it wouldn't be the first time, some specs have been fudged. We'll see...
 

Hunter79764

Full Access Member
Joined
Sep 1, 2021
Posts
343
Reaction score
527
Location
Grand Prairie, TX
First Name
Shawn
Truck Year
1987
Truck Model
Suburban V20
Engine Size
350
I had a buddy that ruined a fresh built 351 with a similar situation, temp controller had a temp readout that was showing low from what I remember, waited for it to get to "180°" and only saw that it was well overheated after damage was already done. Also a good reminder to hold off on those next two beers until after the trigger has been set on something like that...

If it was me, I'd do some exploratory surgery on the old relay connections. See if they are obviously loose or anything clear like that. Then using what you know, open up the new one and take a look-see to see if the same issues are there. If you don't see anything and don't trust it still, I'd be tempted to run an external relay completely independent of the controller you have, and run your manual override through that. The relay(s) wouldn't have to be as overbuilt for that, since you shouldn't be using it very often...
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,714
Reaction score
18,010
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
I've had some relays that had that dark gummy stuff on them, supposedly to keep water out, to actually cause a 'no connection' condition.
I cleaned out the old gummy stuff with brake cleaner and slathered some dielectric grease on them. End of problem.
 

hey mister

Full Access Member
Joined
Jun 15, 2024
Posts
213
Reaction score
563
Location
North Coast
First Name
Marty
Truck Year
1978
Truck Model
C10
Engine Size
350
I had a buddy that ruined a fresh built 351 with a similar situation, temp controller had a temp readout that was showing low from what I remember, waited for it to get to "180°" and only saw that it was well overheated after damage was already done. Also a good reminder to hold off on those next two beers until after the trigger has been set on something like that...

If it was me, I'd do some exploratory surgery on the old relay connections. See if they are obviously loose or anything clear like that. Then using what you know, open up the new one and take a look-see to see if the same issues are there. If you don't see anything and don't trust it still, I'd be tempted to run an external relay completely independent of the controller you have, and run your manual override through that. The relay(s) wouldn't have to be as overbuilt for that, since you shouldn't be using it very often...
So...my beer drinking goes with the pizza or similiar meal.
Rarely do I have more than one. I enjoy the refresh, just not the swimmy head. I'm a light weight...certainly not holding up my Irish German roots very well...lol
 

Forum statistics

Threads
44,100
Posts
949,371
Members
36,197
Latest member
squarebody2013
Top