Jump to content
ChrisQ

Automotive Gurus

Recommended Posts

Just now, ChrisQ said:

Hi Sean, 

No, not at the time but plan to the first time i mess with the truck again, from my understanding if they are not within range there's not further point going forward until that faulty part is replaced.

Now i'm very curious myself and are about to get dirty. Should i even begin to trust my $5.99 multimeter for that or do you think it would suffice? 

Multimeters are pretty straightforward so I would guess it's fine.  You could test it on a circuit you know works just to verify the values you get are reasonable - or you could use an actual resistor for an even better test if you had one laying around.  An old fashion filament lightbulb could work as well (but I couldn't tell you exactly what resistance value to expect) or even the bulb out of your dome light.

Share this post


Link to post
Share on other sites
Posted (edited)

No response at all. On any of them. Does it need to be cranking over?

Edit: Yeah, i just just used a speaker and it's pretty spot on. but thanks for those tips.

Edited by ChrisQ

Share this post


Link to post
Share on other sites
4 minutes ago, ChrisQ said:

No response at all. On any of them. Does it need to be cranking over?

Should not need to be cranking for resistance - this is just checking the integrity of the pickup coils.  When you say no response, is it showing infinite resistance or none?  Infinite would indicate a broken wire and none a short to ground somewhere.  If that circuit is bad (broken pickup coil?) I would worry that you are not getting the proper timing signature from the CPS to the ECM and hence it isn't providing the correct control signal to the coil and hence no output to the distributor.  I would verify that your multimeter is working and make sure you are testing between the correct pins on the distributor and ground but it is worrisome (to me anyway).  Maybe I am completely misreading this and someone better at schematics (which would be just about anyone who works with electricity) will chime in.  Hope I'm not leading you astray here.

Share this post


Link to post
Share on other sites

Like @albertareef said you should just be checking resistance to verify that the pickup coils are OK.   

image.png

Share this post


Link to post
Share on other sites
Posted (edited)
18 minutes ago, albertareef said:

Should not need to be cranking for resistance - this is just checking the integrity of the pickup coils.  When you say no response, is it showing infinite resistance or none?  Infinite would indicate a broken wire and none a short to ground somewhere.  If that circuit is bad (broken pickup coil?) I would worry that you are not getting the proper timing signature from the CPS to the ECM and hence it isn't providing the correct control signal to the coil and hence no output to the distributor.  I would verify that your multimeter is working and make sure you are testing between the correct pins on the distributor and ground but it is worrisome (to me anyway).  Maybe I am completely misreading this and someone better at schematics (which would be just about anyone who works with electricity) will chime in.  Hope I'm not leading you astray here.

I didn't think it needed to be cranking, good thing, cause i'm alone. Trust me nobody can be worse at trying to read a schematic than me. I spent hrs last night downloading high resolution schematics of all the electrical of my truck and almost melted my brain trying to make sense of some of them, but anyway, I don't understand "infinite response on none" basically, if i hold the pins together i get 00.6 consistently, when test was performed it reads just as it sits pins not touching anything and that reading is 1 followed by a long space and a dot.

I used a speaker to test the multimeter with a known ohm and it was only off by 00.1

 

 

Edited by ChrisQ

Share this post


Link to post
Share on other sites
Posted (edited)
26 minutes ago, cjmdh said:

Like @albertareef said you should just be checking resistance to verify that the pickup coils are OK.   

image.png

I'm sorry for my automotive ignorance but i don't even know where or what the pickup coils even look like and could not find pics. :doh: If there might be something wrong there too.

Edited by ChrisQ

Share this post


Link to post
Share on other sites

I drew a diagram of the pic i posted before i went out there so i made sure i was testing the right ones and to record the readings.

Share this post


Link to post
Share on other sites
24 minutes ago, ChrisQ said:

I didn't think it needed to be cranking, good thing, cause i'm alone. Trust me nobody can be worse at trying to read a schematic than me. I spent hrs last night downloading high resolution schematics of all the electrical of my truck and almost melted my brain trying to make sense of some of them, but anyway, I don't understand "infinite response on none" basically, if i hold the pins together i get 00.6 consistently, when test was performed it reads just as it sits pins not touching anything and that reading is 1 followed by a long space and a dot.

