Focus Fanatics Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
59 Posts
Discussion Starter · #1 ·
Short version...

Me and my 2005 ZXW Duratec with 80k miles were happily cruising along two weekends ago and I noticed I had no turn signals or functioning gauges, immediately I knew I was running on battery power and had limited run time to find a place to pull over, so I made a u-turn and parked in a radiator repair place I knew.

I pulled out the volt meter from my work bag and it was less than 12v, then I shut it off and didn't restart, no big surprise. So I put a charger on it from the radiator shop to charge while I waited for tow truck to arrive, that way we could start it when he got there to drive it on the flatbed.

I had it towed to one of those old-school shops that rebuilt starters and alternators for 50 years, these guys are like mad scientists, they know their stuff more than anyone when it comes to these systems. I am blessed to have one of these shops locally and I have used them to rebuilt lots of my units of the last 40 years. I always tell my own customers, don't put a junk parts store alternator/starer on your vehicle that will only last 2 weeks or 2 years, take your original one to these guys and have it meticulously rebuilt correctly with quality parts and it will last another 100k miles.

So he got the alternator off, tore it down, found one of the brushes burned completely through the copper into the plastic. He completely rebuilt it with all new parts, new bearings, and a HD rectifier that doesn't put out more amps, its just slighter beefier that can handle more amps.

All is good, charges good, no issues... except I've noticed that when I am sitting at a red light, when the turn signals are on the engine idle is slightly surging, for example like 500 rpm to 600 rpm to 500 rpm to 600 rpm and over and over. If I turn off the signals the idle smooths out perfect steady. It doesn't do this for any other kind of load, I can put high beams on, radio, high fan blower, defrost, and idle is steady.

It seems the turn signals puts the engine idle into an osculation and it didn't do it for the last 5 years with the original alternator. Any thoughts on this weirdness?
 

·
Registered
Joined
·
17,771 Posts
Maybe excess resistance in the turn circuits? See if both sides do it.

Barely warm idle with all loads off and alt should have 14.0 volt or higher measured at battery. Let car sit overnight and battery car off needs to be 12.3 volts or higher.
 

·
Registered
2012 Focus SE hatchback black
Joined
·
563 Posts
amc49 has good advice. Perhaps the flasher is on it's way out or you have a short in the system(wire, bulb, melted plug).
I'd call the electrical rebuild shop and ask them if they have any idea what it might be.
As usual src153 has nothing to offer of value to anyone. Hand signals.... What great help you are, not.
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #5 ·
Thanks for the replies and suggestions, I just think its weird that it never did that before the rebuild. I talked to the rebuild guru and he said to bring it down to take a look.
 

·
Registered
Joined
·
17,771 Posts
It can possibly be the alt, had one do the same on the zetec type alt and didn't after I rebuilt it. Can't say which part exactly it was though. I suspect a bad diode maybe.

Zetec diodes are particularly easy to check as they crack the leads most commonly and easy to see. The others if diode simply goes bad are harder to check as you are checking the entire diode package and cannot tell individual ones unless they are each separated from the array they are soldered into.

A quick alt test for AC ripple may show it.
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #7 ·
Thanks for the additional tips, I just remembered I forgot to check and see if it does it with both turn signals, so I'll check tomorrow. I hope its not the alternator!
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #8 ·
Here is what I found so far...

  • The alternator checks out fine
  • The idle surges up and down at full operating temperature when either turn signal is on or hazzard flasher
  • The idle smooths out when flasher is off
  • Volt meter readings are 14.4 when at idle
  • Volt meter readings with signals/flashers on and idle surging the readings go 14.0 to 14.4 to 14.0 to 14.4 and so on
 

·
Registered
2006 ZX5 2.0, 2004 ZX3 SVT EE. 2004 ZX3 SVT
Joined
·
2,477 Posts
Here is what I found so far...

  • The alternator checks out fine
  • The idle surges up and down at full operating temperature when either turn signal is on or hazzard flasher
  • The idle smooths out when flasher is off
  • Volt meter readings are 14.4 when at idle
  • Volt meter readings with signals/flashers on and idle surging the readings go 14.0 to 14.4 to 14.0 to 14.4 and so on
First. Remove and clean All of your grounds. From the battery to the fender. Underneath the airbox. Lifting hook on back of cylinder head to fender. Cluster ground under fuel cutoff switch.
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #10 ·
Thanks for the suggestion, when they did the alternator they cleaned all the grounds under the hood and sprayed them with a protectant that has transparent gold color to it. Since this problem started immediately after the alternator overhaul, that made me wonder if when they cleaned all the grounds that maybe one of them is not grounded so well. (they tried to do a good thing and maybe it backfired)
 

·
Registered
Joined
·
17,771 Posts
I'd look as well at any resistance in the big positive battery charging cable.
 

·
Registered
2012 Focus SE hatchback black
Joined
·
563 Posts
Perhaps one of the grounds is loose or not making proper contact. Recheck the battery clamps too.
Does this issue happen on both left and right signals? You said that you were going to check that.
You may have a bad signal bulb that's shorting out the system or perhaps a pin or wire connector is damaged.
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #13 ·
Cleaned all grounds under hood, no difference.

It doesn't matter what turn signal or hazards, all the same up & down idle response.

Note, this car is in excellent condition inside and out, tip-top maintenance, and with only 75k miles.
 

·
Registered
2004 Focus Wagon, Zetec DOHC, Auto
Joined
·
1,623 Posts
Have you checked to see if the idle air control valve got disconnected when the alternator work was done?
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #15 ·
Funny you would say that... no but, I developed the famous "stalling when coming to a stop" the very next day (most likely coincidence) and thought it was the IAC, so I put a new one in and that didn't fix it, but then cleaned the MAF and that fixed it. After reconnecting the battery I let it idle for 5 minutes then took it for a ride to relearn.
 

·
Registered
2004 Focus Wagon, Zetec DOHC, Auto
Joined
·
1,623 Posts
Have you check for a vacuum leak? Something is keeping the engine from maintaining proper idle and it seems likely to not be electrical related as you have already checked the usual suspects. I would look for something physically wrong such as a vacuum hose off (or split) as a result of replacing the alternator.
 

·
Registered
Joined
·
59 Posts
Discussion Starter · #18 ·
Idle is perfect since I cleaned MAF, not related, idle surge with turn signals/hazzard still exists.

That ground in photo above was cleaned when alternator was rebuilt, but I will re-check it to be sure...
 

·
Registered
2006 ZX5 2.0, 2004 ZX3 SVT EE. 2004 ZX3 SVT
Joined
·
2,477 Posts
Idle is perfect since I cleaned MAF, not related, idle surge with turn signals/hazzard still exists.

That ground in photo above was cleaned when alternator was rebuilt, but I will re-check it to be sure...
It needs checking with an ohmmeter as it can appear fine visually. It is easily damaged.
 

·
Registered
2006 ZX5 2.0, 2004 ZX3 SVT EE. 2004 ZX3 SVT
Joined
·
2,477 Posts
I'm surprised no one has mentioned the hatch wiring as that is a common wiring failure point. Have you taken the car back to the alternator shop?
 
1 - 20 of 23 Posts
Top