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Re: Heater Relay Dropout Issue/ **RESOLVED

When I initially tested the motor wire harness I used a test light
and it lit with the switch on on the Blue wire (the other is black).
I got the light on with the switch on so I made the mistake that it
was the correct wire when the hot positive is the black wire (logical
right:) ) so I looked at the schematic and turns out the black is the
switched positive, the blue gives a voltage until the last switch
position 8V down to 0. I metered the black and its solid over 12 at
all speeds so I think moving the wire will resolve the issue. Duh...
Should have removed the plug first. I think this is the safest bet as
the relay for the fan only indicates the switch is on, having the fan
on is a safer bet.


Can't wait to figure out the electric power steering:) I suspect the
ECU gets a feed from the Engine ECU to let it know the RPM so the
alternator is up to supply amp or something- we'll see. All other
systems seem to work:)

Thanks


mark

Mark Dutko wrote:

> I think the most likely would be the switch but if it could handle
> the draw from the relay it should continue to work as the relay
> draw should remain the same? The wire to the relay is spliced right
> at the motor and the AC switch has been completely isolated from
> the rest of the car electronics. My 12v system runs off two 55A DC/
> DC and a med sized aux battery. I will run some voltage tests later
> and see what happens. Perhaps when I tested it the pack was
> disconnected and it was on the aux battery only- I'll test again.
>
>
>
> Thanks,
>
> Mark
>
>
>
> On Jul 27, 2007, at 7:38 AM, Phil Marino wrote:
>
>> HI, Mark
>>
>> I've set up my Echo the same way ( using the AC switch to control
>> the heater) so I'm familiar with the wiring.
>>
>> The fan takes a lot of current on high (about 12 amps) , so I can
>> think of two possibilities:
>>
>>
>> 1. Your 12V system voltage is dropping enough to drop the relay
>> out. Put a voltmeter on your 12V system and watch the voltage as
>> you change the fan speed.
>>
>> 2. There is enough voltage drop in the AC switch or wiring to
>> allow the relay voltage to drop when the fan is on high.
>>
>> To check this, put a voltmeter on the relay coil and watch as you
>> change fan speeds.
>>
>> What relay are you using?? It could be that the AC switch itself
>> is the culprit - it's only designed to send a signal to the A/C
>> amplifier, not power a large relay directly.
>>
>> Mine is set up so that the AC switch only drives a small ( 17 ma
>> coil) relay , and THAT relay drives the larger KUEP relay ( 100 ma
>> coil). You could try something like that.
>>
>>
>>
>> A third possibility ( this seems unlikely to me) is that the
>> blower switch is faulty and is not grounding the heater relay
>> ( which needs to be on to power the AC switch) when teh blower
>> switch is in the "high" position. Or, if the ground wire from the
>> heater switch were loose, it might have that same effect (because
>> there is more current through that ground wire when the fan is on
>> "high").
>>
>>
>> Phil
>>
>>
>>
>>
>>> From: Mark Dutko <[email protected]>
>>> Reply-To: [email protected]
>>> To: [email protected]
>>> Subject: Heater Relay Dropout Issue
>>> Date: Fri, 27 Jul 2007 06:49:38 -0700
>>>
>>> I have my heater relay for my 220V pack grounded on one 12v side
>>> and the other going to the positive wire of my heater fan
>>> through a switch in the dash which used to be the AC switch,
>>> When the AC switch is on and the fan is turned on the relay
>>> makes contact on the first, second and third fan speed position
>>> but on the fourth position or the highest, the relay drops out
>>> and I need to turn the fan off to get it to contact again. I
>>> have a diode across the relay coil (not sure if needed) and
>>> that's it. Any suggestions as to a fix for this and why it
>>> happens on the high fan speed setting?
>>>
>>> Thanks,
>>>
>>> Mark
>>>
>>
>> _________________________________________________________________
>> http://newlivehotmail.com
>>
>>
>
>
 
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