Tested two different computers, checked relays and do continuity for all wires connected to the relay and it won't kick on or provide power. I tested it on my 87 Lancer and the fan comes on as soon as you disconnect the plug to the CTS. Car is an 88 CSX T with the SMEC. Thoughts on what to check next?
[SIZE="3"] [B]Jon Trotter[/B][/SIZE] [B]1985[/B] Dodge Shelby Charger, Currently decommissioned [B]1987[/B] Shelby GLHS, #937 [B]1987[/B] Shelby Lancer, #628 [QUOTE=Reeves;587010]I can be ready. Please send pics of wife. _____DodgeZ add comments here______[/QUOTE]
Sounds weird.
Does the fan come on when the engine temp gets high?
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
From what he told us, it will not come on. We didn't want to try and get the car hot to test, so we spent time trying to diagnose why the fan wouldn't come on in the basic sense disconnecting the CTS.
[SIZE="3"] [B]Jon Trotter[/B][/SIZE] [B]1985[/B] Dodge Shelby Charger, Currently decommissioned [B]1987[/B] Shelby GLHS, #937 [B]1987[/B] Shelby Lancer, #628 [QUOTE=Reeves;587010]I can be ready. Please send pics of wife. _____DodgeZ add comments here______[/QUOTE]
When you unplugged the CTS, did the car change at all? When you unplug the CTS and the ecu sees the failed sensor it defaults and it does change the timing and other things. Should have made some kind of operational difference like a brief stumble or something. When the fan comes on, it kicks the AIS, so since it didn't, you might not have seen a change in idle rpm but it still should have defaulted to the failed CTS value. Did the fan relay even click when you unplugged CTS?
Do you have a drb? You can test the fan from actuator tests.
I forget which terminal it is, but grounding a terminal on the relay starts the fan.
You did check the fan to see that it does work if you power with 12v with some test leads directly to battery?
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Applying ground directly to the relay it activates and we get 12 volts @ the fan connector. When we unplug the cts the relay never activates. We verified all the wires going in and out of the relay are good with an ohm meter end to end. Verified all grounds going to the smec are good. I'm going back friday with a known good smec.
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Are you getting power to the relay? Fusible link might be blown. If you get power and ground to the fan (by unplugging the CTS) and the fan still won't come on, test the fan by itself. If the fan doesn't work with power and ground jumper wires hooked up the fan is bad. If the fan works you could have a bad fan relay. The relay could provide power, enough to show power on a meter, but once you put a load on the system the contacts in the relay "break" because the contacts are bad when amperage spikes.Originally Posted by minigts
the relays are good because i have changed them twice ( i am owner of the car in question). it does not have a rad or coolant in it at the moment so we couldnt run the car long enough for the fans to come on or else the engine would have gone into chernobyl meltdown mode (always not a good plan) we tested the relay by itself and it is good. i have tested the fan with a powerprobe and it is good. (great tool to have by the way. worth every penny.)
How? I've been burned in the past by only testing a relay for voltage and not load testing the circuit. Are you getting power to the fan through the relay when you unplug the CTS?
It gets zero volts unless you manually ground the relay. We can worry about the fan being good or bad once we even get it to turn the relay on. I think the smec is bad, which I will verify friday.
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the fan is not coming on when you pull the plug for the CTS.
No
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To clarify....You have good power and ground on the signal circuit of the relay, correct?
If you put power to the Batt side of the fan motor, it works, correct?
Have you guys verified the grounds are all good for these circuits?
Bryan
86 GLHS #161, 2016 Impala
SDAC National Member, SDAC Buckeye Chapter Member
A man has got to know his limitations.....
If we manually ground the relay it works. All the grounds going in to the smec are good. No ground on output of smec to the relay. Verified the ground wire from the smec to the relay is good with an ohm meter.
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Is the fan supposed to come on when you unplug the CTS and the car isn't running? If you flip the key forward and the fuel pump primes, the SMEC is almost certainly good.
we tried it on two different cars by pulling the plug on the CTS and the cars wernt running at the time and they both kicked on in both cars
You have tested the continuity between the ground on. The relay and the SMEC right? Have you visually inspected the wires? Perhaps it can't handle even the slightest load even though it tests good continuity wise?
Been screwed by that exact statement before and I made it. I have honestly seen 1-2 strands give a continuity reading but won't power the circuit. Saw it on an IAC circuit on a buick. Ran a jumper wire from the connector to the ECM and the idle raised when the a/c was turned on. It may not be it, but running a wire from it to the SMEC would eliminate it.
Bryan
86 GLHS #161, 2016 Impala
SDAC National Member, SDAC Buckeye Chapter Member
A man has got to know his limitations.....
I'm convinced that this is what was causing my old GLHT to cut out at 6PSI.
Did some more testing today. If you manually apply a ground to pin #57 of the smec, the relay activates and the fan runs. This means that the wiring to and from the relay and the fan motor are good. For some reason the smec is not applying ground to pin #57 like it should. We used a known good smec verified on my GLHS still only works as discribed above.
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There must be a problem with wiring somewhere on the car. Maybe grounds to to SMEC are bad? There's no way two SMECs in a row are bad.
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