DFI and ECM Discuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.

maf relay connector at 20vdc

Old 12-30-2017, 02:58 PM
  #1  
Junior Member
Thread Starter
 
Mok1987's Avatar
 
Join Date: Dec 2017
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts
maf relay connector at 20vdc

I have been having an issue with my 86 iroc z where the 20amp fuel circuit fuse will blow as soon as the ignition is turned to the on position. when i disconnect the maf power relay, then the car will start.
I have gone through 3 seperate mass airflow sensors and the issue persists.
Ihave ohmed out the sender unit from the bulkhead under the car the guage wire reads around 40 and the other wires are near 1 and 0.1 (this is with one tester on the weatherpak and the other touching the tank.)
>how can i tr4oubleshoot this issue effectively?
>would a shorted ground in the harness cause a spike in voltage enough to blow the fuse every time?
>what color wires lead to the fuel sender from the p107 connector?

Last edited by Mok1987; 12-30-2017 at 03:04 PM. Reason: high voltage at relay connector changed. harness was too close to the alternator
Old 12-30-2017, 03:06 PM
  #2  
Junior Member
Thread Starter
 
Mok1987's Avatar
 
Join Date: Dec 2017
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts
Re: maf relay connector at 20vdc

CORRECTION ABOUT THIS THREAD. the issue is about a fuel fuse blowing, the high voltage issue seems to have gone away since i moved the harness away from the rear of the alternator
Old 12-30-2017, 03:50 PM
  #3  
Moderator

iTrader: (2)
 
Six_Shooter's Avatar
 
Join Date: Mar 2006
Posts: 4,356
Received 10 Likes on 8 Posts
Car: 1973 Datsun 240Z/ 1985 S-15 Jimmy
Engine: Turbo LX9/To be decided
Transmission: 5-speed/T-5
Axle/Gears: R200 3.90/7.5" 3.73
Re: maf relay connector at 20vdc

Where were you using as a ground source? Sometimes using an incorrect source can show more (or less ) voltage than is actually on a circuit.
Old 12-30-2017, 03:54 PM
  #4  
Junior Member
Thread Starter
 
Mok1987's Avatar
 
Join Date: Dec 2017
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts
Re: maf relay connector at 20vdc

on the relay connector i used the ground wire, and then i used chassis ground to verify it. On the fuel tank side of the disconnected fuel pump harness i used the fuel tank as the ground to get my ohm readings. would you know where and which wires i need to get to to isolate that segment of harness from the rear bulkhead?
Old 12-30-2017, 04:08 PM
  #5  
Junior Member
Thread Starter
 
Mok1987's Avatar
 
Join Date: Dec 2017
Posts: 23
Likes: 0
Received 0 Likes on 0 Posts
Re: maf relay connector at 20vdc

what i mean is,, where does the other side of the sender harness connect and where do i find the wires for the fuel pump/sender on that connector
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
FireballXL5
Tech / General Engine
7
02-26-2016 04:29 PM
Iroc_Z28
Electronics
4
01-28-2002 05:41 AM
JT 85 TA 305
Electronics
1
12-08-2001 06:15 AM


Thread Tools
Search this Thread
Quick Reply: maf relay connector at 20vdc



All times are GMT -5. The time now is 03:09 PM.