Quote:
Originally Posted by Arthur Dalton
The BM is the ground end of the circuit and that is where the switching is done...but in order for it to switch [ and therefor complete the circuit] it has to have the criteria met so, the engine has to be cold ,the rpms have to be idle or slightly above, and the MAF has to be satisfied with air flow spec. That is why I asked if that 5 V went away when the car was warmed up. It may be that when the old relays coil shorted , it did some damage to the switching transistor driver circuit in the BM..I do not know that.
Can you confirm you have 12v to 85/86 when the relay is plugged in ??
maybe some back -probing.. you should only get 12v when the car is COLD..and the engine has to be running...
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Arthur,
I will try to test the "losing 12 volts when the relay goes back in" idea. Naturally...I have to have 12 volts to start the test - and this isn't always the case. So I might not get this condition tonight - I may have to wait until tomorrow. But I'll try.
I think if I jumper run some wires out from the pins, I can take a reading.
As to the criteria, I totally understand the first two - coolant temperature and rpms. But a question or two if I may about the second two:
1. What do you mean the MAF has to be satisfied with air flow? I presume "sufficient" air flow (as compared to "too much"). This input signal comes from the hot wire, correct?
2. Lambda being in open loop: I am not sure what even to ask about this. I had always thought it started in open loop - and went to close loop after a short period of time during which the O2 readings were made, and if said readings were within a pre-specified range. Is this correct?
Well, thanks again. I'll go out to the car and see if I get 12 volts and can try the "relay installed" test.
Jim