# Ford Crown Vic Electrical Problem
**URL:** https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043
**Category:** Factual Questions
**Created:** [February 21, 2007, 2:13am UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043 "2007-02-21T02:13:09Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@nebco9](https://boards.straightdope.com/u/nebco9)
#### Post date: [February 21, 2007, 2:13am UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/1 "2007-02-21T02:13:09Z")
I’m driving a taxi these days. I’ts a 1998 Ford Crown Victoria. Early last Saturday evening I noticed the dash panel lights were out and replaced a fuse to fix the problem. Yes I used the same amp fuse. No big deal, although I’ve never had to replace a fuse before. I don’t know if this had anything to do with the **big problem** that came up the next night, or just a co-incidence, but I guess it should be mentioned.
Everything was fine until Sunday close to midnight. It was rainig a little and just as I hit a small puddle of water with my right front wheel(Another co-incidence or maybe a cause?), the engine shut down entirely. I was able to coast to the side of the road and tried to restart it. No go. The engine would crank fine, headlights and horn worked great, dispatch computer and radio all OK, but no way would the engine start.
The next morning I had it towed to the cab garage and they started checking it out. It’s been 2 days and they can’t come up with the source of the problem. From what they tell me, there is no spark and no pressure from fuel pump. They’ve checked the crank sensor, engine computer, fuses, wiring, modules and everything else they can think of.
I know that sometimes auto electrical problems can be a real bitch to solve, but the mechanics are scratching and shaking their heads over this one. Any chance that one of our teeming millions might be an expert auto electrical mechanic? Or has anyone had a similar problem and found a solution?
I’m out of work and off the road right now and really don’t want to junk the cab and buy another one. Any help would be appreciated.
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### Author:  [@Booker57](https://boards.straightdope.com/u/Booker57)
#### Post date: [February 21, 2007, 2:19am UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/2 "2007-02-21T02:19:55Z")
In the trunk you will find a semi-hidden switch. Check the manual for where it is. It is called an Inertia switch and it will cut off the fuel pump when it is activated. Hit a big bump and _click_ no fuel pump power.
Former Lincoln-Mercury tech.
Thought you hit a pothole. I could be wrong but is a free thing to check out.
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### Author:  [@nebco9](https://boards.straightdope.com/u/nebco9)
#### Post date: [February 21, 2007, 2:36am UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/3 "2007-02-21T02:36:42Z")
[QUOTE=Booker57]
In the trunk you will find a semi-hidden switch. Check the manual for where it is. It is called an Inertia switch and it will cut off the fuel pump when it is activated. Hit a big bump and _click_ no fuel pump power.
Former Lincoln-Mercury tech.
Thought you hit a pothole. I could be wrong but is a free thing to check out.
[/QUOTE]
Know about the fuel shut-off switch. It’s one of the first things I checked.
There’s also the “no spark” problem. With that **and** the “no fuel pump” problem together everybody seems to be focused on an electrical problem.
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### Author:  [@Gary\_T](https://boards.straightdope.com/u/Gary_T)
#### Post date: [February 21, 2007, 3:49am UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/4 "2007-02-21T03:49:29Z")
Carefully check the wiring harness under the battery and in front of the right front wheel. There is often corrosion and wire deterioration there, and a splash of water may have been the final straw.
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### Author:  [@Balthisar](https://boards.straightdope.com/u/Balthisar)
#### Post date: [February 21, 2007, 12:57pm UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/5 "2007-02-21T12:57:37Z")
Are fusible links still common on car electrical systems? It may be worth it to have your garage start checking continuity on all of those. Heck, electrical systems can be funky, but it’s simply to see if wire _n_ has continuity from one point to the other. It’s also fairly simple to apply 12V directly to the fuel pump to see if it runs period.
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### Author:  [@nebco9](https://boards.straightdope.com/u/nebco9)
#### Post date: [February 21, 2007, 7:12pm UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/6 "2007-02-21T19:12:09Z")
Day 3 and the cab still isn’t running. ☹
Just got back from talking to the mechanic at the cab garage.
**Gary T** : He already checked the wiring harness under battery and by the right front wheel and says everything _seems_ OK.
**Balthisar** : He says the car _does have_ fusible links and he has already checked those. Due to the fact that the car wasn’t getting any spark, he hadn’t tested the fuel pump independantly by itself, but he is doing so now.
The mechanic _seems_ to be fairly knowledgable, although he isn’t an “electrical specialist”. He’s trying, but admits he’s stumped so far by this one. He called an “auto electrical” person yesterday to come over and help him out, but the guy didn’t show. He knows I’m friends with most of the owner-operaters with the cab company and I’ve told him his reputation is on the line, and he better come through. 😃
If he doesn’t find the problem by tomorrow, I guess I’ll have the car towed to an auto electrical specialist shop and give them a shot at it. In the mean time, I’m making arrangements to lease a cab tomorrow from the company fleet so that I’ll at least have some money coming in.
Thanks for suggestions. If anybody else have any more ideas they would be appreciated.
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### Author:  [@Gary\_T](https://boards.straightdope.com/u/Gary_T)
#### Post date: [February 21, 2007, 7:50pm UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/7 "2007-02-21T19:50:20Z")
Loss of spark and fuel delivery at the same time suggests that the PCM power relay (EEC-V relay) isn’t delivering power. Typically, this is caused by interruption (open circuit) in the yellow/black wire that energizes it, from Fuse 12. If that wire isn’t hot, it needs to be traced (or bypassed). Wiring faults are also common where the harness goes from the right front to along the lower radiator framing, and around the left front wheel area. It may be necessary to pull the inner fender lining(s), and to uncover/unwrap the wiring harness to find the break.
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### Author:  [@nebco9](https://boards.straightdope.com/u/nebco9)
#### Post date: [February 21, 2007, 8:52pm UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/8 "2007-02-21T20:52:38Z")
[QUOTE=Gary T]
Loss of spark and fuel delivery at the same time suggests that the PCM power relay (EEC-V relay) isn’t delivering power. Typically, this is caused by interruption (open circuit) in the yellow/black wire that energizes it, from Fuse 12. If that wire isn’t hot, it needs to be traced (or bypassed). Wiring faults are also common where the harness goes from the right front to along the lower radiator framing, and around the left front wheel area. It may be necessary to pull the inner fender lining(s), and to uncover/unwrap the wiring harness to find the break.
[/QUOTE]
Thanks again.
I’ll see if he’s checked those things out. I did ask him about the ECC relay and fuel pump relay modules since they’re marked and easy for even me to see. He said he tried switching out the modules themselves and it didn’t help. I’ll ask him about the " the yellow/black wire that energizes it, from Fuse 12" thing and see if he’s looked into that. I’ll also ask him if he’s checked the wiring harness where you described it.
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### Author:  [@nebco9](https://boards.straightdope.com/u/nebco9)
#### Post date: [February 21, 2007, 9:21pm UTC](https://boards.straightdope.com/t/ford-crown-vic-electrical-problem/393043/9 "2007-02-21T21:21:23Z")
**Gary T** : I just got off the phone with the mechanic and he told me he has just gotten it running. I think he did so by by-passing some wiring. He seemed very interested in your information about “Typically, this is caused by interruption (open circuit) in the yellow/black wire that energizes it, from Fuse 12” part.
It seems that your information will help him locate _where_ in the wiring harness the problem is. Now, if he can just fix it, I’ll be back on the road again soon!
Again, many thanks.