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Chasing a Short to Ground Issue - RJM EFI Harness and Denso Starter

tim70

Full Member
Joined
Feb 1, 2007
Messages
257
Loc.
SF Bay, CA
I'm trying to chase down a short to ground issue that I think I have narrowed down to either the RJM EFI Harness or the Denso starter (automatic version). Two issues that I can't figure out if they are correct:

1) The wiring for the Denso starter has a wire going from the starter side of the solenoid to the "small" connector on the starter as described in the following instructions:

http://www.svapowerproducts.com/html/ford_pmgr_retro_fit_instructio.html

(although my starter does not have the same look to the example Denso Starter).

If I hook up a continuity meter between the ground and this small wire, I get continuity indicating that it's connected to ground. Should this be the case?

2) On the RJM EFI Harness, I have a similar issue, but with the purple wire labeled "EFI Start" that should be hooked up to a start signal (in my case the S terminal of the starter solenoid). It also has continuity between ground and the terminal. Is this also correct?

I started down this road chasing a short on the under dash wiring harness related to the turn and marker signals and found very weird (at least to my expectations) interconnectivity to ground.

Any input? BTW, the truck starts and runs fine... I want to double check these two situations before I fry something.

Thanks, Tim
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,344
Starter wiring looks ok. I think what you see with the meter is the low resistance of the starter solenoid coil windings. Should be a few ohms of resistance, not 0 (short to ground).

Same type thing with the efi wire. It goes to a coil to energize a relay (same as starter solenoid). Measure ohms. Should be more ohms than starter coil.

Most continuity functions on meters have a range of "acceptable ohms values" where they will indicate continuity. They might range from 0-100 ohms. I never use the continuity function for this reason, I always measure the ohms directly. It gives me a better indication of whats happening in a circuit.
 
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tim70

tim70

Full Member
Joined
Feb 1, 2007
Messages
257
Loc.
SF Bay, CA
Thanks viperwolf. I double checked the ohm readings and this is what I got when one meter lead connected to the battery ground and the other (+) connected to the following:

-Wire to small terminal of the starter (disconnected from the starter side of starter solenoid): 0.3 ohms

-Purple EFU Start Wire (disconnected from S terminal of starter solenoid): no continuity

-"S" terminal of starter solenoid (with and w/o purple wire connected): 3.4 ohms

I'll move on and look elsewhere for the dash wiring issue if this looks okay.

Tim
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,344
Thanks viperwolf. I double checked the ohm readings and this is what I got when one meter lead connected to the battery ground and the other (+) connected to the following:

-Wire to small terminal of the starter (disconnected from the starter side of starter solenoid): 0.3 ohms

-Purple EFU Start Wire (disconnected from S terminal of starter solenoid): no continuity

-"S" terminal of starter solenoid (with and w/o purple wire connected): 3.4 ohms

I'll move on and look elsewhere for the dash wiring issue if this looks okay.

Tim

Looks good. Sometimes it helps to pull the bulbs when checking resistance in the lighting. PM me if you have too much trouble getting it sorted out. I know a few things about EB wiring.
 

chuck

Bronco Guru
Joined
Aug 14, 2001
Messages
6,474
Loc.
Ingram, Texas
I'm trying to chase down a short to ground issue that I think I have narrowed down to either the RJM EFI Harness or the Denso starter (automatic version). Two issues that I can't figure out if they are correct:

1) The wiring for the Denso starter has a wire going from the starter side of the solenoid to the "small" connector on the starter as described in the following instructions:

http://www.svapowerproducts.com/html/ford_pmgr_retro_fit_instructio.html

(although my starter does not have the same look to the example Denso Starter).

If I hook up a continuity meter between the ground and this small wire, I get continuity indicating that it's connected to ground. Should this be the case?

2) On the RJM EFI Harness, I have a similar issue, but with the purple wire labeled "EFI Start" that should be hooked up to a start signal (in my case the S terminal of the starter solenoid). It also has continuity between ground and the terminal. Is this also correct?

I started down this road chasing a short on the under dash wiring harness related to the turn and marker signals and found very weird (at least to my expectations) interconnectivity to ground.

Any input? BTW, the truck starts and runs fine... I want to double check these two situations before I fry something.

Thanks, Tim
Why go to the new style starter and keep that old solenoid? Run a battery cable from the (+) post of the battery to the (+) terminal of the starter then run a start wire to the new starter and be done with it? As far as your short, why do you think you have one? If your battery is going dead over night turn everything off and put a test light between the battery (+) post and the cable then start un hooking things until the light goes out.
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,344
I kept my solenoid when I installed a new style starter because it's a good connection point for high current things.
 
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tim70

tim70

Full Member
Joined
Feb 1, 2007
Messages
257
Loc.
SF Bay, CA
Why go to the new style starter and keep that old solenoid? Run a battery cable from the (+) post of the battery to the (+) terminal of the starter then run a start wire to the new starter and be done with it? As far as your short, why do you think you have one? If your battery is going dead over night turn everything off and put a test light between the battery (+) post and the cable then start un hooking things until the light goes out.

Point well taken, I basically followed Ray's instructions. I also have several connections on the bat side of the solenoid, so it worked out well.

I think the whole grounding thing was me over-thinking some of the issues...
 

chuck

Bronco Guru
Joined
Aug 14, 2001
Messages
6,474
Loc.
Ingram, Texas
Wiring it that way you are activating a sol. to activate a sol.. If you want to use the stock one for a place to connect things but run the start and Ign. wire down to the new starter. But I think better to make those connections at the battery and delete the old sol.
 

bronco italiano

Contributor
Bronco Guru
Joined
Feb 1, 2004
Messages
2,117
Since the denso is RRRAAAYYY's I would like to hear his input/diagram to do it chuck's way if it's an ok setup. I would love to delete my starter solenoid but need a diagram as I am electrically challenged. BI
 
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