I used a speaker to test the multimeter with a known ohm and it was only off by 00.1

 

 

Hey Chris,

so that reading with the pins (leads) not touching each other (1 with the dots) is basically infinite resistance (open circuit. The reading with the pins directly touching is basically zero resistance.  If you are getting infinite resistance when testing the pins on the distributor to ground then there is a likely an issue with the pickup coils.  From what I can tell the crankshaft position sensor (of which the pickup coils would be a part) is internal to the distributor so there is nothing to see without dismantling that. From that original thread I posted these do not appear to be serviceable parts so a new (or used) distributor would be in order. Before you went there, however, I would have someone verify for you as I’m guessing that may not be easy to come by or cheap. 

Good idea on the speaker test - I should have thought of that.  Surprised it came out as close as it did since those values are “nominal” and represent an averaged resistance across the whole driver and crossover network (unless you tested a raw driver you had laying around).  

  • Thanks 1

Share this post


Link to post
Share on other sites
1 hour ago, albertareef said:

Hey Chris,

so that reading with the pins (leads) not touching each other (1 with the dots) is basically infinite resistance (open circuit. The reading with the pins directly touching is basically zero resistance.  If you are getting infinite resistance when testing the pins on the distributor to ground then there is a likely an issue with the pickup coils.  From what I can tell the crankshaft position sensor (of which the pickup coils would be a part) is internal to the distributor so there is nothing to see without dismantling that. From that original thread I posted these do not appear to be serviceable parts so a new (or used) distributor would be in order. Before you went there, however, I would have someone verify for you as I’m guessing that may not be easy to come by or cheap. 

Good idea on the speaker test - I should have thought of that.  Surprised it came out as close as it did since those values are “nominal” and represent an averaged resistance across the whole driver and crossover network (unless you tested a raw driver you had laying around).  

I'm just letting some of this sink in, yeah that part goes from $129-$229. Got that bad news yesterday talking with autozone.

Wouldn't a broken wire not give the same result? With the distributor being just fine?

 

Thanks again

Share this post


Link to post
Share on other sites
6 minutes ago, ChrisQ said:

I'm just letting some of this sink in, yeah that part goes from $129-$229. Got that bad news yesterday talking with autozone.

Wouldn't a broken wire not give the same result? With the distributor being just fine?

 

Thanks again

Yep but you tested directly on the terminals mounted on the distributor correct?  Not sure if there are any accessible wires between those and the internal components. On my phone so hard to go back and look at the schematic. 

Share this post


Link to post
Share on other sites
Posted (edited)
1 hour ago, albertareef said:

Yep but you tested directly on the terminals mounted on the distributor correct?  Not sure if there are any accessible wires between those and the internal components. On my phone so hard to go back and look at the schematic. 

Edit: no, not at first but i did try those too and got the same result. Didn't pay enough attention to making sure i was on the right ones though. 

 

Yes, directly from the terminals on the harness that i also ran that audible trace on. All four ended abruptly in the same area like they should have if that was the end of the wire.

Edited by ChrisQ

Share this post


Link to post
Share on other sites
9 hours ago, cjmdh said:

Like @albertareef said you should just be checking resistance to verify that the pickup coils are OK.   

image.png

G1  -  G-  = 160.8

G2  - G-   = 161.2

NE  -  G-  = 202.0

  • Like 1

Share this post


Link to post
Share on other sites
4 hours ago, ChrisQ said:

G1  -  G-  = 160.8

G2  - G-   = 161.2

NE  -  G-  = 202.0

Ok - that looks good (what did you do differently?). This would suggest the circuit in the distributor is good so perhaps your apparent continuity issue in the wiring harness is the culprit.  

Share this post


Link to post
Share on other sites
11 hours ago, albertareef said:

Ok - that looks good (what did you do differently?). This would suggest the circuit in the distributor is good so perhaps your apparent continuity issue in the wiring harness is the culprit.  

Did the test the way it was originally asked for me to do. :laugh:

Told you guys i have no idea what i'm doing :tongue:

Spent all day ripping my alarm out and reversing everything they did. I very much enjoyed ripping that relay out of there that can cut my ignition resulting in my no spark problem, next would be tackling the worst part, finding and repairing the 4 broken lines from the distributor harness.

I also tested resistance in my VAF/VAFM

Distributor high-tension cable resistance = 5.38

25k ohm max 

CaptureVAF1.png

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×