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Alright. Before my old motor dropped a valve seat the car would get hot. I noticed the fan did work some times but then it just quit all together and now after getting it back up and running I want to fix that issue before the car over heats and potently causes a valve seat to fail.
Here is my thread over on FEOA.net, I wanted to post here to kinda get different answers to things. The current post in my thread on there is what’s been happening recently.
http://www.feoa.net/modules.php?name=Fo … 406#695406
I did the relay mod that’s on there to use standard relays, I’ve checked and triple checked the wiring on those relays. I get power to the relays like stated in that thread but it’s not sending power out from the relays to the fan. The fan indeed works because I wired it right to the battery. Both high and low work.
Thanks
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Quoted From rebel4055:
I didn’t start posting about the fan till page 17, if that helps. The relay mod was just replacing the OE relays with regular 30/40 amp SPDT relays. I checked the wiring on the relays and it matches the diagram they had posted. I used my DMM with the positive probe on the positive battery terminal and the negative probe in the negative of the fan harness.
I have not tried bypassing the relays.
How do I go about doing a voltage drop test?
Didn’t check power at the start cut out relay.
I think maybe you misunderstand how a volt meter works. Think of it as a calculator. The meter subtracts what it sees from one lead and the other, and displays the difference. For example, if your positive lead see 12v, and your negative lead sees 0v, the display will show 12v. That means that you are ‘dropping’ 12v between your connection. I’m not sure if this helps or hurts.
Yeah you lost me. I didn’t know there was some technique to using a DMM.
Or I just didn’t understand how you worded it.
I wasn’t doing the test like shown in the video. All I did was check and see if I had a proper voltage going through the ground. I didn’t preform a voltage drop test like he posted.
And I understand what they are doing in that video. I just have to do it.
Quoted From rebel4055:
Yeah you lost me. I didn’t know there was some technique to using a DMM.
Or I just didn’t understand how you worded it.
Yeh, I figured I might. A dvom doesn’t work like a test light. It’s a more advanced diagnostic tool. I would follow dreamer’s advice and watch the starter video. It shows how to do a voltage drop test on a positive battery cable, but the same theory would apply to testing for voltage drop on the power wires on your cooling fan(s).
Also, you mentioned that you swapped in a ’95 engine into a ’96. I’m not sure how much difference that would make. Did you swap over the sensors etc from the old engine to the ‘new’ one? 1996 was the first year of mandatory consistency on engine controls. But you said the fan problem existed before the swap, so that probably doesn’t make any difference as to your current issue.
I have a test light and a DVOM. Sorry for the confusion there. I did watch the video about the starter and the voltage drop.
Only sensors that needed switching is the IAC and TPS. Figured that out not long after the swap. I had a thread on here about that.
I don’t mean to come off as to I don’t know what I’m doing. I’m not used to doing these testing procedures.
Do you have a wiring diagram for the cooling fans?
If you do, post it here so we can assist you further.
Also what size engine?
Being able to diagnose and fix electrical issues is what separates then men from the boys.
Any body can turn a wrench and change parts but it takes the smarter people to fix and troubleshoot electrical problems. Not everyone can do it and it does take training also.
With you swapping motors, it puts me in a bind as to how to give you advice as im not sure how different the wiring will be between the 2 different year engines.
I would pull both wiring diagrams for both engines and compare.
And i agree with Beefy on the OBD1 and OBD2.
Worst case scenario, you could put the cooling fans in a toggle switch but i myself would troubleshoot and fix the actual issue.
Quoted From rebel4055:
I have a test light and a DVOM. Sorry for the confusion there. I did watch the video about the starter and the voltage drop.
Only sensors that needed switching is the IAC and TPS. Figured that out not long after the swap. I had a thread on here about that.
I don’t mean to come off as to I don’t know what I’m doing. I’m not used to doing these testing procedures.
I wasn’t trying to call you out bro. I’m just suggesting that using a dvom properly is not as easy as you would think. I ran into the same problems before I went to college and was properly schooled as to what a dvom does and how to use it. No offense was intended.
According to that diagram you posted (i found one that is totally different but i need to know your engine size), the high speed fan relay is ground switch.
Did you check that wiring coming from the PCM? The low speed relay is also ground switched.
The PCM will command those fans on from data from the ECT or from the temperature switch (again engine dependent).
I used this link –
Oh I understand. I know where your coming from and I took your response as to I should learn a few more things. No problem over here bro!
Nothing is different besides the TPS and IAC. The wiring is virtually the same between cars. Only thing wiring that was swapped was the engine harness. It’s completely separate from the vehicles. Wiring for the ECT and stuff is vehicle related and is the same between second gens OBD or OBD-II.
There is a wiring issue somewhere for the relay not allowing power to be sent to the fans. But all the wiring that goes to the relay seems to be working. It’s just not allowing power.
According the those wiring diagrams at BBB Industries, the cooling fans will not come on till the engine reaches 220 and 230 deg.
Do you have a scan tool to look at live PID data?
It wont send power to the fans till the PCM commands the relays on.
If the cooling fans have a bad ground, then it will affect current flow.
Think of voltage as electrical pressure. More pressure = less current flow. Less pressure = more current flow. So in essence, if the cooling fan motors were working and you checked the voltage at the motor, it would read around 0v. This is because there is no electrical pressure as the circuit is energized, the cooling fan motors are running and there is high current flow. (Using those numbers as an example in aid to help you on how electricity flows.)
Again, once your comfortable, i would jumper the relays with a 40amp fused jumper wire and see if the cooling fans kick on.
But you have alot more to check before even doing that.
I hope the above makes sense as im dead tired.
The motor is the 1.9. I don’t have any scanners or diagnostic equipment. Just a test light and a DMM and some paitience lol.
Yes I know the fan won’t kick on till a certain temperature. I did the key on fuse out trick to make the car think something is wrong and needs to turn the fan on. Also let the car warm up and unplugged the ECT to make it think it’s over heating. I hear the relay(s) click but the fan doesn’t come on.
If you go to the last page on that thread I linked you can see what I’ve done.
The wiring diagram you posted, is that the correct one for your vehicle?
When you put 12v to the cooling fan motors, did you just jumper the yellow or LG/Yellow wire? Or did you use 2 jumper leads and jump the yellow and black?
If both relays are clicking, that means the PCM see’s the signal to operate the fans. So focus your efforts on the Yellow and LG/Yellow wires when the vehicle is running. You need to see if you have power coming from the relays once activated.
I would also do a voltage drop test on the ground side of the cooling fans.
This is all going by that diagram you posted.
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