Friend’s truck won’t start

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65 Dartman

1 of None 65 Dart Sedan Delivery
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Trying to help a friend out with his 77 Dodge truck. He had to replace both the engine and underdash harness as it fried from the one of the alternator field wires back into the underdash harness to the fuse panel. He had the alternator tested and if course it was fried. He located another complete 77 harness and replaced them, the alternator and voltage regulator. Went to start the truck, idled good then died with no start after that All he has is a test light. I told him check for spark at Nr 1 plug wire then for spark from the coil to the dizzy. No spark there either however he said both terminals on the coil showed power with the key on the run position. So I stopped by to see if I could See anything out of the ordinary but forgot my multimeter. He mentions the ignition switch is a universal for multiple Mopars except 75/76 Valiants and Darts. I spent some time making sure the ignition wires went to according the Chilton/Haynes underdash harness even though the color codes didn’t mstch the underdash harness. Anyway it all seemed to check out. I told him I suspect the coil. Is my analysis correct? If not what else can he check for?
 
Tell him to turn the key to the start position and physically HOLD IT THERE. If it starts, put a ballast resistor on it.
 
jump positive coil to batt + and short starter relay to crank motor. would bypass all ignition circuit. I fit runs, then its the ignition start/run wiring.
 
This could be a number of issues, wiring faults, wrongly wired, or failure of component, or even just simple bad connection

Pretty difficult at this point

I would start by directly jumpering power to the coil+ and see if you have spark by jumpering the starter solenoid. If not, make sure ignition ECU is getting power. You need a meter or at least a test lamp

With key "in run" but engine stopped, you should have around 6-8V at coil + If you have full battery voltage, the coil is not drawing current, suspect and check coil, or ECU box MAKE CERTAIN ECU box (and VR) ARE GROUNDED. MUSt

Wiggle connectors in/ out, the ECU connector, distributor pickup, and bulkhead connector. Remove connectors and inspect for corrosion, and "work" in/ out several times to "scrub" terminals and "feel" for tightness
 
If you have the proper power to the coil in the run position, it's not the ballast resistor or bad wiring. If the starter cranks the engine over fine, it's not a battery problem either. Most likely the coil or ECU took a dump, has a bad ground, or, in rarer cases, the pickup coil in the distributor went bad. Verify that you don't have spark coming out of the coil......not at the spark plug. It's always possible you could have a bad rotor or cap.
 
Did you guys get er running?

He said he jumpered from the battery to the plus on the coil with the key in the run position. Then jumped the starter relay and it didn’t start. He said his test light still shows both sides of the coil electrically hot; i told him change the damn coil. He hasn’t reported back
 
the ECU, points, pick-up plate, turns the coil on and off to get spark i would think no spark at coil wire, ya gotta look at those things i listed.
 
He said he replaced the dizzy electronics, swapped the coil, ECU and ballast resistor with supposedly good used and said screw it when nothing changed. He’s kind of lost electrically speaking and doesn’t have a lot of patience with it. Without being there I assume he’s following the advice from you guys that I’ve passed along
 
Make sure the ballast is receiving power and has output also.
 
well, swapping in wiring may be an issue, he'd need a wiring diagram etc. Also keep in mind if the wiring is totally screwed he may be shorting out parts like the ECM
 
well, swapping in wiring may be an issue, he'd need a wiring diagram etc. Also keep in mind if the wiring is totally screwed he may be shorting out parts like the ECM

hus wiring diagram is this multi year diagrams in Haynes/Chiltons.

i asked him this morning dud he actually run a jumper wire from the battery to the coil - no he DID NOT! He was checking with a test light at the coil. I told him he was getting goid advice and start with the jumper wire
 
I would "in the mix as suggested"

Get the ignition system down to it's barest form and hot wire it and go from there. May have numerous issues

Problems with mis-matched / incorrect wiring
Problems with loose/ corroded or even imporoperly mated connectors
Problems with electrical components, coil, seconardy wiring, iginition box, pickup in dist.
 
I made him a jumper cable using some 12 gauge wire I had. I told him start with battery to coil and jump the srarter relay. After he reports back to me, I post what he said!
 
My friend figured the coil was bad - all 3 that he tried! So I gave him a genuine Mopar coil, the truck started and after a minute or two died. He happened to be looking at the fuse he installed when it blew. So he comes by asking what I thought was wrong. I said your alternator is putting out too much juice. But it’s a new rebuilt unit. Get it checked anyway! So he pulled it and the first piece of bad news was the sticker on it “Rebuilt in China”, 2nd was after getting it checked, it was putting out way too much. He figures that was why the coil was showing hot on both plus and negative. So he took it back and the counter guy commented Here’s another one. I’ve got a bunch of OEM alternators from cars I’ve parted out so he’s gonna take a couple and get them checked and see how it goes
 
I know reading now that the ballast is probably not the issue, but I always shake my head when people run right over the suggestion to turn the key and hold it in the start position to see if it'll start and say "run this wire here and there and everywhere", when ONE SIMPLE action can rule out a lot of stuff and takes two seconds to do. lol
 
Yes Sir , but he’s pretty hard-headed! He finally trued jumpering from the battery to the coil, which likely was now burnt out and said screw rw it

The fuse (which replaced a fusible link) that blew was a 30 amp so the alternatir was really putting out some amps (and the test showed nearly 16 volts!).
 
My friend figured the coil was bad - all 3 that he tried! So I gave him a genuine Mopar coil, the truck started and after a minute or two died. He happened to be looking at the fuse he installed when it blew. So he comes by asking what I thought was wrong. I said your alternator is putting out too much juice. But it’s a new rebuilt unit. Get it checked anyway! So he pulled it and the first piece of bad news was the sticker on it “Rebuilt in China”, 2nd was after getting it checked, it was putting out way too much. He figures that was why the coil was showing hot on both plus and negative. So he took it back and the counter guy commented Here’s another one. I’ve got a bunch of OEM alternators from cars I’ve parted out so he’s gonna take a couple and get them checked and see how it goes
NORMALLY the alternator does not "put out too much" all on it's own. The common problems are (in no order)

1....Problems in wiring..........such as we had a member here got the greed field wire pinched under a rocker cover bolt, grounding it. That is the "grounding" or "control" wire from the VR
2....Voltage drop in the harness or ground circuit, causing the VR to "ramp up" voltage
3.....Bad VR..........Usually a VR fails "no charge" but they can fail the other way and it is usually one or the other, either "full" or "no" charge
4.....CHECK FOR missing or broken field insulator hardware. DO this by using a meter to check continuity. The two field connections should show very low continuity between the two and OPEN (infinity) from one or both to ground (case) of the alternator.
 
Another place to check is on the back of the alt gauge. It gets hot and the plastic melts and the terminals get loose. Then u have this. Wry same overcharging problem. One way to check that is have it idling with the lights and hearer fan on. It will be discharging till u rev it up some. Kim
 
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