Restarting the 7 - No Power

[Boxologist]

Now here's a odd problem. Tried restartring the Caterham last week.

The battery had lost the strength to turnit over by itself during the winter and required a boost. Putting the car into gear would cause the car to stall. I checked the battery and the fluid level was low, so I added some deionized water and put the battery in the basement for a day or so on the trickle charger.

fast forward a few months, put the battery in and teh car won't start. even worse, NO power whatsoever. the standard tach gauge lights don't register. No sound of teh fuel pump priming. NOTHING. reattach the booster and still nothing.:confused: I press the inertia switch, no dice. cleaned the terminals, bolts, nuts, and other leads with steel wool. checked all the fuses, everything OK. voltage across the battery is ~12 volts. other car batteries confirm the meter is in teh ballpark and not in error.

in the morning i will going thru the wirring o see if there is a short or something eaten away, but that no power registers has me at a loss. any other fault points that stick out? I can only imagine the ECU as the other part that can kill everything.:eek:

[slomove]

There is usually a main fuse somewhere (or a fusible link). Not sure about Caterham, though....

Does the power at least get to the fuse box?

Turned on the big red T shaped battery switch ;-)

Gert

[pi7ot]

12v measured at the battery is marginal. A freshly charged battery should be showing a minimum of 12.7 volts.
A second observation i would make is that your battery may be showing 12v but it has actually failed(broken plate), or too discharged to recover. The 12v it shows is merely a surface charge. When a load is placed on the battery and you measure the voltage, it will drop below 10v if it has failed.
load test the battery first.

if the battery is in tip top shape ,yet there's nary a click or glow in the cluster, then Gert's observation is spot on.
On Birkins there is a 30A fuse in the main power supply and it is located in the engine bay. Not sure where it is on Cats, but will be of similar amperage.

m

[tnttim]

12v measured at the battery is marginal. A freshly charged battery should be showing a minimum of 12.7 volts.
A second observation i would make is that your battery may be showing 12v but it has actually failed(broken plate), or too discharged to recover. The 12v it shows is merely a surface charge. When a load is placed on the battery and you measure the voltage, it will drop below 10v if it has failed.
load test the battery first.

m

Exactly, One wasy would be to just turn on the headlight and drop a meter across the battery. If it dies then you have a faulty or dead battery. Also be careful, If a battery get low enough it can actually develope negative voltage. If your not carefull and hook up the bat that way you can fry the ECU.

The other thing to do is clean the battery terminals. It may look like they are hooked up and clean but they can be just a slight corrosion on the terminal preventing contact.
If you own a good quality battery charger then you can hook up the battery in the car and turn on the accessories. I would not recommend trying to start it yet though.

Start at the battery and test the voltage from the pos+ bat terminal to the frame (-). If no voltage check the ground strap at the frame and clean the connection.
Then just move down the positive side of the wiring to the frame with your volt meter.

(+)Batt---------(MainSwitch)------(Fuses)----ECT....


Hope this helps.

Tim

[TheDingo8MyBaby]

12v measured at the battery is marginal. A freshly charged battery should be showing a minimum of 12.7 volts.
A second observation i would make is that your battery may be showing 12v but it has actually failed(broken plate), or too discharged to recover. The 12v it shows is merely a surface charge. When a load is placed on the battery and you measure the voltage, it will drop below 10v if it has failed.
load test the battery first.


This doesn't necessarily mean the battery has failed. There could be a short somewhere or a high resistance.

I think since you have extra batteries you know are good, try swapping the battery. It sounds like it is most likely your culprit.

[jlumba81]

You might want to check out the ignition switch to see if it has a loose wire or a short.

[Boxologist]

There is usually a main fuse somewhere (or a fusible link). Not sure about Caterham, though....
ECU fuse is on the passenger's knee under the scuttle.
Does the power at least get to the fuse box?
i'll check this tommorow beore the dentist. joy...
Turned on the big red T shaped battery switch ;-)

Gert

12v measured at the battery is marginal. A freshly charged battery should be showing a minimum of 12.7 volts.
A second observation i would make is that your battery may be showing 12v but it has actually failed(broken plate), or too discharged to recover. The 12v it shows is merely a surface charge. When a load is placed on the battery and you measure the voltage, it will drop below 10v if it has failed.
load test the battery first.

if the battery is in tip top shape ,yet there's nary a click or glow in the cluster, then Gert's observation is spot on.
On Birkins there is a 30A fuse in the main power supply and it is located in the engine bay. Not sure where it is on Cats, but will be of similar amperage.

m

the functioning battery from the subaru has the same result on the 7. 7 won't start.

Exactly, One wasy would be to just turn on the headlight and drop a meter across the battery. If it dies then you have a faulty or dead battery. Also be careful, If a battery get low enough it can actually develope negative voltage. If your not carefull and hook up the bat that way you can fry the ECU.

The other thing to do is clean the battery terminals. It may look like they are hooked up and clean but they can be just a slight corrosion on the terminal preventing contact.
If you own a good quality battery charger then you can hook up the battery in the car and turn on the accessories. I would not recommend trying to start it yet though.

Start at the battery and test the voltage from the pos+ bat terminal to the frame (-). If no voltage check the ground strap at the frame and clean the connection.
Then just move down the positive side of the wiring to the frame with your volt meter.

(+)Batt---------(MainSwitch)------(Fuses)----ECT....


Hope this helps.
in the AM
Tim

This doesn't necessarily mean the battery has failed. There could be a short somewhere or a high resistance.

I think since you have extra batteries you know are good, try swapping the battery. It sounds like it is most likely your culprit.
doesn't look promising. hopefully i can get teh battery in question into a anther 7 to confirm.


