Griff specific hot start, something new and simple

Griff specific hot start, something new and simple

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Discussion

NicBowman

Original Poster:

478 posts

218 months

Sunday 31st July
quotequote all
Hi, specific for Griff, where the dash removal is a pain. I had one hot start incident, so time to fix. Firstly, thanks to all who have freely given information and taken time to provide solutions, particularly Dave from HF solutions.

Simply put, the starter circuit has four bits:-

1, Ignition switch
2, immobiliser
3, wiring to starter
4, starter itself.

The full starter solenoid current passes through the ignition switch, the immobiliser relay and the wiring. About 10 to 12 amps, I believe.

The smoking gun is always the immobiliser as TVR wired the higher current starter through the lower rated relay. So, an issue that will inevitably become a problem.

A hot start kit works by bypassing the starter solenoid current via a new solenoid, but leaves the immobiliser switch taking a small switching current. Can work, but your immobiliser relay will be less than perfect, so not a perfect solution. I also don’t like a new solenoid in the footwell and more random connections to the battery power and earth.

I have simply bypassed the immobiliser, putting a new wire between the ignition switch, easily accessed, to the starter wiring (accessed in the passenger footwell). This bypasses all the TVR wiring behind the dash, plus the immobiliser relay. Plus, you can thread the wire without removing the dash,

This leaves:-

1, ignition switch
2, wiring to starter
3, starter

The ignition switch always took full starter solenoid current, so no change there. But, built to take it.

This is dead easy. I haven’t put in details of how to wire, as folks get weird in terms of security. But, honestly anyone wanting to hot wire a Griff is probably well informed, plus a little crazy…

Hope this helps someone, cost me £5 for 24 amp wire in white / Red. It also works.

If not this, second most likely issue is the starter or your battery!

This is not wrong, if you wish to propose, please come well prepared with your physics text books!

Best


Nic

sixor8

4,336 posts

248 months

Sunday 31st July
quotequote all
I admire your perseverance; my Griff developed the non-start, hot or cold! So I decided to cough up for a replacement system. It was plug and play from Abacus.

Personally though, I found dash removal relatively simple. Drop the steering column (2 bolts), 2 screws on the dash. Remove stereo, one wing nut on the left, pull out dash. Mind the leather! Disconnect the electric plugs and remove from car.

I've had to remove the dash on 2 x Chimaera, now that IS tricky! Especially the heater control wheels... frown

NicBowman

Original Poster:

478 posts

218 months

Monday 1st August
quotequote all
Hi, I have removed the dash previously. As you say, watch the leather! Not terrible but holds some fear with me over peripheral damage possibilities.

I agree replacement immobiliser a better solution, again Dave from DH can provide a correctly wired version. Will do that next time I take the dash out.

Best


Nic

Belle427

6,520 posts

213 months

Tuesday 2nd August
quotequote all
The way most people use these cars I’d probably bypass the immobiliser altogether.
Obviously check insurance implications first but just my 2 p worth.

Polly Grigora

10,229 posts

89 months

Friday 5th August
quotequote all
NicBowman said:
I have simply bypassed the immobiliser, putting a new wire between the ignition switch, easily accessed, to the starter wiring (accessed in the passenger footwell). This bypasses all the TVR wiring behind the dash, plus the immobiliser relay. Plus, you can thread the wire without removing the dash,

This leaves:-

1, ignition switch
2, wiring to starter
3, starter
Amazing simple mod

Car is now back to how it would have been if the immobiliser wasn't fitted

Obviously there are no plugs along the new cable which is a big plus

It's too easy, something must be wrong with the modsmile



David Beer

3,960 posts

247 months

Friday 5th August
quotequote all
Polly Grigora said:
Amazing simple mod

Car is now back to how it would have been if the immobiliser wasn't fitted

Obviously there are no plugs along the new cable which is a big plus

It's too easy, something must be wrong with the modsmile

Simply not correct, the wiring for the RR “had a relay “ fitted just before it went to the starter solenoid, if tvr had not removed it, no body would of had a hot start issue. Oh well, it’s all part of the character, ie TVR !

Loubaruch

1,047 posts

178 months

Friday 5th August
quotequote all
A relay is much easier to change than the ignition switch!

If you bypass the immobiliser DBs mod still provides protection for the ignition switch, around 12 amps through those contacts is not good practice.

NicBowman

Original Poster:

478 posts

218 months

Friday 5th August
quotequote all
Hi, the ignition switch always took the full starter solenoid current. So no change. I agree the hot start kit reduces the current through the ignition switch, but, is that the problem? Anyone know the rating of the ignition switch, as opposed to opinion?

Nic

Polly Grigora

10,229 posts

89 months

Saturday 6th August
quotequote all
NicBowman said:
Anyone know the rating of the ignition switch, as opposed to opinion?

Nic
Similar Lucas switches were rated at 15/16amps

The type of GM switch fitted to your car is prone to failure

Only way around the problem is to wire a relay into the circuit

Don't use a standard 30 Amp relay

70 Amp relay with the bigger terminals is up to the job


David Beer

3,960 posts

247 months

Saturday 6th August
quotequote all
Polly Grigora said:
Similar Lucas switches were rated at 15/16amps

The type of GM switch fitted to your car is prone to failure

Only way around the problem is to wire a relay into the circuit

Don't use a standard 30 Amp relay

70 Amp relay with the bigger terminals is up to the job

Not heard of switch failed. 70 amp relay for 13-15 draw is pointless.

NicBowman

Original Poster:

478 posts

218 months

Saturday 6th August
quotequote all
Hi, David Beer is of course correct when saying a relay on the starter feed would have been better, there would have been no hot start issue. Which is what a hot start kit does. This effectively reduces the current flow through the ignition switch and immobiliser to a low current (1amp ish). This would protect the immobiliser and ignition switch.

If you have a good reliable car, I would recommend you fitting the hot start kit before you get a problem.

Once you get a problem, the issue is more complex. The immobiliser will be suffering some damage. The Hot start kit may still fix your issues, but your immobiliser is not what it once was..

All my mod does is bypass the immobiliser, using the ignition switch to carry the 10 to 12 Amps to engage the starter relay, as it always did. The ignition switch can take this current. Hence, seems to me to be a very easy fix if you have an issue. It bypasses the smoking gun. Very quick and cheap.

I will eventually replace the immobiliser so I know it is good, and fit the hot start kit to lower the current carried in the circuit.

Nic