Using EHA test harness
 

Before throwing $154 at a new EHA, I bought this test cable from MB, to determine if my EHA is drawing proper mA.

Correct me if I'm wrong, but apparently #1 connects to the EHA; #2 to the amp meter; #3 is where I'm lost (it's a two pole male connector with a 3rd dummy post). I've read it connects to the engine's wire harness but I've no clue where this connection is.

Can someone familiar with this harness' use please help me out?

TIA!

http://www.members.aol.com/vandrysen/harness.jpg

Wouldn't #3 plug into the connector you just unplugged from the EHA?

!!!!
 

Hah! Makes perfect sense Stephen ... I'll give it a try!

Thanks :D

Did you read Steve Brotherton's reply to my question about what the ma readings should be?

No I haven't. Manual says 20mA with key on, ignition off. Reading should fluctuate at idle speed and operating temp. 2 to 6mA with simulated 20c, and O2 sensor unplugged but of course I don't have the 2.5k OHM test cable so I'll have to skip this test. Are there other readings to test?

If so, point me please to the post you refer to Stephen.

Thanks again!

Search my posts for "Have I stumbled into the gremlins lair? EHA valve? I don't know how to paste the thread title or I would. Anyway Steve's reply is the first one. Let us know what your results are. I'm very interested.

My readings came out fine:

+20mA with ignition on, engine off
+7-9mA (fluctuating) with engine at operating temp, idle speed

Disconnect EHA:

resistance at EHA, ignition on, engine off: 19 OHM

So, apparently I have a bad EHA or valve seal. I'm gonna replace the seal first and see if my lambda readings stabilize.

Stephen, you're welcome to borrow this harness if you want. Let me know ASAP and I'll send it out today.

Wait now!! As usual , I'm confused!!
 

If your readings came out to spec, wouldn't that mean that the EHA is good?? We may need to get 'The Man" in on this one!! Oh Mr. Brotherton>>>> where art thou????

I might have a very slow leak, either internally in the EHA or a bad seal. Although there's no smell of fuel, I noticed some gunk on the connectors and on and around the EHA. But there's also some gunk on and around the intake runners so hellifIknow. Don't know if this is EHA gunk or general engine gunk. :D :D

I'm assuming that a leaky EHA would not affect current readings?!

Of course I haven't checked my fuel regulator pressure yet which might shed some light on this.