You might want to check out the ignition switch to see if it has a loose wire or a short.
pulled the plastic boot off the switch. it felt like a 4 prong relay, but one prong had no wires leading to it. i never checked the ignition switch when it was OK. I'll get under and take a picture.

[MHKflyer52]

Will the car bump start with the battery and ignition on. If it will then I would check the starter. I have had an MG Midget that did the same thing and found the starter to be frozen from sitting.

[Hank]

Tap the starter with a hammer?

[TheDingo8MyBaby]

Tap the starter with a hammer?

Haha...people may think you're crazy...but sometimes the solenoid gets stuck this totally works.

I had a starter go out right before finals when I was in college. I had to do this for a week every time I started the car.

[jlumba81]

Check the grounds. You might have to just get a multimeter and start checking the wiring starting at the battery.

[Hank]

Has the car been sitting up and field mice had access to it? They like to nibble on wiring harnesses. Check for mice poo around the perimeter of the car.

[Kitcat]

No, no, no. Every one's wrong!

Think of your Caterham as you would a woman. You haven't looked at her all winter and have spent every moment in the company of her rivals. Now that it's Spring and you are back in the mood, you are trying to get her to turn on, but guess what, she's miffed.

I think there is hope but don't expect it to be easy. She just wants to see you suffer a little. And you have to make amends and show your sorry: start spending some money on her. Offer her a new starter, or maybe a solenoid, pull the hood and touch her wires and keep saying, "What's wrong, I want to make it better" If you treat her like a (trailer) queen, she will eventually come around.

I speak from personal experience (about Caterhams, that is).

[bball7754]

I've had a similar experience with my Caterham, although it would ultimately start. I have a Crossflow, so no modern electronics to deal with. But I would turn the key and get nothing. Starter didn't engage. But after numerous attempts, it would work and the engine would start as normal.

Spoke to Ben, and he said that the connections to the ignition switch can become either loose or corroded. It's near the top of my list to get under there and clean things up.

Steve

[locost7018]

Damn, Kitcat. You hit the nail right on the head!! My xflow loves to have money thrown at it. Russ

[Boxologist]

update: Today was clear before going into work and had time to check the car.
I didn't expect a starter issue as no power was visible with the key turned in the ignition. wacked the started a few times any way, No change in (non)start up behavior.
Took the battery booster off teh charger and tested that. No change in (non)start up behavior.
Started testing voltages. 1. the 20 amp fuse into the passenger bay shows no power.
2. the big (0?) gauge wire from the battery shows 12+ V at the alternator. a red and green emerge from the alternator. i trust they will have AC power and show me nothing now? the green i was able to track to a connection which seperated and found no voltage. that circuit continued into the engine harness iirc.
3. a second red wire, ~14g into a 5A fuse comes off teh battery and goes directly into the ECU. power makes it to the fuse.
4.Took the wires off the ignition switch. no power in the 3 wires.
5. wasn't in the mood nor the time to randomly strip wires and check for voltage.

PS. Mike, bite your tongue.:p

[jlumba81]

Trace the wires off the ignition switch. There is supposed to be a hot wire that has power at all times. Hopefully someone on the forum who owns a 7 can narrow down which wire it is. Hmmm.....I suppose you can try running a wire directly from the battery to the ignition wire, bypassing the faulty wire. Make sure the car is in neutral first cause you may start cranking it. Hope that helps.

[Boxologist]

ran a direct power lead to the ignition. car started to crank fine when teh key was turned. i start finding an electrical specialist today.

[jlumba81]

Don't really need a specialist, just a lot of patience and a good electrical multimeter tester. You can buy a decent one at radioshack. If you already have a tester you can test the ignition switch to see which wire is supposed to have power. Then you trace that wire until you find the where the break is. Then its a matter of replacing a bad connector or bad wire.

I've troubleshooted worse. A jeep liberty w/ no functioning brake lights. Ended up tearing out the whole interior except for the dash. Problem was a leaking roof rack rail letting water in the cabin and corroding a connector underneth the rear seats. Car had at least 1 inch of water in it when I pulled the carpet.

[jlumba81]

Got an update? I'm curious as to what was wrong.

[Boxologist]

dropped off friday, picked up today. have to get some red electrical tape to make sure this 'problem' doesn't happen again. at least some other issues got sorted as well(speed sensor[known], reverse switch[known], leaking fuel flex line[new one to me]). just got to sort some other issues like darty steering and maybe some loosing wires to the coolant temp gauge.

[Croc]

Its great to hear that you are mobile again. What was the final diagnosis from the electrics? I would not mind knowing to file away in brain for when it happens to me. After taking 3 weeks to work out why my brake lights would not work (hydraulic switch failure in pedal box) I can always use a few lessons from other people's experiences with electrics.

cheers

[Boxologist]

battery was connected in reverse.

DOH:banghead:

its awesome having a reverse light thats more than cosmetic now. :seeya:
and i'm pretty sure the darty steering isn't a bad steering rack, i have to tighten a set screw in between the 2 steeing columns. can't wait till i get the Quick release on!:driving:

[Croc]

battery was connected in reverse.


I just love these cars - we are always getting into scrapes, spins, strife or silliness with them. Life would be boring without them! :auto:

[Boxologist]

a box of yellow rollbar padding (non SFI) arrived yesterday. i made sure to order extra, u want some when your 7 is in motion again?

[Croc]

Many thanks for the offer Jon - but I got some in the garage that I have not installed yet. Its amazing how one bang of the head convinced me to buy some!

Anyway....need to heal the arm and finger before I can fix the car!